DR1200-DK - RF Monolithics - Datasheet.Directory

File: 400-1436.doc

Rev: B, 1999.03.05

Virtual Wire Development Kit Manual for DR1200-DK and DR1201-

Virtual Wire Development Kit Hardware Warranty

Special Notices

1 Virtual Wire Development Kit Introduction

1.1 Purpose of the Virtual Wire Development Kit

1.2 Intended User

1.3 General Description

1.4 Key Features

1.5 Development Kit Contents

2 Low-Power Wireless Data Communications

2.1 Operational Considerations

2.2 Regulations

2.3 Example Applications

2.4 FAQs

3 Developing a Virtual Wire Application

3.1 Simulating the Application

3.2 I/O and Power Considerations

3.3 Communications Protocol

3.4 Antenna Considerations

3.5 Internal Noise Management

3.6 Final Product Testing

3.7 Regulatory Certification

Regulatory Authority

Product Certification

Certification Testing

4 Installation and Operation

4.1 Development Kit Assembly Instructions

4.2 Data Radio Board

Antenna Options

4.3 Protocol Board

Node Programming

RS232 Interface

LED Functions

4.4 Terminal Program

Installation

Configuration

Operation

5 Theory of Operation

5.1 Data Radio Boards

I/O Interface

TR1000/TR1001 ASH Transceiver

Specifications

5.2 Protocol Board

I/O Interface

RS232 Interface

Protocol Microcontroller

CMOS/RS232 Level Converter

Specifications

5.3 Protocol Firmware

Description

Message Format

5.4 Terminal Program

Description

Source Code Listing

A Drawings

ASH Receiver Block Diagram & Timing Cycle

ASH Transceiver Block Diagram

Antenna Mounting

Node Programming

DR1200 and DR1201 Data Radio Schematic

DR1200 and DR1201 Data Radio Bill of Materials

DR1200 and DR1201 Data Radio Component Placement

916.5 MHz Test Antenna Drawing

868.35 MHz Test Antenna Drawing

PB1001 Protocol Board Schematic

PB1001 Protocol Board Component Placement

PB1001 Protocol Board Bill of Materials

Virtual Wire Development Kit Hardware Warranty

Limited Hardware Warranty. RF Monolithics, Inc. (“RFM”) warrants solely to the purchaser that the

hardware components of the Virtual Wire® Development Kit (the “Kit”) will be free from defects in materials

and workmanship under normal use for a period of 90 days from the date of shipment by RFM. This limited

warranty does not extend to any components which have been subjected to misuse, neglect, accident, or

improper installation or application. RFM’s entire liability and the purchaser’s sole and exclusive remedy for

the breach of this Limited Hardware Warranty shall be, at RFM’s option, when accompanied by a valid

receipt, either (i) repair or replacement of the defective components or (ii) upon return of the defective Kit,

refund of the purchase price paid for the Kit. EXCEPT FOR THE LIMITED HARDWARE WARRANTY SET

FORTH ABOVE, RFM AND ITS LICENSORS PROVIDE THE HARDWARE ON AN “AS IS” BASIS, AND

WITHOUT WARRANTY OF ANY KIND EITHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING BUT

NOT LIMITED TO THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTABILITY OR

FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow the exclusion of implied warranties,

so the above exclusion may not apply to you. This warranty gives you specific legal rights and you may also

have other rights which vary from state to state.

Limitation of Liability. IN NO EVENT SHALL RFM OR ITS SUPPLIERS BE LIABLE FOR ANY

DAMAGES (WHETHER SPECIAL, INCIDENTAL, CONSEQUENTIAL OR OTHERWISE) IN EXCESS OF

THE PRICE ACTUALLY PAID BY YOU TO RFM FOR THE KIT, REGARDLESS OF UNDER WHAT

LEGAL THEORY, TORT, OR CONTRACT SUCH DAMAGES MAY BE ALLEGED (INCLUDING,

WITHOUT LIMITATION, ANY CLAIMS, DAMAGES, OR LIABILITIES FOR LOSS OF BUSINESS

PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR FOR INJURY TO

PERSON OR PROPERTY) ARISING OUT OF THE USE OR INABILITY TO USE THE KIT, EVEN IF RFM

HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. BECAUSE SOME STATES DO NOT

ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL

DAMAGES, THE ABOVE LIMITATION MAY NOT APPLY TO YOU.

Special notice on restricted use of Virtual Wire Development Kits

Virtual Wire® Development Kits are intended for use solely by professional engineers for the purpose of

evaluating the feasibility of low-power wireless data communications applications. The user’s evaluation

must be limited to use of an assembled Kit within a laboratory setting which provides for adequate

shielding of RF emission which might be caused by operation of the Kit following assembly. In field testing,

the assembled device must not be operated in a residential area or any area where radio devices might be

subject to harmful electrical interference. This Kit has not been certified for use by the FCC in accord with

Part 15, or to ETSI I-ETS 300 220 or I-ETS 300 220-1 regulations, or other known standards of operation

governing radio emissions. Distribution and sale of the Kit is intended solely for use in future development

of devices which may be subject to FCC regulation, or other authorities governing radio emission. This Kit

may not be resold by users for any purpose. Accordingly, operation of the Kit in the development of future

devices is deemed within the discretion of the user and the user shall have all responsibility for any

compliance with any FCC regulation or other authority governing radio emission of such development or

use, including without limitation reducing electrical interference to legally acceptable levels. All products

developed by user must be approved by the FCC or other authority governing radio emission prior to

marketing or sale of such products and user bears all responsibility for obtaining the FCC’s prior approval,

or approval as needed from any other authority governing radio emission.

If user has obtained the Kit for any purpose not identified above, including all conditions of assembly and

use, user should return Kit to RF Monolithics, Inc. immediately.

The Kit is an experimental device, and RFM makes no representation with respect to the adequacy of the

Kit in developing low-power wireless data communications applications or systems, nor for the adequacy

of such design or result. RFM does not and cannot warrant that the functioning of the Kit will be

uninterrupted or error-free.

The Kit and products based on the technology in the Kit operate on shared radio channels. Radio

interference can occur in any place at any time, and thus the communications link may not be absolutely

reliable. Products using Virtual Wire® technology must be designed so that a loss of communications due

to radio interference or otherwise will not endanger either people or property, and will not cause the loss of

valuable data. RFM assumes no liability for the performance of products which are designed or created

using the Kit. RFM products are not suitable for use in life-support applications, biological hazard

applications, nuclear control applications, or radioactive areas.

RFM and Virtual Wire are registered trademarks of RF Monolithics, Inc. MS-DOS, QuickBASIC, and

Windows are registered trademarks of Microsoft Corporation.

1 Virtual Wire® Development Kit Introduction

1.1 Purpose of the Virtual Wire Development Kit

The Virtual Wire Development Kit is a tool for evaluating the feasibility of a low-power

wireless data communications application. The kit also facilitates the development of

the actual system. In addition, the modules in the kit are available from RF Monolithics,

Inc. (RFM) for use in system manufacturing.

1.2 Intended Kit User

The Virtual Wire Development Kit is intended for use by a professional engineer with

a working knowledge of data communications. The kit itself is not intended as an end

product, or for use by individuals that do not have a professional background in data

communications. Please refer to the Special Notices section in the front of this manual.

1.3 General Description

The Virtual Wire Development Kit allows the user to implement low-power wireless

communications based on half-duplex packet transmissions. The kit contains the

hardware and software needed to establish a wireless link between two DOS-based

computers with RS232C serial ports. The kit includes two communications nodes, with

each node consisting of a data radio board and host protocol board, plus accessories.

The DR1200-DK kit operates at 916.5 MHz, and the DR1201-DK operates at

868.35 MHz.

1.4 Key Features

The Virtual Wire Development Kit includes a number of key features:

• “Out of the box” operation between two DOS-based PC's

• 3 Vdc low-current UHF data radio transceivers (916.5 MHz)

• Excellent receiver off-channel interference rejection

• Wide dynamic range receiver log detection and AGC for resistance to on-channel

interference

• Reference antennas

• 4.5 Vdc low-current protocol boards based on an ATMEL AT892051 microcontroller

• On-board CMOS logic to RS232C level conversion with bypass provisions for direct

CMOS logic interface

• Packet link-layer protocol with ISO 3309 error detection and automatic packet

retransmission; up to 32 message bytes per packet transmission (ASCII or binary)

• DC-balanced data coding for robust RF transmission performance

• Simple packet protocol to application layer interface & example application software

• Diagnostic LEDs for system performance evaluation

• Up to 15 different node addresses supported; jumper programmable

1.5 Development Kit Contents

• Two data radio transceiver boards

• Two host protocol boards

• Two reference antennas

• 3.5" floppy disk with example application software

• Manual

2 Low-Power Wireless Applications

2.1 Operational Considerations

Low-power wireless (RF) systems typically transmit less than 1 mW of power, and

operate over distances of 3 to 60 meters. Once certified to comply with local

communications regulations, they do not require a license or "air-time fee" for

operation. There are more than 60 million systems manufactured each year that utilize

low-power wireless for security, control and data transmission. Many new applications

for low-power wireless are emerging, and sales are expected to top 100 million systems

per year by the end of the decade.

The classical uses for low-power wireless systems are one-way remote control and

alarm links, including garage door openers, automotive "keyless entry" transmitters, and

home security systems. Recently, a strong interest has developed in two-way data

communications applications. These low-power wireless systems are used to eliminate

nuisance cables on all types of digital products, much as cordless phones have

eliminated cumbersome phone wires. RFM's Virtual Wire Development Kits are

intended to support the design of these types of low-power wireless applications.

Most low-power wireless systems operate with few interference problems. However,

these systems operate on shared radio channels, so interference can occur at any

place and at any time.

Products that incorporate low-power wireless communications must be designed so that

a loss of communication due to radio interference or any other reason does not create a

dangerous situation, damage equipment or property, or cause loss of valuable data.

2.2 Regulations

While low-power wireless products do not have to be individually licensed, they are

subject to regulation. Before low-power wireless systems can be marketed in most

countries, they must be certified to comply with specific technical regulations. In the US,

the FCC issues this certification. In most of Europe and Scandinavia, certification is

based on ETSI standards, and administered by the PTTs.

While technical regulations vary from country to country, they follow the same general

philosophy of assuring that low-power wireless systems will not significantly interfere

with licensed radio systems. Regulations specify limitations on fundamental power,

harmonic and spurious emission levels, transmitter frequency stability, and transmission

bandwidth.

2.3 Example Applications

Applications for low-power wireless data communications are growing very rapidly. The

following list of example applications demonstrates the diversity of uses for low-power

wireless technology:

• Wireless bar-code readers and bar-code label printers

• Smart ID tags for inventory tracking and identification

• Wireless automatic utility meter reading systems

• Wireless credit card readers and receipt printers for car rentals, restaurants, etc.

• Communications links for hand-held terminals, HPCs, PDAs, and peripherals

• Portable and field data logging

• Location tracking (follow-me phone extensions, etc.)

• Sports telemetry

• Surveying system data links

• Engine diagnostic links

• Polled wireless security alarm sensors

• Authentication and access control tags

• Arcade games

2.4 FAQs

1. Why does the Virtual Wire Development Kit include a packet protocol

microcontroller? Why not connect the data radio board directly to a computer serial

port?

You can hook a data radio board directly to a computer serial port (using an RS232

to 3 V CMOS level converter). However, the results are not likely to be satisfactory.

First, error detection is limited to byte parity checking, which will let many errors go

undetected. Also, the DC balance in the data can be very poor, which will greatly

reduce the data radio’s range.

Packet protocol is used extensively in two-way data communications. For example,

the Internet and digital cellular phones use packet transmissions. While there are

many packet protocols in use, they all provide a basic set of features, including an

effective means for transmission error detection, and routing support (such as a “to”

and “from” address). This allows error free data communications to be performed in

a highly automatic way. The protocol microcontroller used in the Virtual Wire

Development Kit provides error detection and automatic message retransmission,

message routing, link failure alarms and DC-balanced packet coding.

2. What is the operating range of my low-power wireless systems?

In our tests in an electrically quiet outdoor location, we easily communicate

60 meters with the DR1200-DK and DR1201-DK. However, operating range in a

given situation is influenced by building construction materials and contents when

indoors, and by other radio systems operating in the vicinity, and noise generated by

nearby equipment. The Virtual Wire Development Kit can be taken into a target

environment and used to help gain a sense of operating range for the proposed

system. See the Appendix in the ASH Transceiver Designer’s Guide for additional

information.

3. Can I communicate between more than two nodes in the same location with a low-

power communications link?

Yes. One of the benefits of packet transmissions in channel sharing. In the case of the

Virtual Wire Development Kit, each protocol board can be programmed to have one

of fifteen addresses, with address “0” reserved for messages that are broadcast to all

nodes. For example, node 1 can be transmitting bar-code readings to node 2 while

node 4 is transmitting bar-codes to node 7 in the same location. So long as the average

channel usage is less than about 12%, randomly transmitted messages will get though

without excessive transmission “collisions” and transmission retries.

3 Developing a Virtual Wire Application

3.1 Simulating the Application

There are hundreds of potential applications for short-range wireless communications

links. Because there can be so many different variables in a potential application,

simulating the application is often the best way to gain insight into its feasibility. Virtual

Wire Development Kits can be very helpful in simulating potential applications. The

following simulation check list covers issues common to most low-power wireless

applications. The user should also consider what other specific issues apply to the

application being simulated:

• Maximum operating range required

• Type of operating environment (outdoor, indoor, indoor building construction, etc.)

• Number of nodes (transceivers) required in the application

• Node interaction (communications between pairs of nodes only, one master node

and several slave nodes, communications between any two nodes, etc.)

• Possible on-channel interference/noise sources (ISM equipment, electrical

equipment, nearby spread-spectrum systems, etc.)

• Channel usage (average and peak number of messages expected each minute,

average message transmission/acknowledgment duration, average percentage of

time the channel is in use, etc.)

• Message characteristics (average and maximum length; message type such as

data, telemetry, control codes, etc.)

• Antenna logistics (omnidirectional, directional, hidden, etc.)

• Environmental considerations

Indoor radio propagation is an issue for special consideration. In most indoor locations,

“dead spots” can be found where reception is very difficult. These can occur even if

there appears to be a line of sight relationship between two nodes. These “dead spots”,

or nulls, are due to multiple transmission paths existing between two locations because

of reflections off metal objects such as steel beams, concrete rebar, metal door, window

and ceiling tile frames, etc. Nulls occur when the path lengths effectively differ by an

odd half-wavelength. Deep nulls are usually very localized, and can be avoided by

moving either node slightly.

Diversity reception techniques are very helpful in reducing indoor null problems. Many

low-power wireless systems involve communications between a master and multiple

slave units. In this case, the master transmission can be sent twice; first from one

master and then again from a second master in a slightly different location. The nulls for

each master will tend to be in different locations, so a slave is very likely to hear the

transmission from one or the other master. Likewise, a transmission from a slave is

likely to be heard by at least one of the masters. Hand-held applications usually involve

some movement, so automatic packet retransmission often succeeds in completing the

transmission as hand motion moves the node through the null and back into a good

transmission point.

3.2 I/O and Power Considerations

The DR1200 and DR1201 Data Radio boards require a DC power supply in the range of

2.7 to 3.3 Vdc with less than 10 mV of ripple, and a peak current capability of up to

15 mA. Quiescent current in the receive mode is approximately 5.5 mA with a 3 volt

power supply. The average current with an RF signal being transmitted is approximately 6

mA and the peak current in the RF transmit mode is approximately 12 mA. Care must be

taken to avoid reversing the polarity of the power supply since diode protection is not

provided. Another concern is ESD as static-sensitive, devices are used on the Data Radio

board. Note the Protocol Board operates from 4.5 Vdc.

3.3 Communications Protocol

Almost all two-way wireless data communications use some form of packet protocol to

automatically assure information is received correctly at the correct destination. The

protocol provided with the Virtual Wire Development Kits is a link-layer protocol, and

includes the following features:

• 16-bit ISO 3309 error detection calculation to test message integrity

• 4-bit TO/FROM address routing with 15 different node addresses available

• ASCII or binary message support, up to 32 bytes per packet

• Automatic packet retransmission until acknowledgment is received; 8 retries with

semi-random back-off delays plus “acknowledge” and “link failure” alarm messages.

Also included with the Kits is a simple terminal program with source code to provide an

example of interfacing host (application) software to the Virtual Wire link layer

protocol. Most users will develop specific host software to match the needs of their

application. The protocol software does not require or support hardware flow control, so

the host software will have to do some timekeeping to interface the protocol software.

Study the source code listing and comments for the details of this interface. Users

familiar with hardwired packet networks may consider the 32 message bytes per packet

limit quite small. Packets sent by low-power wireless systems are kept deliberately short

to improve performance where on-channel burst interference and low signal-to-noise

conditions are often encountered.

3.4 Antenna Considerations

Suitable antennas are crucial to the success of a Virtual Wire application. Here are

several key points to consider in designing antennas for your application:

• Where possible, the antenna should be placed on the outside of the product. Also,

try to place the antenna on the top of the product. If the product is “body worn”, try to

get the antenna away for the body as far as practical.

• Regulatory agencies prefer antennas that are permanently fixed to the product.

Antennas can be supplied with a cable, provided a non-standard connector is used

to discourage antenna substitution (these connectors are often referred to as

“Part 15” connectors).

• An antenna can not be placed inside a metal case, as the case will shield it. Also,

some plastics (and coatings) significantly attenuate RF signals and these materials

should not be used for product cases, if the antenna is going to be inside the case.

• The antenna designs used in the kit are included in the Drawings section of the

manual. Many other antenna designs are possible, but efficient antenna

development requires access to antenna test equipment such as a vector network

analyzer, calibrated test antenna, antenna range, etc. Unless you have access to

this type of equipment, the use of an antenna consultant is recommended.

• A patch or slot antenna can be used in some applications where an external

antenna would be subject to damage. These types of antennas usually have to be

designed on a case-by-case basis.

3.5 Internal Noise Management

RF transceivers operating under FCC "Part 15" rules are sensitive to noise in the

passband of the receiver, because the desired transmitted signals are at very low power

levels. Commonly encountered internal noise sources are microprocessors, both for

control functions and computer functions; brush-type motors and high-speed logic circuits.

If the rise time and fall time of the clock for a microprocessor are fast enough to produce

harmonics in the frequency range of the receiver and the harmonics fall within the

passband of the receiver, then special care must be taken to reduce the level of the

harmonic at the antenna port of the receiver. If the engineer has the option, he should

choose a microprocessor that has the slowest rise and fall time he can use for the

application to avoid the troublesome harmonics in the UHF band. If possible, brush-type

motors should be avoided, since arcing of the brushes on the commutator makes a very

effective spark gap transmitter. If it is necessary to use a brush-type motor, spark

suppression techniques should be used. Such motors can be purchased with spark

suppression built-in. If the motor does not have built-in spark suppression, bypass

capacitors, series resistors and shielding may have to be employed. High-speed logic

circuits produce noise similar to microprocessors. Once again, the engineer should use

logic with the slowest rise and fall times that will work for his application.

The items listed below should be considered for an application that has one or more of

the above noise sources included. It may not be possible to follow all of these guidelines

in a particular application.

• Locate the RF transceiver and its antenna as far from the noise source as possible.

• If the transceiver must be enclosed with the noise source, remotely locate the antenna

using a coaxial cable.

• Terminate high speed logic circuits with their characteristic impedance and use

microstrip interconnect lines designed for that impedance.

• Keep PCB traces and wires that carry high-speed logic signals or supply brush-type

motors as short as possible. Such lines act as antennas that radiate the unwanted

noise.

• If possible, enclose the noise source in a grounded metal box and use RF decoupling

on the input/output lines.

• Avoid using the same power lines for the RF transceiver and the noise source or at

least thoroughly filter (RF decouple) such power lines. It is advisable to use separate

voltage regulators, if possible.

• If the antenna cannot be remotely located, place it as far from the noise source as

possible (on the opposite end of the pc board). Orient the antenna such that its axis is

in the same plane with the pc board containing the noise source. Do not run wires that

supply the noise source in close proximity to the antenna.

3.6 Final Product Testing

Any wireless data communications system must be thoroughly tested due to the

“anything can happen in any sequence” nature of wireless communications. It is highly

recommended that beta sites be chosen for operational system testing which represent

the “limit” situations the system can be expected to operate in.

Testing for regulatory certification is discussed in Section 3.7. It is recommended that

the user either establish an RF test range or a working relationship with a recognized

test lab early in the system development phase, to allow for periodic evaluation of the

system’s emissions during development. Many labs are experienced in solving radiation

problems that cause certification test failures and/or jamming of the low-power wireless

link. Identifying these types of problems early can save a lot of development time.

3.7 Regulatory Certification

Regulatory Authority - Worldwide, man-made electromagnetic emissions are controlled

by international treaty and the ITU (International Telecommunications Union) committee

recommendations. These treaties require countries within a geographical region to use

comparable tables for channel allocations and emission limits, to assure that all users

can operate with reasonable levels of interference.

Recognizing a need to protect their limited frequency resources, many countries have

additional local laws, regulations and government decrees for acceptable emission

levels from various electronic equipment, both military and commercial. By requiring

that each model of equipment be tested and an authorization permit issued after

payment of a tax (called a grant fee), the government attempts to control the sale of

poor quality equipment and also has record of the known manufacturers.

Enforcement and expectation of the local law varies, of course. USA, Canada, and

most European countries have adopted ITU tables for their respective radio regions.

Australia, Hong Kong and Japan also have extensive rules and regulations for low

power transmitters and receivers, but with significant differences in the tables for that

radio region. Most other countries have less formal regulations, often modeled on either

USA or EU regulations.

In any country, it is important to contact the Ministry of Telecommunications or Postal

Services to determine any local limitations, allocations, or certifications PRIOR to

assembling or testing your first product. The mildest penalty is often total loss of your

import, export and foreign exchange privileges.

These laws and requirements are applicable to the finished product, in the configuration

that it will be sold the general public or the end user. OEM components often can not be

certified, since they require additional non-standard attachments before they have any

functional purpose.

Unless otherwise marked, RFM Virtual Wire Development Kit modules have not been

certified to any particular set of regulations. Each module has suggested countries for

use, depending on current allocations and technical limits. Emissions from receivers

can be an unexpected problem, and the RFM modules have special features to help

with this part of the emission testing.

Product Certification - General requirements for emissions and ingressions ( called

susceptibility, if errors occur) are controlled by engineering standards of performance,

regulations, and the customer’s expectations.

In USA and Canada, for example, you must formally measure the emissions, file for a

certification or authorization, and affix a permanent marking label to every device, prior

to offering your system for sale. Regulations allow you to build only a small number

(usually 5 pieces) for testing and in-company use, before certification and marketing.

Trade shows and product announcements can be a problem for marketing, when the

products are advertised without proper disclaimers. With Internet access, go to

“www.fcc.org” for USA information or “www.ic.gc.ca” for Canada. The Canada rules are

RCC-210, Revision 2. FCC CFR 47, Parts 2 and 15, contains the needed information

for USA sales.

European Union (EU) requirements allow self-certification of some systems and require

formal measurement reports for other systems. In all cases, however, the directives

demand the “CE mark” be added to all compliant devices before any device is freely

shipped in commerce. In the EU, the EMC Directive also adds various tests and

expectations for levels of signal that will permit acceptable operation.

The EU directives introduce the concepts of a “cognizant body”, a “notification body”

and a “construction file”. Cognizant bodies are simply technical experts recognized by

the EU committees to review technical regulations and compliance. Any acceptable test

lab will have a preferred cognizant body for their certifications. Each regulatory body will

have at least one engineer designated as the notification body for that country, and he

receives any communication about certification or changes to a certified system. While

this may seem confusing, it does avoid the legal problems of engineering titles and

varied bureaucratic ministry names.

Construction files (CF) are a common format for presenting pictures, schematics and all

other information on the parts and processes used to actually build a certified system,

The report of antenna range measurements will be included in the CF. Your cognizant

body will review the construction file before granting the authorizations for CE mark and

EU identification label on your system.

The first problem in the EU is usually Border Customs, who have been trained to look

for the CE logo marking for all products. You may need special forms or permits to

simply ship pre-production models to your test lab. The Internet web site

“www.etsi.co.fr” has information for ordering the full EU marketing regulations.

Certification Testing - The emissions are measured in a calibrated environment defined

by the regulations. USA and Canada use an “open field” range with 3 meters between

the device under test (DUT) and the antenna. The range is calibrated by measurement

of known signal sources to generate range attenuation (correction) curves in

accordance with ANSI C63.4-1992.

EU measurement rules are based on a similar arrangement, but a “standard dipole”

antenna is substituted for the DUT to calibrate the range attenuation. Since the EU

measurements are comparison or substitution rules, they are often easier to follow for

informal pre-testing by the designer. ETSI-300-220 has drawings to completely describe

a typical test configuration.

The United States and Canadian requirements are contained in ANSI C63.4-1992,

including a step-by-step test calibration and measurement procedure. Since these rules

include range attenuation factors, one must make twice the measurements of the EU

test method. Other countries follow one of these two techniques, with exception for a 10

meter range (separation) measurement or a different range of test frequencies.

Each of the listed contacts will have resources to provide (for a fee) current regulations

and certification forms. They also can suggest sources for your formal tests, either

commercial labs or the government testing office. Unless you want to invest in a

qualified radiated signals test range, the commercial labs can help you with preliminary

measurements and some expertise in correcting any difficulties that are noted.

Contacts for further information and current test facilities listings:

ANSI

Institute of Electrical & Electronics Engineers,

345 East 47th Street, New York, NY 10017 USA

ETSI

European Telecommunications Standard Institute

F-06921 Sophia Antipolis Cedex FRANCE

FCC

Federal Communications Commission

Washington DC 20554 USA

Canada DOC

Industrie Canada

Attn: Certification, Engineering and Operations Section,

1241 Clyde Avenue, Ottawa K1A 0C8 CANADA

UNITED KINGDOM

LPRA (manufacturing association information)

Low Power Radio Association

The Old Vicarage, Haley Hill, Halifax HX3 6DR UK

Radiocommunications Agency (official)

Waterloo Bridge House, Waterloo Road

London SE1 8UA

JATE

Japan Approvals Institute (JATE)

Isomura Bldg, 1-1-3 Toranomon

Minato-ku Tokyo JAPAN

4 Virtual Wire® Development Kit Installation and Operation

4.1 Development Kit Assembly Instructions

Kit assembly includes the following steps:

• Install the antennas (or antenna cables) on the data radio boards

• Set the node address on the protocol boards

• Obtain and install AAA batteries in the protocol boards (power switch OFF)

• Plug the data radio boards onto the protocol boards

• Connect 9-Pin PC cables between the protocol boards and the host computers

• Install the terminal program in the host computers

• Configure the terminal programs and test the Virtual Wire communications link

Take care in plugging a transceiver board into a protocol board. The transceiver board

must be oriented so that THE BOARD RESTS ON THE NYLON SCREW SUPPORTS

AND NOT OVER THE BATTERIES. Be sure that the transceiver board pins are

correctly plugged into the protocol board connector. It is possible to plug the transceiver

board in so that a pin is hanging out on the left or right. BE SURE TO INSPECT THE

CONNECTOR ALIGNMENT BEFORE APPLYING POWER. Options and adjustments

are discussed below:

4.2 Data Radio Boards

The DR1200 Data Radio board is configured to operate at a data rate of 22.5 kbps on a

frequency of 916.50 MHz, and the DR1201 is configured to operate at 868.35 MHz. The

kits are shipped with a pair of data radio boards and matching antennas. Data Radio

boards with antennas can be purchased separately for development of applications.

Antenna Options- Antennas are supplied with the data radio boards that can simply be

soldered to the pad provided for the 50 ohm RF input (see the Drawings section of the

manual). These antennas are simple base-loaded monopoles. Alternatively, a 50 ohm

coaxial cable (RG-178, etc.) can be soldered to the RF input pad and the adjacent ground

pad(s), if a remotely located antenna is used. The remote antenna should have and

impedance of approximately 50 ohms, preferably with a VSWR of less than 2:1. A remote

antenna is necessary if the transceiver is housed inside a metal box, which is very

desirable if a noise source such as a high-speed microprocessor, high-speed logic or a

brush-type motor is mounted in close proximity to the transceiver board itself.

4.3 Protocol Board

Node Programming - The node address on each protocol board can be set from 1 to 15

by placing jumpers on the double row of pins located between the two IC’s. With no

jumpers, the node address is 1. Placing one jumper across the pins nearest to the

RS232 connector programs the board to address 2. The rule is that the node number is

the binary “jumper” value +1, with jumper pins closest to the RS232 connector being the

LSB position. The exception is jumpers on all pins, which is interpreted as node 1.

Node 0 is reserved for packets broadcasted to all other nodes. There is a node address

table in the Drawings section of the manual.

Power Supply - Each node can be operated from three 1.5 V AAA batteries.

RS232 Interface - Level conversion from CMOS to RS232 levels is provided by the

MAX 218 IC. It is possible to remove this IC and jumper socket Pin 7 to 14 and Pin 9 to

12 for direct CMOS operation.

LED Functions - Three LED indicators are provided on the protocol board. The LED

labeled RXI indicates RF signals are being received. The LED RF RCV indicates that a

valid RF packet has been received. The LED PC RCV indicates that a message has

been received from the PC.

4.4 Terminal Program

Installation - The terminal program is designed to operate under MS-DOS, version 5.0

or higher, on a PC equipped with an RS232 port on COM1 or COM2. To install the

terminal program, create a hard drive directory for the Virtual Wire application and

copy the files on the enclosed disk to the directory. After connecting the Virtual Wire

node to the computer and turning the node on, start the terminal program from within its

directory by typing VWT97V02.

Configuration - The configuration file, VWT97.CFG is provided with default values as

follows:

“COM1:””19200””2” (“com port number:””baud rate””TO node address”)

The configuration file can be edited from the terminal program. To edit from the terminal

program, use ALT-S. Note that one protocol board is addressed as node 1 and the

other is programmed as node 2 when received. As a minimum, the VWT97.CFG file will

have to be edited on at least one of the host computers before the Virtual Wire link

can be tested.

Operation - The following files are included on the terminal program disk:

VWT97V02.BAS QuickBASIC (DOS) Source File

VWT97V02.EXE Terminal Program Executable File

VWT97.CFG Terminal Program Configuration File (ASCII)

VWT97V02.TXT Terminal Program Notes (ASCII)

The program uses the following control keys:

Esc End task (transmit)

ALT-A Read Node Number

ALT-B Broadcast Mode

ALT-C Clear Screen

ALT-D Decrement TO Node Address

ALT-H Help Screen

ALT-I Increment TO Node Address

ALT-R Protocol Board Reset

ALT-S Configuration Set Up

ALT-T Protocol Board Self-Test

ALT-V Protocol Board Low Voltage Check

ALT-X Exit Program

CTL-N Software Reset of the Node Address

CTL-T Telemetry Mode (no ACK/NAK; both nodes must enable)

Function Key F1 Sends multi-packet test message

When VWT97V02.EXE begins running, the program looks for VWT97.CFG in the

current directory and obtains the COM port, baud rate and the TO node address for the

communications link. If VWT97.CFG is not present, the program requests configuration

information and builds VWT97.CFG. Pressing ALT-S will display configuration

information and allow real-time configuration editing. After reading or building the

configuration file, the program gets the FROM node address from the protocol board

and enters the terminal mode (…UNIT NOT RESPONDING… message displayed if

protocol board does not respond). The terminal mode screen includes three windows.

The top window is the MESSAGES RECEIVED window, and displays packets sent to

the local node. The bottom window is the ENTER MESSAGE TO SEND window, where

messages to be sent are input. A blinking cursor of the form “_” is provided.

VWT97V02.EXE supports “plain text” ASCII messages.

The middle window is the MESSAGES SENT window, which shows message packets

as sent (SOT [02h] and EOT [03h] symbols displayed as “J” and “♥”), the packet

number, and the packet status. This window gives a real time depiction of how

messages are packetized and sent. Message PACKET# is 1-7 (recycling). Packet

STATUS is RX OK ON n (n is the retry number 1-8) for acknowledged packets.

From the keyboard, the user may enter text up to 79 characters per message. The

Backspace Key allows for character erasures and corrections, and the Delete Key

erases all characters entered but not transmitted. Pressing the Enter Key terminates

the message input and starts packetizing and transferring the message to the protocol

board via the serial port. Also, when 79 characters are input, message is automatically

sent.

If the Enter Key is pressed as the first keyboard action after starting the terminal

program, the default message is:

**Virtual Wire RF Link Test**

A received message is displayed on a single line in the MESSAGES RECEIVED

window, whether it is made up of one or more packets. When the whole message is

received, it is displayed. If a multi-packet message is partially received and then the first

packet of new message is received, the partial message is discarded and reception of

the new message is begun.

When text reaches the bottom of the MESSAGES RECEIVED or the MESSAGES

SENT window, the text will scroll until ALT-C is invoked to clear all windows. When 79

characters are input or the Enter Key is pressed in the ENTER MESSAGE TO SEND

window, this window is cleared and the cursor moves back to the left side of the

window.

In the event that the link between the PC and the protocol board is lost (low batteries,

ON/OFF switch off, no cable, etc.) a TIME OUT - VW UNIT NOT RESPONDING alarm

message will be displayed. If a packet is unacknowledged after eight tries, a LINK

FAULT message will be displayed in the STATUS column of the MESSAGES SENT

window.

There are many other possible ways to interact with the Virtual Wire Link Layer

Protocol. The main purposes of the VWT97V02 terminal program is to demonstrate

software handshaking with the protocol and to support initial Development Kit testing.

Check RFM’s Internet web site, www.rfm.com, for additional Development Kit software

and software application notes.

5 Theory of Operation

5.1 Data Radio Boards

I/O Interface- Referring to the Data Radio Board schematic diagram, connector P1 is the

interface connector to the protocol board. Pin 1 is the transmitter data input and can be

driven directly by a CMOS gate. The transmitter is pulse ON-OFF modulated by a signal

on this line changing from 0 to 3 volts. A high level turns the transmitter oscillator on and a

low level turns it off. The input impedance to this line is approximately 27 kilohms. Pin 2 is

a Vcc line for the TR1000/TR1001 ASH transceiver.

Pin 3 is the PTT line that enables the transmit mode. This line puts the TR1000 (or

TR1001) in the transmit mode when it is high (2.5 volts minimum at 2.0 mA maximum).

Pin 4 is a Vcc line connected in parallel with Pin 2. Pin 5 is ground. Pin 6 is unused. Pin 7

is a Vcc line, connected in parallel with Pin 2 and Pin 4. Pin 8 the data output pin from the

transceiver. This data output is CMOS compatible and is capable of driving a single

CMOS gate or a bipolar transistor with a 51 K base resistor. The last connection to the

data radio board is the 50 ohm antenna input. The antenna can either be connected

directly to the board or connected remotely by using a 50 ohm coaxial cable.

TR1000/TR1001 ASH Transceiver - The heart of the DR1200 Data Radio board is the

TR1000 ASH transceiver (DR1201 uses the TR1001). This miniature ceramic-metal

hybrid provides a bilateral digital signal to RF signal communication capability. The

following section provides an introduction to the ASH transceiver’s features, capabilities,

theory of operation and configurability:

ASH Transceiver Features

• Designed for short-range wireless packet data communications

• Supports RF data rates up to 115.2 kbps

• 3 V, low current operation with integrated power down function

• Stable, easy to use, with all critical RF functions contained in the hybrid

• Robust receiver performance with full sensitivity up to 1 GHz

• Highly configurable with a minimum of external parts

• Choice of OOK or ASK transmitter modulation

• Rugged, miniature ceramic-metal package

• Low implementation cost

• Easy certification to FCC, ETSI and similar low-power radio regulations

RFM’s amplifier-sequenced hybrid (ASH) transceivers are ideal for short-range wireless

data communications where small size, low power consumption and low cost are

required. All critical RF functions are contained in the hybrid, simplifying and speeding

design-in. The receiver section is sensitive and stable. Two stages of SAW filtering

provide excellent receiver out-of-band rejection. The transmitter includes provisions for

on-off keyed (OOK) or amplitude-shift keyed (ASK) modulation. The transmitter

employs SAW filtering to suppress output harmonics, facilitating compliance with FCC

15.249, ETSI I-ETS 300 220-1 and similar low-power radio regulations.

ASH transceiver technology offers a rich set of enabling features in short-range wireless

applications. Key features include:

• Small size - the ASH transceiver package footprint is nominally 0.28 x 0.40 inch,

with a package volume of only 0.009 in3 (146 mm3). Transceiver operating is

configured using a dozen miniature passive components, making is practical to add

short-range wireless data connectivity to a watch, pen, PDA or shirt pocket PCS

phone.

• Low power - the ASH transceiver operates from 3 Vdc, drawing only 6 mA average

in transmit and 1.8 to 7.5 mA in receive (set-up dependent). In addition, the

transceiver has an integrated power-down mode to support long duration operation

from small batteries.

• Robust operation - the ASH transceiver is a single-channel data radio, employing

amplitude-shift keyed modulation. But unlike simple AM systems, extensive

consideration has been given to operating robustness in the transceiver

architecture. The receiver chain includes a narrow-band SAW filter and a SAW

delay line, which together provide excellent out-of-band rejection. The logarithmic

receiver detector features more than 70 dB of dynamic range. This is combined with

30 dB of AGC, providing 100 dB of overall receiver dynamic range. Data is

recovered from the detected base-band signal using a compound data slicer which

provides both excellent threshold sensitivity for low-level signals and good rejection

of interference 8-10 dB below the peak level of stronger desired signals. Operating

robustness is inherent in the signal processing of the radio itself, providing

considerable flexibility in the choice of data protocols that can be used with the

transceiver.

ASH Transceiver Operation

The ASH transceiver’s unique feature set is made possible by its system architecture.

The heart of the transceiver is the amplifier-sequenced receiver section, which provides

over 90 dB of stable RF and detector gain without any special shielding or decoupling

provisions. Stability is achieved by distributing the total RF gain over time. This is in

contrast to a superheterodyne receiver, which achieves stability by distributing total RF

gain over multiple frequencies.

Refer to the Block Diagram and Timing Cycle drawing in Section A of the manual for

the following discussion. This drawing shows the basic amplifier-sequenced receiver

architecture. Note that the bias to RF amplifiers RFA1 and RFA2 are independently

controlled by a pulse generator, and that the two amplifiers are coupled by a surface

acoustic wave (SAW) delay line, which has a typical delay of 0.5 µs.

An incoming RF signal is first filtered by a narrow-band SAW filter, and is then applied

to RFA1. The pulse generator turns RFA1 ON for 0.5 µs. The amplified signal from

RFA1 emerges from the SAW delay line at the input to RFA2. RFA1 is now switched

OFF and RFA2 is switched ON for 0.55 µs, amplifying the RF signal further. The ON

time for RFA2 is usually set at 1.1 times the ON time for RFA1, as the filtering effect of

the SAW delay line stretches the signal pulse from RFA1 somewhat. As shown in the

timing diagram, RFA1 and RFA2 are never on at the same time, assuring excellent

receiver stability. Note that the SAW filter and delay line act together to provide very

high receiver ultimate rejection.

Amplifier-sequenced receiver operation has several interesting characteristics that can

be exploited in system design. The RF amplifiers in an amplifier-sequenced receiver

can be turned on and off almost instantly, allowing for very quick power-down (sleep)

and wake-up times. Also, both RF amplifiers can be off between ON sequences to

trade-off receiver noise figure for lower average current consumption. The effect on

noise figure can be modeled as if RFA1 is on continuously, with an attenuator placed in

front of it with a loss equivalent to 10*log10(RFA1 duty factor), where the duty factor is

the average amount of time RFA1 is ON (up to 50%).

Please refer to the ASH Transceiver Block Diagram in Section A for the following

discussion:

Antenna port - the only external RF components needed for the ASH transceiver are

the antenna, antenna matching coil and electrostatic discharge (ESD) protection choke.

Receiver chain - the narrow-band SAW filters provides high receiver RF selectivity. The

output of the SAW filter drives amplifier RFA1. This amplifier includes provisions for

detecting the onset of saturation (AGC Set), and for switching between 35 dB of gain

and 5 dB of gain (Gain Select). AGC Set is an input to the AGC Control function, and

Gain Select is the AGC Control function output. ON/OFF control to RFA1 (and RFA2) is

generated by the Pulse Generator & RF Amp Bias function. The output of RFA1 drives

the low-loss SAW delay line, which has a nominal delay of 0.5 µs. Note that the SAW

RF filter and SAW delay line both contribute to the excellent out-of-band rejection of the

receiver.

The second amplifier, RFA2, provides 51 dB of gain below saturation. The output of

RFA2 drives a square-law detector with 19 dB of threshold gain. The onset of saturation

in each section of RFA2 is detected and summed to provide a logarithmic response.

This is added to the output of the square-law detector to produce an overall detector

response that is square law for low signal levels, and transitions into a log response for

high signal levels. This combination provides excellent threshold sensitivity and more

than 70 dB of detector dynamic range. In combination with the 30 dB of AGC range in

RFA1, more than 100 dB of receiver dynamic range is achieved.

The detector output drives a three-pole, 0.05 degree equiripple low-pass filter response

with excellent group delay flatness and minimal pulse ringing. The 3 dB bandwidth of

the filter is adjusted with a single external resistor to match the data rate and data

encoding of the transmitted signal.

The filter is followed by a base-band amplifier which boosts the detected signal to the

BBOUT pin, which is coupled to the CMPIN pin or to an external data recovery process

(DSP, etc.) by a series capacitor.

When the transceiver is placed in power-down or in a transmit mode, the output

impedance of BBOUT becomes very high. This feature helps preserve the charge on

the coupling capacitor to minimize data slicer stabilization time when the transceiver

switches back to the receive mode.

Data Slicers - The CMPIN pin drives two data slicers, which convert the analog signal

from BBOUT back into a data stream. The best data slicer choice depends on the

system operating parameters. Data slicer DS1 is a capacitor-coupled comparator with

provisions for an adjustable threshold. DS1 provides the best performance at low

signal-to-noise conditions. The threshold, or squelch, offsets the comparator’s slicing

level, and is set with a resistor between the RREF and THLD1 pins. This threshold

allows a trade-off between receiver sensitivity and output noise density in the no-signal

condition. S2 is a “dB-below-peak” slicer. The peak detector charges rapidly to the peak

value of each data pulse, and decays slowly in between data pulses (1:1000 ratio). The

slicer trip point can be set from 0 to 12 dB below this peak value with a resistor between

RREF and THLD2. DS2 is best for ASK modulation where the transmitted signal has

been shaped to minimize signal bandwidth.

AGC Control - The output of the Peak Detector also provides an AGC Reset signal to

the AGC Control function through the AGC comparator. The purpose of the AGC

function is to extend the dynamic range of the receiver, so that two transceivers can

operate close together when running ASK and/or high data rate modulation. The AGC

also prevents receiver saturation by a strong in-band interfering signal, allowing

operation to continue at short range in the presence of the interference. The onset of

saturation in the output stage of RFA1 is detected and generates the AGC Set signal to

the AGC Control function. The AGC Control function then selects the 5 dB gain mode

for RFA1. The AGC comparator will send a reset signal when the Peak Detector output

(multiplied by 0.8) falls below the fixed reference voltage for DS1. A capacitor at the

AGCCAP pin avoids AGC “chattering” during the time the signal propagates through the

log detector, low-pass filter and charges the peak detector. The AGC capacitor also

allows the AGC hold-in time to be set longer than the peak detector decay time to avoid

AGC chattering during runs of “0” bits in the received data stream. Note that AGC

operation requires the peak detector to be functioning, even if DS2 is not used. AGC

operation can be defeated by connecting the AGCCAP pin to VCC, or latched ON

connecting a resistor between the AGCCAP pin and ground.

Receiver pulse generator and RF amplifier bias - The receiver amplifier-sequence

operation is controlled by the Pulse Generator & RF Amplifier Bias module, which in

turn is controlled by the PRATE and PWIDTH input pins, and the Power Down Control

Signal from the Modulation & Bias Control function.

Transmitter chain - the transmitter chain consists of a SAW delay line oscillator TXA1,

followed by a modulated buffer amplifier TXA2. The SAW filter suppresses transmitter

harmonics to the antenna. Note that the same SAW devices used in the amplifier-

sequenced receiver are reused in the transmit modes. A resistor is used to provide

decoupling between the RF VCC and the power amplifier Vcc. (See R18 on the

DR1200 schematic diagram.)

Transmitter operation supports two modulation formats, on-off keyed (OOK)

modulation, and amplitude-shift keyed (ASK) modulation. When OOK modulation is

chosen, the transmitter output turns completely off between “1” data pulses. When ASK

modulation is chosen, a “1” pulse is represented by a higher transmitted power level,

and a “0” is represented by a lower transmitted power level. OOK modulation provides

compatibility with first-generation ASH technology, and provides for power conservation.

ASK modulation must be used for high data rates (data pulses less than 30 µs). ASK

modulation also reduces the effects of some types of interference and allows the

transmitted pulses to be shaped to control modulation bandwidth. The transmitter RF

output voltage is proportional to the input current to the TXMOD pin, which modulates

TXA2. A resistor in series with TXMOD adjusts the peak transmitter output power.

The four transceiver operating modes - receive, transmit ASK, transmit OOK and

power-down (“sleep”), are controlled by the Modulation & Bias Control function, and are

selected with the CNTRL1 and CNTRL0 control pins. CNTRL1 and CNTRL0 are CMOS

compatible inputs.

ASH Transceiver Configurability

ASH transceivers are highly configurable, offering the user great flexibility in optimizing

for specific applications and protocol formats. The operating configuration is set using

low-cost resistors and capacitors. Key points of configurability include:

• Adjustable receiver sensitivity versus current consumption

• Adjustable receiver low-pass filter to support various data rates/encoding techniques

• Adjustable peak transmitter output power

• Conventional or “dB below peak” data slicer select

• Adjustable thresholds (squelch settings) for each data slicer

• Adjustable AGC hold-in time and AGC latch/defeat function

• OOK or ASK modulation with adjustable ASK modulation depth

• Continuous or duty-cycled operation (integrated power down function)

• 2.7 to 3.5 Vdc power supply range (down to 2.2 Vdc over limited temperature range)

Data Radio Board Specifications

Operating Frequency

DR1200 916.5 MHz

DR1201 868.35 MHz

Modulation On-Off Keyed

Antenna 50 ohm

Operating Data Rate 22.5 kbps (44.4 µs min. pulse width @ TX input)

TX Frequency Tolerance less than ±200 kHz, including set-on, temperature

and aging drift (5 year)

TX Output Power -6 dBm nominal

TX Harmonics less than -32 dBc

Receiver Performance BER less than 10E-4 for a -85 dBm input (22.5 kbps)

RX Pulse Distortion less than ±25% for a 44.4 µs TX pulse

RX Dynamic Range -85 to -10 dBm

Data DC Balance receiver performance shall be maintained for

data with an average “1” density from 45 to 55%

Data Run Length receiver performance shall be maintained for

“1” or “0” run lengths of at least 6 bits

RX Off-Channel Rejection

DR1200-DK greater than 60 dB, 0.25 to 890 MHz and

945 to 2500 MHz

DR1200-DK greater than 60 dB, 0.25 to 842 MHz and

897 to 2500 MHz

RX On-Channel Rejection less than 30% BER degradation for an interfering

signal at least 15 dB below the desired signal after 16

bits (50% duty cycle) of the desired signal received

RX No-Signal Output less than one noise “spike” average in any 10 ms

interval under “white thermal noise” reception

conditions

Transceiver Mode Change

RX to TX 10 µs

TX to RX 78 µs

DC Power Supply 2.7 to 3.5 Vdc, 10 mV max peak-to-peak ripple

Supply Current, RX Mode less than 4.0 mA ave @ 3 Vdc supply

Supply Current, TX Mode less than 12 mA peak @ 3 Vdc supply

I/O Data Interface 3 V CMOS logic level for serial TX input; serial RX

output capable of driving one 3 V CMOS gate

TX/RX Control Input low for RX, high for TX (source 2 mA @ 2.5 V min.)

Operating Temperature Range -40 to +85 deg C

5.2 Protocol Board

I/O Interface - Connector J1 (see Protocol Board schematic) is the I/O interface

between the protocol board and the data radio board. J1-Pin 1 carries the transmit data

signal from U2-Pin 7 to the transmitter input on the Data Radio board. J1-Pin 2 provides

Vcc to the Data Radio board. J1-Pin 3 provides the transmit enable signal (PTT) from

PNP transistor Q2. The Data Radio board requires 2 mA at 2.5 V on the PTT input to

enable the transmit mode. J1-Pin 7 is another Vcc input to the Data Radio board. J1-

Pin 5 is ground. J1-Pin 4 is a third Vcc input to the Data Radio board. J1-Pin 8 carries

the receiver digital output from the Data Radio board. Q1 provides a high input

impedance buffer between this signal and the input to U2. J1-Pin 6 is unused in the

DR1200-DK and DR1201-DK implementation.

RS232 Interface - Connector J2 is the RS232 interface on the protocol board. This

9-Pin female connector is configured to appear as a DCE (modem). The protocol board

implements software flow control, so only J2-Pin 2 and J2-Pin 3 carry active signals.

J2-Pin 2 (RD) sends data to the host computer, and J2-Pin 3 receives data from the

host computer (TD). J2 Pins 4 and 6 are connected (DTR & DSR), and J2 Pins 1,7 and

8 are connected (CD, RQS, CTS) J2-Pin 5 is ground.

Protocol Microcontroller - The link-layer protocol is implemented in an ATMEL

AT89C2051 microcontroller U2. The 8-bit microcontroller operates from an 22.118 MHz

quartz crystal. The microcontroller includes 2 Kbytes of flash EPROM memory and 128

bytes of RAM. The microcontroller also includes two 16-bit timers and one hardware

serial port, making it especially suitable as a link-layer packet controller. The timers,

serial port and input interrupts remain active while the processor is in the power-saving

idle mode, allowing the link-layer protocol to be implemented on a low average current

budget.

Inputs to the microcontroller include the node programming pins ID0 - ID3, on Pins 14,

15, 16 and 17, the buffered receive data (RRX) on Pin 6, the CMOS-level input from

the host computer on Pin 2. Outputs from the microcontroller include the transmit data

on Pin 7, the data output to the host computer on Pin 3, the transmit enable signal Pin

19, the RS232-transceiver control on Pin 18, and the LED outputs on Pins 8 (RXI), 9

(RF RCV), and 11(PC RCV). Diode D2 and capacitor C7 form the power-up reset circuit

for the microcontroller.

CMOS/RS232 Level Converter - Conversion to and from RS232 and 4.5 V CMOS logic

levels is done by U1, a Maxim MAX218 Dual RS232 Transceiver. The operation of the

MAX218 is controlled by microcontroller U2, to minimize average current consumption.

L1, D1 and C5 operate in conjunction with the IC’s switch-mode power supply to

generate ±6.5 V for the transmitter and receiver conversions. Pin 3 on the MAX218

controls the switched-mode supply via U2 Pin 18. The RS232 serial input signal from

J2-Pin 3 is input on U1-Pin 12 and is converted to a 4.5 V CMOS level (note inversion)

and output on U1-Pin 9. The CMOS serial output signal from U2-Pin 2 is input on U1-

Pin 7 and converted to an RS232 output (note inversion) on U1-Pin 14. This signal is

found on J2-Pin 3.

The RS232 conversion can be bypassed for direct CMOS operation by removing U1

from its socket and placing one jumper in socket Pins 7 and 14 and a second jumper in

socket Pins 9 and 12.

Protocol Board Specifications

Host Interface RS232 DCE compatible 9-Pin female

(modem) connector, 19.2 kbps, byte asynchronous,

1 start bit, 8 data bits, no parity, 1 stop bit

Radio Interface RFM Data Radio Type-1 interface, 8-Pin

SIP connector, 22.5 kbps, 12 DC-balanced symbol

bits/byte, with integrated PTT control

Power Supply 4.5 Vdc nominal from 3 AAA batteries

Operating Temperature Range 0 to 70 deg C

Storage Temperature Range -40 to +85 deg C

5.3 Protocol Firmware

Description - The purpose of this data-link protocol is to provide automatic, verified,

error-free transmission of messages between Virtual Wire® Radio Nodes via RS232

serial connections to the host processors. Operation on both the RS232 side and the

radio side is half-duplex.

Operation of the RS232 serial connection is 19.2 kbps, with eight data bits (byte), one

stop bit, and no parity bit. The transmission rate on the radio side is approximately

22.5 kbps, using 12-bit DC-balanced symbols for each data byte. The radio receiver is

slightly “squelched” when not receiving data, and will output occasional random positive

noise spikes.

The following I/O lines are implemented on the protocol microcontroller:

radio receive line (RRX)

radio transmit line (RTX)

radio transmit/receive control line, high on transmit (PTT)

RS232 receive line (PRX)

RS232 transmit line (PTX)

Maxim 218 ON/OFF control line

node ID input lines (ID0 through ID3)

three LED control Lines (RXI, RF RCV and PC RCV)

The link-layer protocol is capable of transmitting/receiving binary data bytes of any bit

pattern. Messages are sent and received from the RS232 interface in standard

asynchronous format via PTX and PRX. The first byte of the RS232-side messages

contain a “TO/FROM” address, with the high nibble the “TO” node ID, and the low

nibble the “FROM” node ID. The second byte is the message sequence number (1-7

recycling or 8 used for telemetry packets), the third byte is the number of data bytes in

the message (up to 20 hex), followed by the data bytes. A single message can contain

up to 32 data bytes, with 16 to 24 data bytes typical.

The protocol software continually tests the RRX line and the PRX line, searching for a

start bit. When a start bit is detected on one of the input lines, the software will attempt

to receive a message on that input line. If an error is detected in the message, it will be

discarded and the software will resume testing the input lines.

If a valid message is received on the PRX input line, the software will format a radio

packet from the message and queue the packet for transmission. The packet format

shall include a start symbol (22 hex), the TO/FROM byte, the message number, the

number of data bytes in the message, the data bytes, and a 16 bit error detection

“frame check sequence” (FCS). The FCS is calculated based on all bits in the message

following the start symbol. The FCS as defined by ISO 3309 is used.

Each byte transmitted by the radio is converted into a 12 bit, dc-balanced symbol. DC

balance “trains” the receiver data slicer for best noise immunity by setting the threshold

half way between a “1” and “0” value. The dc-balanced symbols used have no more

than 3 bits of the same value in a row. This limited “run length” allows the receiver data

slicer to be tuned to recover quickly from a heavy noise burst or strong interfering

signal.

The queued packet is transmitted (RTX line with PTT invoked), and the software then

looks for a “packet received” acknowledgment (RRX line). An acknowledgment packet

includes the start byte, the TO/FROM byte, the packet number being acknowledged,

hex En (n is the retry number correctly received) and the FCS. When an

acknowledgment is received for the queued packet, an acknowledgment message

(packet less start symbol and FCS) is sent on the PTX line, the packet is discarded, and

the software resumes testing the input lines. If a packet acknowledgment is not

received in 120 ms, the packet is resent after a randomly selected delay of

(approximately) 0 , 120, 240 or 360 ms. If the packet is not acknowledged after a total

of eight tries, the software will send a “NAK” message on the PTX line (TO/FROM

address, packet number and hex DD), discard the packet, and resume testing the input

lines.

When a start symbol is detected on the RRX line, the software will attempt to receive

and verify a message by checking for a correct TO/FROM address, a valid packet

sequence number, a valid number of data bytes (or “ACK” character), and a correct

FCS calculation. If the packet is verified and the “TO” nibble matches, the TO/FROM

address, packet sequence number, number of data bytes and the data bytes of the

message are sent out on the PTX line and a packet acknowledgment is transmitted

back on the RTX line. Otherwise, the message is discarded and testing of the input

lines is resumed. The software will accept message packets and acknowledgment

packets in any sequence. If an acknowledged packet is received a second time (based

on the current value of the message sequence counter) it is reacknowledged on RTX

but not retransmitted on PTX.

The TO/FROM address of 00h is treated as a “broadcast” packet. In this case, a

received packet is sent out on the PTX line if the number of data bytes are in a valid

range and the FCS calculation matches. In the broadcast mode, the packet is

transmitted eight times to enhance probability or reception. A broadcast packet is not

acknowledged by the receiving node(s). A packet with a packet number of 8 is treated

as a telemetry packet. If the TO address matches the local node number and the

number of bytes and FCS is valid, it placed on the PTX, but is not acknowledged.

If a start bit is detected on either RRX or PRX, the software receives and acts on the

information on that input line, and does not service the other input line until it has

received and acted on the data from the first input line. Host software must implement a

simple transmit message software flow control to accommodate this characteristic.

When the host software is ready to send a message to the protocol software, it tests

the availability of the PRX interrupt by sending just the TO/FROM address character to

the protocol board. If this TO/FROM address is echoed back within 50 ms, it has control

of the PRX interrupt process and can send the rest of the message in the following

200 ms. If a character is input with the high nibble equal to the local node address (or

the byte equal to 00h for a broadcast packet) within the 50 ms window, it could be an

inbound message for the local node, and the rest of the message should be received

and tested to see if it is a valid message. If no character is echoed in the 50 ms

following the TO/FROM character transmission, the protocol board can be assumed

busy on an RRX interrupt either receiving a packet or tripped by receiver output noise.

The host program should retry. An inbound packet can occur at any time, so any

character with the high nibble equal to the local node address or any 00h byte should

be processed to test for a valid message. In addition to packet messages, special

messages are provided, such as “Run Self Test”. Special message formats are given

below.

Protocol-Host Message Formats

General Message Format:

Note: the Size/Status byte indicates the number of bytes in the message (up to

20h), or a status message (e.g., ACK = 0Enh, NAK = 0DDh, etc.) Packet # 08h

indicates a telemetry packet. A TO address of 0h indicates a broadcast packet.

Link Status Messages:

ACK | TO/FROM | Packet # | En | (n = 1 to 8)

NAK | TO/FROM | Packet # | DD |

Special Messages from the Host to the Protocol:

Reset: | FROM/FROM | 00h | 01h | 30h |

Send Node Address: | 00h | 00h | 01h | 31h |

Set Node Address: | 00h | 00h | 01h | 34h |

Run Self Test: | FROM/FROM | 00h | 01h | 33h |

Special Messages from the Protocol to the Host:

Message from Host too Long: | FROM/FROM | 00h |01h | 30h |

Failed Self Test: | FROM/FROM | 00h | 01h | 33h |

Passed Self Test: | FROM/FROM | 00h | 01h | 34h |

Local Node Address: | FROM/FROM | 00h | 01 | 35h |

where FROM/FROM is the local address

5.4 Terminal Program

Description - VWT97V02.EXE is a compiled QuickBASIC (4.5) program that

demonstrates interaction with the Virtual Wire Protocol. The commented source code

listing is provided below for reference. Be sure to check RFM’s Internet web site -

www.rfm.com for new software updates. Note: This terminal program does not include

provisions for automatic compliance with the duty-cycle requirements of the new ETSI

I-ETS 300 220-1 regulations for the 868.00 - 868.60 MHz band (DR1201-DK). Limiting

the duty-cycle in the final application software will be required for ETSI certification. At

the time this manual is was written, the proposed duty cycle limit was seconds per hour,

but this may change in the final release of the specification. Be sure to check the final

version of the regulation before completing product development.

Source Code Listing-

'VWT97V02.BAS VWDK TERMINAL PROGRAM, Copyright RF Monolithics, Inc., 1996, 1997

'REV 04-15-97 ADDED MULTIPLE BAUD RATE SUPPORT

'REV 04-25-97 MISC SCREEN CLEAN UPS

'REV 05-06-97 ADDED "TO ADDRESS" ALERT MESSAGE

'REV 05-10-97 GENERAL CLEAN UPS

'REV 05-15-97 VWT97V01 FIRST RELEASE

'REV 11-14-98 VWT97V02 TUNED FOR DR12xx-DK ASH TRANSCEIVER DEVELOPMENT KITS

'Check www.rfm.com for the latest VWDK SW updates

DEFINT A-Z: OPTION BASE 1

DIM MINI.MSG$(100)

'THE SPECIAL MESSAGE FORMAT IS THE SAME TO AND FROM THE VIRTUAL WIRE UNIT.

' " " " = | F/F | 0 | 1 |SPECIAL MSG. |

'NOTE T/F = F/F SINCE MESSAGE IS NOT FOR ANY OTHER UNITS.

'-------------- SPECIAL MESSAGES FROM VIRTUAL WIRE UNIT TO PC -------------

MSG.FROM.VW$ = CHR$(&H0) 'NULL = UNKNOWN MESSAGE WAS RECEIVED

MSG0.FROM.VW$ = "0" '(&H30) MESSAGE PACKET i.e. NUMBER BYTES TOO LONG

MSG1.FROM.VW$ = "1" '(&H31) LOW BATTERY

MSG2.FROM.VW$ = "2" 'BATTERY VOLTAGE OK

MSG3.FROM.VW$ = "3" 'FAILED SELF TEST

MSG4.FROM.VW$ = "4" 'PASSED SELF TEST

MSG5.FROM.VW$ = "5" 'TO/FROM (T/F) = F/F = VIRTUAL WIRE UNIT ADDRESS

'--------------- SPECIAL MESSAGES TO VW UNIT FROM PC ----------------------

MSG0.TO.VW$ = "0" 'RESET VW UNIT

MSG1.TO.VW$ = "1" 'SEND ADDRESS

MSG2.TO.VW$ = "2" 'TEST BATTERY AND RETURN RESULTS

MSG3.TO.VW$ = "3" 'RUN SELF TEST

MSG4.TO.VW$ = "4" 'CHANGE NODE ADDR.

VW.ACK$ = CHR$(&HEE) 'VIRTUAL WIRE "ACK"

VW.NAK$ = CHR$(&HDD) 'VIRTUAL WIRE "NAK"

FULL.MSG$ = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789ABCD "

'****************************************************************************

F1$ = CHR$(0) + CHR$(59) 'FUNCTION KEY F1

F2$ = CHR$(0) + CHR$(60)

F3$ = CHR$(0) + CHR$(61)

F4$ = CHR$(0) + CHR$(62)

F5$ = CHR$(0) + CHR$(63)

F6$ = CHR$(0) + CHR$(64)

F7$ = CHR$(0) + CHR$(65)

F8$ = CHR$(0) + CHR$(66)

F9$ = CHR$(0) + CHR$(67)

F10$ = CHR$(0) + CHR$(68)

UP$ = CHR$(0) + CHR$(72) '^

DWN$ = CHR$(0) + CHR$(80) 'v

LFT$ = CHR$(0) + CHR$(75) '<

RT$ = CHR$(0) + CHR$(77) '>

DEL$ = CHR$(0) + CHR$(83) 'DELETE KEY

BACK$ = CHR$(8) 'BACK SPACE

ESC$ = CHR$(27) 'ESCAPE

CR$ = CHR$(13) 'RETURN /ENTER KEY CODE

BLANK$ = CHR$(&H20) 'SPACE CHARACTER

PGUP$ = CHR$(0) + CHR$(&H49) 'PAGE UP

PGDN$ = CHR$(0) + CHR$(&H51) 'PAGE DOWN

TAB$ = CHR$(9)

SHIFT.TAB$ = CHR$(0) + CHR$(&HF)

ALT.C$ = CHR$(0) + CHR$(46)

ALT.S$ = CHR$(0) + CHR$(31)

ALT.X$ = CHR$(0) + CHR$(45)

ALT.A$ = CHR$(0) + CHR$(30)

ALT.H$ = CHR$(0) + CHR$(35)

ALT.I$ = CHR$(0) + CHR$(23)

ALT.V$ = CHR$(0) + CHR$(47)

ALT.T$ = CHR$(0) + CHR$(20)

ALT.D$ = CHR$(0) + CHR$(32)

ALT.B$ = CHR$(0) + CHR$(48)

ALT.R$ = CHR$(0) + CHR$(19)

CTRL.T$ = CHR$(20)

CTRL.N$ = CHR$(14)

'COMM. CONTROL CHARACTERS

SOH$ = CHR$(1) 'START OF HEADER

STX$ = CHR$(2) 'START OF TEXT - START OF XMISSION

ETX$ = CHR$(3) 'END OF TEXT - END OF XMISSION

EOT$ = CHR$(4) 'END OF TRANSMISSION

ETB$ = CHR$(&H17) 'END OF BLOCK - LAST DATA BYTE 0 - 16

NAK$ = CHR$(&H15) 'NEGATIVE ACKNOWLEDGE - CHECK SUM NO COMPUTE

ACK$ = CHR$(6) 'ACKNOWLEDGE - CHECK SUM OK

RCV.PTRX = 1 'POINTER FOR RECEIVE WINDOW

RCV.PTRY = 5

LAST.MSG$ = "**Virtual Wire RF Link Test**" 'tweaked 97.05.10

Packet = 1

TO.ADDR = 2 'DEFAULT

TO.ADDR$ = "2" 'DEFAULT added 97.05.10

COM.PORT$ = "COM2:" 'DEFAULT

BAUD.RATE$ = "4800" 'DEFAULT

ON ERROR GOTO PRTERRO 'set up error handler (files, com port, etc.)

GOSUB SETUP.DSK 'read/build/save configuration files to disk 97.05.10

OPEN COM.PORT$ + BAUD.RATE$ + ",N,8,1,RS,CD0,DS0,CS0" FOR RANDOM AS #1 LEN = 2048

CLS

GOSUB GET.ADDRESS

GOSUB TOADDR.MSG 'added 97.05.10

MAIN:

COLOR 7, 0 'Ensure screen state 97.05.10

RCV.PTRX = 1 'POINTER FOR RECEIVE WINDOW

RCV.PTRY = 5

GOSUB SCREEN1

IF LOC(1) > 0 THEN

DATAB$ = INPUT$(LOC(1), #1) 'CLEAR COMM. BUFFER

ELSE

END IF

DATAB$ = ""

'*************************** EDIT MESSAGE ******************************

MINI.WORD:

ERASE MINI.MSG$ 'MESSAGE FOR SENDING TO VW UNIT

LOCATE 23, 1, 1, 5, 7

MINI:

IF BUSY = 0 AND NUMBER.TO.SEND > 0 THEN

GOSUB SEND.PACKET

ELSE

END IF

'--------------------CHECK COMM. BUFFER ----------------------------------

IF LOC(1) > 0 THEN 'KEEP LOOKING FOR COMMUNICATIONS

GOSUB READ.BUFFER

IF BUSY > 0 THEN 'SEE IF IT IS RESPONSE TO LAST PACKET

IF LEN(DATAB$) = 3 THEN 'LENGTH CORRECT FOR VW.ACK OR VW.NAK

IF ASC(MID$(DATAB$, 2, 1)) = Packet THEN 'CORRECT RESPONSE

Packet = Packet + 1

IF Packet = 8 THEN

Packet = 1

ELSE

END IF

'----- VW.ACK$ &HEn n = 1 to 9

IF RIGHT$(DATAB$, 1) >= CHR$(&HE1) AND RIGHT$(DATAB$, 1) <= CHR$(&HE9) THEN

RMSG$ = "RX OK ON " + CHR$((ASC(RIGHT$(DATAB$, 1)) - &HE0) OR &H30)

ELSEIF RIGHT$(DATAB$, 1) = CHR$(&HEE) THEN 'For compatibility with VWT.BAS (4-25-

97)

RMSG$ = "RX OK"

ELSEIF RIGHT$(DATAB$, 1) = VW.NAK$ THEN

IF BROADCAST = 1 THEN

RMSG$ = "BROADCAST FINISHED"

ELSE

IF (ASC(LEFT$(DATAB$, 1)) AND &HF) = TO.ADDR THEN

'-ATMEL DOES NOT SEND "NAK" BUT COULD IN FUTURE

RMSG$ = "RF LINK FAULT (REMOTE)" 'tweaked 97.05.10

ELSEIF (ASC(LEFT$(DATAB$, 1)) AND &HF0) / 16 = TO.ADDR THEN

RMSG$ = "RF LINK FAULT" 'NO RESPONSE TIME OUT - tweaked 97.05.10

ELSE

END IF

BEEP

BUSY = 0 'IF LINK FAULT THEN STOP SENDING

NUMBER.TO.SEND = 0

ELSE

RMSG$ = ""

END IF

DATAB$ = ""

'--- PUT MESSAGE ON DISPLAY

IF RMSG$ <> "" THEN

SELECT CASE PACKET.PTR

CASE 1

LOCATE 16, 62, 0

PRINT RMSG$;

CASE 2

LOCATE 17, 62, 0

PRINT RMSG$;

CASE 3

LOCATE 18, 62, 0

PRINT RMSG$;

CASE ELSE

END SELECT

BUSY = 0

PACKET.PTR = PACKET.PTR + 1

IF PACKET.PTR > NUMBER.TO.SEND THEN 'LAST PACKET SENT

PACKET.PTR = 1

NUMBER.TO.SEND = 0

GOSUB CLEAR.W3

COLOR 0, 7

LOCATE 23, 1, 1, 5, 7

ELSE

END IF

ELSE

END IF

ELSE

'WRONG PACKET# ERROR

END IF

ELSE

GOSUB RECEIVE.DATA 'LONGER THEN THREE BYTES IS INCOMING PACKET.

END IF

ELSE

GOSUB RECEIVE.DATA

END IF

ELSE 'Nothing in buffer

END IF

'--------------------- END OF CHECK COMM. BUFFER ------------------------

IF TELEMETRY = 1 AND RETURN.FROM.SEND = 1 THEN

RETURN.FROM.SEND = 0

BUSY = 0

NUMBER.TO.SEND = 0

COLOR 7, 0

GOSUB CLEAR.W2

GOSUB CLEAR.W3

COLOR 0, 7

START.OF.PACKET = 0

PACKET.PTR = 1

GOTO MINI.WORD

ELSE

END IF

KY$ = INKEY$

IF KY$ = "" THEN

GOTO MINI

END IF

IF KY$ = ESC$ THEN

BUSY = 0

NUMBER.TO.SEND = 0

COLOR 7, 0

GOSUB CLEAR.W2

GOSUB CLEAR.W3

COLOR 0, 7

START.OF.PACKET = 0

PACKET.PTR = 1

GOTO MINI.WORD

ELSE

END IF

'---------------------- CHANGE UNIT ADDRESS ----------------------------

IF KY$ = CTRL.N$ THEN

GOSUB CLEAR.W3

LOCATE 23, 1, 1, 5, 7

COLOR 0, 7

INPUT ; "ENTER NEW ADDRESS 1 - 15: ", NODE$

COLOR 7, 0

NODE = VAL(NODE$) AND &HF

Packet$ = CHR$(0) 'PACKET 0

N.BYTES$ = CHR$(2) '2 BYTE MESSAGE

MSG$ = MSG4.TO.VW$ 'SPECIAL MESSAGE FOR VW UNIT - CHANGE NODE ADDR.

TAD$ = CHR$(0)

MSG.FORMAT$ = TAD$ + Packet$ + N.BYTES$ + MSG$ + CHR$(NODE)

PRINT #1, MSG.FORMAT$;

DELAY.TIME! = TIMER

DO WHILE ABS(TIMER - DELAY.TIME!) < 1! 'DELAY FOR BATTERY TEST

LOOP

IF LOC(1) > 0 THEN 'LOOK FOR RESPONSE

GOSUB READ.BUFFER

ELSE

END IF

DATAB$ = ""

KY$ = ALT.A$ 'SET UP NEXT CODE TO READ NEW ADDRESS

ELSE

END IF

'----------------------- GO READ VW ADDRESS -----------------------------

IF KY$ = ALT.A$ THEN

GOSUB CLEAR.W1

COLOR 0, 7

GOSUB GET.ADDRESS

LOCATE 1, 29

PRINT " "; FROM; " ";

KY$ = ""

GOSUB CLEAR.W1

GOSUB CLEAR.W2

GOSUB CLEAR.W3

COLOR 0, 7

LOCATE 23, 1, 1, 5, 7

GOTO MAIN:

ELSE

END IF

'----------------------- TOGGLE BROADCAST FLAG --------------------------

'BROADCAST SENDS MESSAGE TO ALL VW UNITS.

IF KY$ = ALT.B$ THEN

SAVE.X = POS(0)

SAVE.Y = CSRLIN

IF BROADCAST = 1 THEN

BROADCAST = 0

COLOR 7, 0

LOCATE 3, 30, 0

PRINT " ";

COLOR 0, 7

ELSE

BROADCAST = 1

LOCATE 3, 30, 0

PRINT " BROADCAST MODE ENABLED ";

END IF

LOCATE SAVE.Y, SAVE.X, 1, 5, 7

KY$ = ""

ELSE

END IF

'----------------------- TOGGLE TELEMETRY FLAG --------------------------

'TELEMETRY DOES NOT RECEIVE AN "ACK"

IF KY$ = CTRL.T$ THEN

SAVE.X = POS(0)

SAVE.Y = CSRLIN

IF TELEMETRY = 1 THEN

TELEMETRY = 0

Packet = 1

COLOR 7, 0

LOCATE 3, 30, 0

PRINT " ";

COLOR 0, 7

ELSE

TELEMETRY = 1

LOCATE 3, 30, 0

PRINT " TELEMETRY ENABLED ";

END IF

LOCATE SAVE.Y, SAVE.X, 1, 5, 7

KY$ = ""

ELSE

END IF

'------------------------- VW BATTERY TEST COMMAND ------------------

IF KY$ = ALT.V$ THEN 'BATTERY TEST

Packet$ = CHR$(0) 'PACKET 0

N.BYTES$ = CHR$(1) '1 BYTE MESSAGE

MSG$ = MSG2.TO.VW$ 'SPECIAL MESSAGE FOR VW UNIT - BATTERY TEST

TAD$ = CHR$((FROM * 16 + FROM) AND &HFF)

MSG.FORMAT$ = TAD$ + Packet$ + N.BYTES$ + MSG$

PRINT #1, MSG.FORMAT$;

DELAY.TIME! = TIMER

SAVE.X = POS(0)

SAVE.Y = CSRLIN

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30, 0

PRINT " TESTING BATTERY ";

COLOR 0, 7

DO WHILE ABS(TIMER - DELAY.TIME!) < 1! 'DELAY FOR BATTERY TEST

LOOP

IF LOC(1) > 0 THEN 'LOOK FOR RESPONSE

GOSUB READ.BUFFER

IF LEN(DATAB$) = 5 THEN 'ECHO + RETURNED STRING

IF LEFT$(DATAB$, 1) = TAD$ AND MID$(DATAB$, 2, 1) = TAD$ THEN

IF RIGHT$(DATAB$, 1) = MSG2.FROM.VW$ THEN 'BATTERY VOLTAGE OK

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30

PRINT " BATTERY OK ";

COLOR 0, 7

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

ELSEIF RIGHT$(DATAB$, 1) = MSG1.FROM.VW$ THEN

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30

PRINT " LOW BATTERY ";

COLOR 0, 7

BEEP

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

ELSE

COLOR 7, 0 'added 97.05.10

LOCATE 17, 30

PRINT " INVALID TEST - RETRY ALT-V "

COLOR 0, 7

BEEP

GOSUB ShowIt

GOSUB CLEAR.W2

END IF

ELSE

COLOR 7, 0 'added 97.05.10

LOCATE 17, 30

PRINT " INVALID TEST - RETRY ALT-V "

COLOR 0, 7

BEEP

GOSUB ShowIt

GOSUB CLEAR.W2

END IF

ELSE

COLOR 7, 0 'added 97.05.10

LOCATE 17, 30

PRINT " INVALID TEST - RETRY ALT-V "

COLOR 0, 7

BEEP

GOSUB ShowIt

GOSUB CLEAR.W2

END IF

ELSE

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30

PRINT " VW UNIT NOT RESPONDING "; 'tweaked 97.05.10

COLOR 0, 7

BEEP

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

END IF

LOCATE SAVE.Y, SAVE.X, 1, 5, 7

COLOR 0, 7 'added 97.05.10

KY$ = ""

DATAB$ = ""

ELSE

'not ALT-V

END IF

'------------------------- VW SELF TEST COMMAND ------------------

IF KY$ = ALT.T$ THEN 'SELF TEST

Packet$ = CHR$(0) 'PACKET 0

N.BYTES$ = CHR$(1) '1 BYTE MESSAGE

MSG$ = MSG3.TO.VW$ 'SPECIAL MESSAGE FOR VW UNIT - SELF TEST

TAD$ = CHR$((FROM * 16 + FROM) AND &HFF)

MSG.FORMAT$ = TAD$ + Packet$ + N.BYTES$ + MSG$

PRINT #1, MSG.FORMAT$;

DELAY.TIME! = TIMER

SAVE.X = POS(0)

SAVE.Y = CSRLIN

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30, 0

PRINT " TESTING VW UNIT ";

LOCATE 18, 30

PRINT " RESET VW AFTER SELF TEST "; 'tweaked 97.05.10

COLOR 0, 7

DO WHILE ABS(TIMER - DELAY.TIME!) < 2! 'DELAY FOR TEST

LOOP

IF LOC(1) > 0 THEN 'LOOK FOR RESPONSE

GOSUB READ.BUFFER

IF LEN(DATAB$) = 5 THEN 'ECHO + RETURNED STRING

IF LEFT$(DATAB$, 1) = TAD$ AND MID$(DATAB$, 2, 1) = CHR$(0) THEN

IF RIGHT$(DATAB$, 1) = MSG4.FROM.VW$ THEN 'TEST GOOD

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30

PRINT " VW UNIT TEST OK "; 'tweaked 97.05.10

COLOR 0, 7

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

ELSEIF RIGHT$(DATAB$, 1) = MSG3.FROM.VW$ THEN

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30

PRINT " VW FAILED SELF TEST "; 'tweaked 97.05.10

COLOR 0, 7

BEEP

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

ELSE

GOSUB CLEAR.W2 'added 97.05.10

COLOR 7, 0

LOCATE 18, 30

PRINT " INVALID TEST - RETRY ALT-T "

COLOR 0, 7

BEEP

GOSUB ShowIt

GOSUB CLEAR.W2

END IF

ELSE

GOSUB CLEAR.W2 'added 97.05.10

COLOR 7, 0

LOCATE 18, 30

PRINT " INVALID TEST - RETRY ALT-T "

COLOR 0, 7

BEEP

GOSUB ShowIt

GOSUB CLEAR.W2

END IF

ELSE

GOSUB CLEAR.W2

COLOR 7, 0 'added 97.05.10

LOCATE 18, 30

PRINT " INVALID TEST - RETRY ALT-T "

COLOR 0, 7

BEEP

GOSUB ShowIt

GOSUB CLEAR.W2

END IF

ELSE

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30

PRINT " VW UNIT NOT RESPONDING "; 'tweaked 97.05.10

COLOR 0, 7

BEEP

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

END IF

LOCATE SAVE.Y, SAVE.X, 1, 5, 7

COLOR 0, 7 'added 97.05.10

KY$ = ""

DATAB$ = ""

MSG$ = MSG0.TO.VW$ 'SPECIAL MESSAGE FOR VW UNIT - RESET

MSG.FORMAT$ = TAD$ + Packet$ + N.BYTES$ + MSG$

ELSE

'Not self test

END IF

'-------------------- RESET UNIT ---------------------------------

IF KY$ = ALT.R$ THEN 'SELF TEST

Packet$ = CHR$(0) 'PACKET 0

N.BYTES$ = CHR$(1) '1 BYTE MESSAGE

MSG$ = MSG0.TO.VW$ 'SPECIAL MESSAGE FOR VW UNIT - RESET

TAD$ = CHR$((FROM * 16 + FROM) AND &HFF)

MSG.FORMAT$ = TAD$ + Packet$ + N.BYTES$ + MSG$

PRINT #1, MSG.FORMAT$;

SAVE.X = POS(0)

SAVE.Y = CSRLIN

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30, 0

PRINT " VW RESET COMMAND ";

GOSUB ShowIt 'added 97.05.10

GOSUB CLEAR.W2 'added 97.05.10

LOCATE SAVE.Y, SAVE.X, 1, 5, 7

COLOR 0, 7 'added 97.05.10

KY$ = ""

DATAB$ = ""

ELSE

END IF

IF KY$ = ALT.X$ THEN

SAVE.X = POS(0)

SAVE.Y = CSRLIN

GOSUB CLEAR.W2

COLOR 7, 0

LOCATE 17, 30, 0

BEEP

PRINT " EXIT PROGRAM Yes/No ";

COLOR 0, 7

KY$ = ""

DO WHILE KY$ = ""

KY$ = INKEY$

LOOP

IF KY$ = "Y" OR KY$ = "y" THEN

COLOR 7, 0

CLS

END 'end program

ELSE

GOSUB CLEAR.W2 'added 97.05.10

END IF

LOCATE SAVE.Y, SAVE.X, 1, 5, 7

COLOR 0, 7 'added 97.05.10

KY$ = ""

ELSE

END IF

IF KY$ = ALT.C$ THEN

START.OF.PACKET = 0

PACKET.PTR = 1

BUSY = 0

COLOR 7, 0

CLS

GOTO MAIN

ELSE

END IF

IF KY$ = ALT.H$ THEN

COLOR 7, 0

CLS

LOCATE 1, 1, 0

PRINT "<KEY> "

PRINT "<DEL> Deletes line."

PRINT "<BACKSPACE> Deletes character to left."

PRINT "<ENTER> At start of line sends last message."

PRINT "<ALT>+<C> Clears screen."

PRINT "<ESC> Resets "; CHR$(&H22); "SEND PACKET"; CHR$(&H22); " Mode."

PRINT "<ALT>+<S> Invokes set up program."

PRINT "<ALT>+<X> Returns to system."

PRINT "<ALT>+<I> Increments "; CHR$(&H22); "TO"; CHR$(&H22); " address."

PRINT "<ALT>+<D> Decrements "; CHR$(&H22); "TO"; CHR$(&H22); " address."

PRINT "<ALT>+<B> Broadcast i.e. send message to all VW units."

PRINT "<ALT>+<T> Test - VW unit to perform selftest - cycle power after test."

PRINT "<ALT>+<R> Reset - VW unit to start over (warm boot)."

PRINT "<ALT>+<V> VW unit battery voltage test."

PRINT "<ALT>+<A> Read VW address."

PRINT "<F1> To send a full buffer."

PRINT "<CTRL>+<T> For Telemetry."

PRINT "<CTRL>+<N> To change Node address."

LOCATE 23, 30

PRINT "<ANY KEY> to continue ..."

KY$ = ""

DO WHILE KY$ = ""

KY$ = INKEY$

LOOP

CLS

GOTO MAIN

ELSE

'Not ALT-H

END IF

IF KY$ = ALT.I$ OR KY$ = ALT.D$ THEN

IF KY$ = ALT.I$ THEN

TO.ADDR = TO.ADDR + 1

IF TO.ADDR > 15 THEN

TO.ADDR = 1

ELSE

END IF

ELSE

TO.ADDR = TO.ADDR - 1

IF TO.ADDR = 0 THEN

TO.ADDR = 15

ELSE

END IF

TO.ADDR$ = CHR$(TO.ADDR + 48) 'tweaked 97.05.10

SAVE.X = POS(0)

SAVE.Y = CSRLIN

LOCATE 1, 4

COLOR 0, 7

PRINT " ";

PRINT TO.ADDR;

PRINT " ";

LOCATE SAVE.Y, SAVE.X

KY$ = ""

ELSE

END IF

IF KY$ = ALT.S$ THEN

GOSUB SET.CONFIG

GOTO MAIN

ELSE

END IF

IF BUSY > 0 THEN

GOTO MINI 'WAIT FOR COMMUNICATIONS TO COMPLETE

ELSE

END IF

IF KY$ = DEL$ THEN

KY$ = ""

LOCATE 23, 1, 1, 5, 7

PRINT STRING$(80, " ")

LOCATE 23, 1, 1, 5, 7

MESSAGE$ = ""

ELSE

END IF

IF KY$ = BACK$ THEN 'DELETE LAST CHARACTER

KY$ = ""

LT = LEN(MESSAGE$)

IF LT > 0 THEN

MESSAGE$ = LEFT$(MESSAGE$, LT - 1)

PS = POS(0)

IF PS > 1 THEN

PS = PS - 1

LOCATE CSRLIN, PS: PRINT " ";

LOCATE CSRLIN, PS

ELSE

IF CSRLIN > 20 THEN

LN1 = CSRLIN - 1

LOCATE LN1, 80

PRINT " ";

LOCATE LN1, 80

ELSE

END IF

ELSE

END IF

ELSE

END IF

IF KY$ = CR$ THEN

IF MESSAGE$ = "" THEN

MESSAGE$ = LAST.MSG$

ELSE

END IF

IF TELEMETRY = 1 THEN

IF LEN(MESSAGE$) > 30 THEN

MESSAGE$ = LEFT$(MESSAGE$, 30)

ELSE

END IF

GOSUB BUILD.MSG

PACKET.PTR = 1 'POINTS TO ARRAY TO SEND

GOSUB SEND.PACKET

KY$ = ""

ELSE

END IF

IF KY$ = F1$ THEN

MESSAGE$ = FULL.MSG$

LRDM$ = LEFT$(FULL.MSG$, 1)

FULL.MSG$ = RIGHT$(FULL.MSG$, LEN(FULL.MSG$) - 1) + LRDM$

IF TELEMETRY = 1 THEN

MESSAGE$ = LEFT$(FULL.MSG$, 30)

END IF

GOSUB BUILD.MSG

PACKET.PTR = 1 'POINTS TO ARRAY TO SEND

GOSUB SEND.PACKET

KY$ = ""

ELSE

END IF

IF KY$ >= BLANK$ THEN

MESSAGE$ = MESSAGE$ + KY$ 'ADD CHARACTER TO MESSAGE

PRINT KY$; 'PUT IT ON THE SCREEN

IF LEN(MESSAGE$) = 79 OR ((BROADCAST = 1 OR TELEMETRY = 1) AND LEN(MESSAGE$) = 30) THEN

BEEP

GOSUB BUILD.MSG

PACKET.PTR = 1 'POINTS TO ARRAY TO SEND

GOSUB SEND.PACKET

DO UNTIL KY$ = ""

KY$ = INKEY$ 'EMPTY BUFFER

LOOP

ELSE

END IF

KY$ = ""

ELSE

END IF

GOTO MINI

'************* SET UP DISK DRIVE FOR SAVING DATA FILES *******************

SETUP.DSK:

'READ SETUP FILE FROM DISK (edited 97.05.10)

FAULT = 0 'LOOK FOR ERROR CODE

OPEN "VWT97.CFG" FOR INPUT AS #2

IF FAULT = 0 THEN 'FILE IS OPEN

INPUT #2, COM.PORT$, BAUD.RATE$, TO.ADDR$ 'READ CONFIG. VALUES

TO.ADDR = ASC(TO.ADDR$) - 48

CLOSE #2

ELSE

CLOSE #2

GOSUB SET.CONFIG

END IF

RETURN

'------------------- SET CONFIGURATION ---------------------------------

SET.CONFIG:

COLOR 7, 0

CLS

LOCATE 10, 1

PRINT "ADDRESS OF VW UNIT YOU WANT TO TALK TO: "; TO.ADDR$; 'tweaked 97.05.10

LOCATE CSRLIN, 50

PRINT "<1> TO CHANGE."

PRINT "YOUR CURRENT COM PORT - "; COM.PORT$; 'tweaked 97.05.10

LOCATE CSRLIN, 50

PRINT "<2> TO CHANGE."

PRINT "YOUR CURRENT BAUD RATE IS (MATCH TO VW): "; BAUD.RATE$;

LOCATE CSRLIN, 50

PRINT "<3> TO CHANGE."

PRINT "TO EXIT";

LOCATE CSRLIN, 50

PRINT "<ESC>"

LOCATE 20, 1

SETLP0:

KY$ = ""

DO WHILE KY$ = ""

KY$ = INKEY$

LOOP

IF KY$ = "1" THEN

INPUT "ENTER ADDRESS YOU WANT TO TALK TO (1 - 15): ", TO.ADDR$ 'tweaked 97.05.10

TO.ADDR = VAL(TO.ADDR$) AND &HF

GOTO SET.CONFIG

ELSE

END IF

IF KY$ = "2" THEN

IF COM.PORT$ = "COM1:" THEN

COM.PORT$ = "COM2:"

ELSE

COM.PORT$ = "COM1:"

END IF

GOTO SET.CONFIG

ELSE

END IF

IF KY$ = "3" THEN

IF BAUD.RATE$ = "4800" THEN

BAUD.RATE$ = "9600"

ELSEIF BAUD.RATE$ = "9600" THEN

BAUD.RATE$ = "19200"

ELSEIF BAUD.RATE$ = "19200" THEN

BAUD.RATE$ = "4800"

END IF

GOTO SET.CONFIG

ELSE

END IF

IF KY$ = ESC$ THEN

CLOSE #1

OPEN COM.PORT$ + BAUD.RATE$ + ",N,8,1,RS,CD0,DS0,CS0" FOR RANDOM AS #1

CLS

LOCATE 10, 10

PRINT "SAVE CONFIGURATION VALUES TO DISK Y/N ";

LP01:

KY$ = ""

DO WHILE KY$ = ""

KY$ = INKEY$

LOOP

IF KY$ = "Y" OR KY$ = "y" THEN

GOSUB SAVE.CONFIG

RETURN

ELSE

END IF

IF KY$ = "N" OR KY$ = "n" THEN

RETURN

ELSE

END IF

ELSE

END IF

GOTO SETLP0

'-------------------SAVE CONFIGURATION FILE --------------------------

SAVE.CONFIG:

FAULT = 0

OPEN "VWT97.CFG" FOR OUTPUT AS #2

IF FAULT = 0 THEN 'FILE IS OPEN

PRINT #2, CHR$(34); COM.PORT$; CHR$(34); CHR$(34); BAUD.RATE$; CHR$(34); CHR$(34); TO.ADDR$;

CHR$(34)

ELSE

END IF

CLOSE #2

RETURN

'------------- READ COMMUNICATIONS BUFFER HERE AND BUILD STRING -----------

'NOTE: A STRING BUILT AS FOLLOWS - IF THE FIRST CHARACTER IS A NULL

'WILL BE DISPLAYED AS ALL NULLS BY THE QB4.5 DEBUGGER. THE LENGTH IS

'CORRECT AND IS THE ONLY CLUE THAT THE DATA IS REALLY IN THE STRING.

'A LESSEN FROM THE SCHOOL OF HARD KNOCKS.

READ.BUFFER:

'---- CHANGE TO HANDLE NULL CHARACTER

DO WHILE LOC(1) > 0

R.DATAB$ = R.DATAB$ + INPUT$(LOC(1), #1)

COM.TIME! = TIMER

LOOP UNTIL ABS(TIMER - COM.TIME!) > .01 'MAKE SURE ALL RECEIVED

LOOP

IF LEN(R.DATAB$) > 35 THEN

DATAB$ = LEFT$(R.DATAB$, 35)

R.DATAB$ = RIGHT$(R.DATAB$, LEN(R.DATAB$) - 35)

ELSE

DATAB$ = R.DATAB$

R.DATAB$ = ""

END IF

RETURN

'---------------------- LINE EDITOR SCREEN ------------------------------

SCREEN1:

CLS

PRINT "TO: FROM (My address):";

COLOR 0, 7

PRINT " ";

PRINT FROM;

PRINT " ";

LOCATE 1, 4

PRINT " ";

PRINT TO.ADDR;

PRINT " ";

COLOR 7, 0

LOCATE 4, 1

PRINT "MESSAGES RECEIVED";

GOSUB CLEAR.W1

LOCATE 15, 1

PRINT "MESSAGES SENT PACKET# STATUS";

GOSUB CLEAR.W2

LOCATE 21, 1

PRINT "ENTER MESSAGE TO SEND";

GOSUB CLEAR.W3

COLOR 0, 7

LOCATE 25, 1

PRINT " ALT+H FOR HELP ";

LOCATE 25, 18

PRINT " ALT+I or +D "; CHR$(&H22); "TO"; CHR$(&H22); " addr. ";

LOCATE 25, 44

PRINT " ALT+X EXIT PGM. ";

LOCATE 25, 62

PRINT " ALT+B - BROADCAST ";

IF BROADCAST = 0 THEN

COLOR 7, 0

LOCATE 3, 30

PRINT " ";

COLOR 0, 7

ELSE

LOCATE 3, 30

PRINT " BROADCAST MODE ENABLED ";

END IF

IF TELEMETRY = 0 THEN

COLOR 7, 0

LOCATE 3, 30, 0

PRINT " ";

COLOR 0, 7

ELSE

LOCATE 3, 30, 0

PRINT " TELEMETRY ENABLED ";

END IF

LOCATE 23, 1, 1, 5, 7

RETURN

'------------------------ CLEAR RECEIVE WINDOW -------------------------

CLEAR.W1:

COLOR 0, 7

LOCATE 5, 1

FOR A = 1 TO 10

PRINT STRING$(80, " ")

NEXT A

COLOR 7, 0

RETURN

'------------------------ CLEAR SEND WINDOW -------------------------

CLEAR.W2:

COLOR 0, 7

LOCATE 16, 1

FOR A = 1 TO 4

PRINT STRING$(80, " ")

NEXT A

COLOR 7, 0

RETURN

'------------------------ CLEAR EDIT WINDOW -------------------------

CLEAR.W3:

COLOR 0, 7

LOCATE 22, 1

FOR A = 1 TO 2

PRINT STRING$(80, " ")

NEXT A

COLOR 7, 0

RETURN

'------------------ BUILD MESSAGE ARRAY TO SEND TO VW UNIT ----------------

'EACH ARRAY ELEMENT WILL BE <= TO 32 CHARACTERS. THIS IS THE LENGTH OF

'THE MESSAGE BUFFER IN THE VW UNIT.

'THE TOTAL MESSAGE TO BE SENT IS BUFFERED BY ASCII CONTROL CHARACTERS "STX"

'AND "ETX".

'EXAMPLE: A 64 BYTE MESSAGE IS TO BE FORMATED. IT WILL BE DIVIDED INTO 3

'STRINGS AS FOLLOWS:

'1. STX + FIRST 31 CHARACTERS.

'2. NEXT 32 CHARACTERS.

'3. LAST CHARACTER + ETX.

BUILD.MSG:

NUMBER.TO.SEND = 1 'NUMBER OF PACKETS

IF LEN(MESSAGE$) > 30 THEN 'LONGER THEN 1 PACKET

MINI.MSG$(1) = STX$ + LEFT$(MESSAGE$, 31)

MESSAGE$ = RIGHT$(MESSAGE$, (LEN(MESSAGE$) - 31))

L = LEN(MESSAGE$) \ 32

B = (LEN(MESSAGE$) MOD 32)

IF L = 0 THEN

NUMBER.TO.SEND = 2

ELSE

NUMBER.TO.SEND = L + 2

END IF

IF L > 0 THEN

FOR A = 1 TO L

MINI.MSG$(A + 1) = LEFT$(MESSAGE$, 32)

MESSAGE$ = RIGHT$(MESSAGE$, (LEN(MESSAGE$) - 32))

NEXT A

ELSE

END IF

IF B > 0 THEN

MINI.MSG$(L + 2) = RIGHT$(MESSAGE$, B) + ETX$

ELSE

MINI.MSG$(L + 2) = ETX$

END IF

ELSE

MINI.MSG$(1) = STX$ + MESSAGE$ + ETX$

END IF

GOSUB CLEAR.W2

LOCATE 16, 1

COLOR 0, 7

FOR A = 1 TO NUMBER.TO.SEND

PRINT MINI.MSG$(A);

LOCATE CSRLIN, 42

PRT = Packet + A - 1

IF TELEMETRY = 1 THEN

PRINT 8

ELSE

IF PRT < 8 THEN

PRINT PRT

ELSE

PRINT PRT - 7

END IF

NEXT A

GOSUB CLEAR.W3

COLOR 0, 7

LOCATE 23, 1, 1, 5, 7

IF TELEMETRY = 0 THEN

PRINT "BUSY SENDING DATA";

ELSE

END IF

LAST.MSG$ = ""

FOR A = 1 TO NUMBER.TO.SEND

LAST.MSG$ = LAST.MSG$ + MINI.MSG$(A) 'SAVE FOR RETRANSMIT

NEXT A

IF RIGHT$(LAST.MSG$, 1) = ETX$ THEN

LAST.MSG$ = LEFT$(LAST.MSG$, LEN(LAST.MSG$) - 1) 'REMOVE ETX

ELSE

END IF

IF LEFT$(LAST.MSG$, 1) = STX$ THEN

LAST.MSG$ = RIGHT$(LAST.MSG$, LEN(LAST.MSG$) - 1) 'REMOVE STX

ELSE

END IF

MESSAGE$ = ""

RETURN

'----------------------- TRANSMIT PACKET ----------------------------

SEND.PACKET:

IF PACKET.PTR <= NUMBER.TO.SEND THEN

IF TELEMETRY = 1 THEN

RETURN.FROM.SEND = 1

ELSE

RETURN.FROM.SEND = 0

END IF

TO.FROM$ = CHR$((TO.ADDR * 16 + FROM) AND &HFF)

IF BROADCAST = 1 THEN 'SEND TO ALL VW UNITS.

TO.NAME$ = CHR$(0) 'T/F = 00

ELSE

TO.NAME$ = TO.FROM$ 'SEND TO ADDRESSED UNIT

END IF

IF TELEMETRY = 1 THEN

Packet = 8

ELSE

END IF

MSG.FORMAT$ = TO.NAME$ + CHR$(Packet AND &HF) 'ADD PACKET#

MSG.FORMAT$ = MSG.FORMAT$ + CHR$(LEN(MINI.MSG$(PACKET.PTR)) AND &HFF)'#BYTES

MSG.FORMAT$ = MSG.FORMAT$ + MINI.MSG$(PACKET.PTR) 'ADD MESSAGE

TRYS = 0

SEND.AGAIN:

TRYS = TRYS + 1

PRINT #1, LEFT$(MSG.FORMAT$, 1); 'SEND T/F TO GET ATTENTION OF VW UNIT

OK = 2

DELAY.TIME! = TIMER

DO WHILE ABS(TIMER - DELAY.TIME!) < .5 'DELAY FOR RESPONSE

IF LOC(1) > 0 THEN

DATAB$ = INPUT$(LOC(1), #1)

'GOSUB READ.BUFFER ***OLD CODE; NOT FAST ENOUGH FOR DR12xx-DK KITS

'-- A VW UNIT ALWAYS ECHOS FIRST CHARACTER IF NOT BUSY

L = LEN(DATAB$)

IF LEN(DATAB$) = 1 AND DATAB$ = TO.NAME$ THEN 'GOT VW'S ATTENTION

DATAB$ = ""

'--- SEND REMAINDER OF PACKET

PRINT #1, RIGHT$(MSG.FORMAT$, LEN(MSG.FORMAT$) - 1); 'SEND IT

BUSY = 1

OK = 0

EXIT DO

ELSE

OK = 1

END IF

ELSE

END IF

LOOP

IF OK = 1 THEN 'T/F DIDN'T GET THROUGH

IF LEN(DATAB$) = 1 THEN 'VW WAS BUSY AT TIME AND PICKED UP

DATAB$ = ""

DELAY.TIME! = TIMER

'--- DELAY WHILE VW UNIT RECOVERS

DO WHILE ABS(TIMER - DELAY.TIME!) < .5 'DELAY FOR RESPONSE

LOOP

GOTO SEND.AGAIN 'PARTIAL DATA.

ELSE

GOSUB RECEIVE.DATA 'LONGER THEN ONE BYTE IS INCOMING PACKET.

END IF

ELSE

END IF

IF OK = 2 THEN 'NO RESPONSE TIME OUT - TRY AGAIN

IF TRYS < 10 THEN

DELAY.TIME! = TIMER

'--- DELAY WHILE VW UNIT RECOVERS

DO WHILE ABS(TIMER - DELAY.TIME!) < .5 'DELAY FOR RESPONSE

LOOP

GOTO SEND.AGAIN

ELSE

BUSY = 0

NUMBER.TO.SEND = 0

COLOR 7, 1

GOSUB CLEAR.W2

BEEP

LOCATE 17, 5

COLOR 0, 7

PRINT "TIME OUT - VW UNIT NOT RESPONDING."

GOSUB CLEAR.W3

COLOR 0, 7

LOCATE 23, 1, 1, 5, 7

END IF

ELSE

END IF

ELSE

BUSY = 0

END IF

RETURN

'---------------------- RECEIVE PACKETS AND DISPLAY ----------------------

RECEIVE.DATA:

IF LEN(DATAB$) >= 4 THEN 'LENGTH CORRECT FOR RECEIVED PACKET

TT = ((ASC(LEFT$(DATAB$, 1)) AND &HF0) / 16)

'---THIS GETS AROUND NULL CHAR. PROBLEM WITH DEBUGGER

IF TT = FROM OR LEFT$(DATAB$, 1) = CHR$(0) THEN 'MY ADDR.

'--- SEE IF MESSAGE LENGTH = NUMBER OF BYTES

IF ASC(MID$(DATAB$, 3, 1)) = LEN(RIGHT$(DATAB$, LEN(DATAB$) - 3)) THEN

SAVE.Y = CSRLIN

SAVE.X = POS(0)

'---SCROLL RECEIVE WINDOW IF NEEDED

GOSUB SCROLL.WINDOW1

LOCATE RCV.PTRY, RCV.PTRX, 0

' PRINT DATAB$

IF MID$(DATAB$, 4, 1) = STX$ THEN

IF START.OF.PACKET = 1 OR LEN(PRTMSG$) > 0 THEN 'A PACKET WAS LOST

COLOR 7, 0

PRINT " PACKET LOST @ 1 "

COLOR 0, 7

BEEP

START.OF.PACKET = 0 'link overload com reboot 97.05.15

PRTMSG$ = ""

GOSUB BootCom

GOTO MAIN

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

GOSUB SCROLL.WINDOW1

ELSE

END IF

START.OF.PACKET = 1 'USE TO DETECT LOST PACKET

PRTMSG$ = RIGHT$(DATAB$, LEN(DATAB$) - 4) 'REMOVE STX

IF RCV.PTRX > 1 THEN

'PRTMSG$ = CR$ + PRTMSG$ 'STX IN MIDDLE OF LINE IS A NEW START

PRINT CR$;

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

GOSUB SCROLL.WINDOW1

ELSE

END IF

ELSEIF START.OF.PACKET = 1 THEN

PRTMSG$ = PRTMSG$ + RIGHT$(DATAB$, LEN(DATAB$) - 3) 'USE AS IS

ELSE

COLOR 7, 0

PRINT " PACKET LOST @ 2 "

COLOR 0, 7

BEEP

START.OF.PACKET = 0 'link overload com reboot 97.05.15

PRTMSG$ = ""

GOSUB BootCom

GOTO MAIN

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

GOSUB SCROLL.WINDOW1

START.OF.PACKET = 0

PRTMSG$ = ""

END IF

IF RIGHT$(PRTMSG$, 1) = ETX$ THEN 'REMOVE IT AND ADD RETURN.

PRTMSG$ = LEFT$(PRTMSG$, LEN(PRTMSG$) - 1) 'REMOVE ETX

IF LEN(PRTMSG$) > 79 THEN

COLOR 7, 0

PRINT " PACKET LOST @ 3 "

COLOR 0, 7

BEEP

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

GOSUB SCROLL.WINDOW1

START.OF.PACKET = 0

PRINT RIGHT$(PRTMSG$, 79)

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

PRTMSG$ = ""

ELSE

PRINT PRTMSG$ 'PUT MESSAGE ON SCREEN

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

START.OF.PACKET = 0

PRTMSG$ = ""

END IF

ELSE

END IF

RCV.PTRY = CSRLIN 'UPDATE RECEIVE WINDOW POINTERS

RCV.PTRX = POS(0)

LOCATE SAVE.Y, SAVE.X, 1, 5, 7 'RESTORE SCREEN LOCATION

ELSE

END IF

ELSE

END IF

ELSE

END IF

DATAB$ = ""

RETURN

'----------------------- SCROLL RECEIVE WINDOW ----------------------------

SCROLL.WINDOW1:

IF RCV.PTRY >= 15 THEN

RCV.PTRY = 14 'LIMIT TO LAST LINE

RCV.PTRX = 1

FOR A = 5 TO 14

LOCATE A, 1, 0

PRINT STRING$(80, " ");

LOCATE A, 1

FOR B = 1 TO 80

PRINT CHR$(SCREEN(A + 1, B));

NEXT B

NEXT A

LOCATE 14, 1

PRINT STRING$(80, " ");

LOCATE RCV.PTRY, RCV.PTRX

ELSE

END IF

RETURN

'------------------ GET ADDRESS OF VIRTUAL WIRE UNIT ----------

GET.ADDRESS:

Try:

TryIt = 0

Retry:

TryIt = TryIt + 1

LOCATE 10, 20, 0

PRINT "POLLING FOR VIRTUAL WIRE ADDRESS, TRY #"; TryIt;

IF LOC(1) > 0 THEN

DATAB$ = INPUT$(LOC(1), #1) 'CLEAR COMM. BUFFER

ELSE

END IF

DATAB$ = ""

Packet$ = CHR$(0) 'PACKET 0

N.BYTES$ = CHR$(1) '1 BYTE MESSAGE

MSG$ = MSG1.TO.VW$ 'SPECIAL MESSAGE FOR VW UNIT - SEND ADDR.

FROM = 0

TO.FROM$ = CHR$(0) 'GET ADDR. USES T/F =0 AND PACKET = 0

MSG.FORMAT$ = TO.FROM$ + Packet$ + N.BYTES$ + MSG$

PRINT #1, MSG.FORMAT$;

DELAY.TIME! = TIMER

DO WHILE ABS(TIMER - DELAY.TIME!) < .5 'DELAY FOR RESPONSE

LOOP

IF LOC(1) > 0 THEN

GOSUB READ.BUFFER

'-- VW UNIT ALWAYS ECHOS FIRST CHARACTER IF NOT BUSY

P = INSTR(1, DATAB$, MSG5.FROM.VW$)

IF P >= 5 THEN ' VW address message came back

FROM$ = MID$(DATAB$, P - 3, 1)'BACK UP TO T/F

FROM = ASC(FROM$) AND &HF 'got the FROM address from the VW unit

ELSE 'did not get address

END IF

ELSE 'nothing in input buffer

END IF

DATAB$ = ""

IF FROM = 0 THEN 'did not get FROM address, so

IF TryIt < 8 THEN

GOTO Retry 'retry several times automatically

END IF

CLS 'auto retry did not help, let user know

LOCATE 10, 5

PRINT " VW unit not responding - check power, cables, com port, heavy RF noise"

LOCATE 11, 5

PRINT " <R> for retry, <ESC> to main program (then <ALT-S> for configuration set up)"

KY$ = ""

DO WHILE KY$ = ""

KY$ = INKEY$

LOOP

IF KY$ = "r" OR KY$ = "R" THEN

CLS 'added 97.05.10

GOTO Try 'manual retry

ELSE 'drop out to main program for configuration set up

END IF

RETURN

TOADDR.MSG: 'added 97.05.10

COLOR 15, 1

CLS

LOCATE 10, 20, 0

PRINT "Who do you want to talk to today??"

LOCATE 12, 20, 0

PRINT " Double check your TO Address!!"

BEEP

DELAY.TIME! = TIMER

DO WHILE ABS(TIMER - DELAY.TIME!) < 2 'DELAY FOR RESPONSE

LOOP

COLOR 7, 0

CLS

RETURN

ShowIt: 'added 97.05.10

DELAY.TIME! = TIMER

DO WHILE ABS(TIMER - DELAY.TIME!) < 1 'DELAY FOR RESPONSE

LOOP

RETURN

BootCom:

OPEN COM.PORT$ + BAUD.RATE$ + ",N,8,1,RS,CD0,DS0,CS0" FOR RANDOM AS #1 LEN = 2048

RETURN

'******************** ERROR RECOVERY *************************************

PRTERRO:

FAULT = ERR

RESUME NEXT

END

ASH Receiver Block Diagram & Timing Cycle

Antenna

Pulse

Generator

SAW

Delay Line

SAW Filter RFA1 RFA2 Data

Out

Detector &

Low-Pass

Filter

RF Data Pulse

P1 P2

RFA1 Out

RF Input

Delay Line

Out

tPW2

tPW1 tPRI

tPRC

ASH Transceiver Block Diagram

RFA1 RFA2

TXA1TXA2 Log

Antenna

RFIO Detector BB

LPFADJ

PRATE PWIDTH

RXDATA

AGCCAP THLD2THLD1

Power Down

Control

Gain Select

AGC Set

AGC Reset

BBOUT

DS2

DS1

AND

Ref Thld

PKDET

Ref

AGC

8 17 18

14 15 3

13 11 12

VCC1: Pin 2

VCC2: Pin 16

GND1: Pin 1

GND2: Pin 10

GND3: Pin 19

RREF: Pin 11

CMPIN: Pin 6

Low-Pass

Filter Peak

Detector dB Below

Peak Thld

SAW

Delay Line

Modulation

& Bias Control

ESD

Choke

SAW

CR Filter

IN CN

TRL1 CN

TRL0

TXM

TXMOD

Pulse Generator

& RF Amp Bias

AGC

Control Threshold

Control

TH1

TH2

REF

LPF

BBO

PKD

Antenna Mounting Detail

Transceiver

View From Antenna Port of PCB

See component placement

Dwg (Top View) for Antenna

Pad location.

Mount antenna perpendicular

to the Printed Circuit Board

as shown.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Header

Index Dot (PCB Silkscreen)

Node #

Jumper

Locations

Node Programming Jumper Locations

Node # = binary + 1

Schematic, Data Radio

Date: 03/02/1999, LM

Modulation Input

P1-1

GND

Data Out

Vcc

Not Used

Vcc

PTT

Vcc

Data In

Data Output

P1-8

PTT

P1-3

23456789

1213141516171819

+ 3 VDC

P1-2

TR1

R3 R4 R5 R6

R7 R8 R9

R10

R11

R12R13

C4 C5

ANT

PTT

P1-3

R14

R15 R16

+ 3 VDC

P1-2 C2

R17

+ 3 VDC

P1-2

R18

Ref Des Qty RFM P/N Description

PCB1 1 400-1427-001X5 Printed Circuit Board

TR1 1 TR1000/TR1001 Xcvr, TR1000 for DR1200, TR1001 for DR1201

L1 2 500-0583-100 Inductor, SMT, 10 nH, (Coilcraft 0805HT-10NTJ)

L2 1 500-0583-101 Inductor, SMT, 100 nh, (Coilcraft 0805CS-101TK)

L3 1 500-0834-001 Ferrite, Chip Bead (Fair-Rite 2506033017YO)

Q1 1 500-0183-001 Xstr, SOT, MMBT2222L

C1 1 500-0675-106 Capacitor, SMT, 10uf, Kemet T491B106K006AS

C2 1 500-0621-270 Capacitor, SMT, 27 pF, 5%, 0603

C6 1 500-0621-153 Capacitor, SMT, 0.015 uF, %10, 0603

C7 1 500-0621-101 Capacitor, SMT, 100 pF, 5%, 0603

R1 1 500-0620-273 Res, Chip, 27K, .1W, 5%, 0603

R2 1 500-0620-473 Res, Chip, 47K, .1W, 5%, 0603

R3, R5, R16, R17 1 500-0620-001 Res, Chip, 0.0, .1W, 5%, 0603

C3, C4, C5, C8, R4, R6,

R10, R14, R15, 0 000-0000-00 Not Used on DR1200

R7, R8 2 500-0620-274

Res, Chip, 270K, .1W, 5%, 0603

R9, R11 2

Res, Chip, 100K, .1W, 1%, 0603

R12 1 500-0620-303

Res, Chip, 30K, .1W, 5%, 0603

R13 1

500-0620-472 Res, Chip, 4.7K, .1W, 5%, 0603

R18 1

500-0620-101 Res, Chip, 100, .1w, 5%, 0603

P1 1

500-0644-001 HDR, 8Pin

DR1200/DR1201 Bill of Materials

Data Radio Component Placement

916.5 MHz Test Antenna Drawing

Not drawn to scale. Units in inches.

22 AWG insulated solderable magnet wire.

916.5 MHZ ANT

7/07/98 LAM

R.03

.10 .40

1.45

Strip insulation to

bare copper approx.

.125 min, .150 max.

3 turns close wound on .130 in. dia.

400-1309-001

Finished ID = .130, +/- .003

+/- .005

1.950

+/- .025

868.35 Mhz Test Antenna Drawing

Not drawn to scale. Units in inches.

22 AWG insulated solderable magnet wire.

868.35 MHZ ANT

7/07/98 LAM

R.03

.11 .40

1.50

Strip insulation to

bare copper approx.

.125 min, .150 max

3.5 turns close wound on .125 in. dia.

Finished ID = .125, +/- .003

400-1406-001

2.010

+/- .025

+/- .005

CODE IDENT

2U874

DALLAS, TEXAS 75244

DRAWN BY/DATE:

RF Monolithics, Inc.

CHECKED/APPROVED

Lee A. Mrha 5Mar99

TITLE:

SIZE

444-1001-003

SCHEMATIC, Protocol Bd., 19.2Kbs

DWG.

NO. 1/1

REV

XSHEET

REV

NOTES: ECN NO. DESCRIPTION APP/DATE

2U874

1 19 9

4+4.5V

6 5,17,20

+4.5V

+4.5V +4.5V

X1 4

VREF

+4.5V

D3 D4 D5

+4.5V

J1-1

RRX

RTX

+3V

PTT

+3V

L1 D1

U1 U2

MAX218

D2 C7 C8

1 DATA IN (RTX)

2 TX VCC

3 (PTT)

4 RX VCC

5 GND

6 (VREF)

7 RX VCC

8 DATA OUT (RRX)

ADDRESS

ID0

ID1

ID2

ID3

100uf

15uh 1N5819 1uf

1uf

10uf

1uf .1uf

51K

10K

1.8K 10K

MMBT2222

MMBT

2907

22.118

AT89C2051

MHz

1N4148

1uf

+4.5V

154K

100K

+4.5V

+3V

+1.5V

510K

D3, D4, D5 are ultrabright

LED's with cathode to B+.

Polarity may vary with

different LED's.

PB1001-1 Protocol Board

Top Side Component Placement

PB1001-1 Protocol Board

Bottom Side Component Placement

PB1001-1 Protocol Board Bill of Materials

Qty RFM P/N Vendor Vendor P/N Description

1 400-1354-001x1 Printed Circuit Board

1 500-0669-001 Newark 51F2912 Cap, electrolytic, 100uf 25V

5 500-0243-105 Newark 89F5035 Cap, SMT, Kemet T491A105K016AS

1 500-0244-106 Newark 92F5768 Cap, SMT, Kemet T491B106K006AS

1 500-0623-104 Cap, chip, 0805, 0.1uf 25V

1 500-0646-001 Digi-Key 1N5819CT-ND Diode, Schottky, 1N5819

1 500-0051-001 Digi-Key 1N4148CT-ND Diode, High speed switching, JANTX1N4148

3 500-0647-001 Digi-Key LT1034-ND T-1 Ultrabright LED

1 500-0648-001 Digi-Key WM3206-ND PCB connector, Molex 22-02-2085

1 500-0649-001 Newark 89N1583 PCB socket, 9 pin, SPC Technology DE9S-FRS

1 500-0650-001 Newark 44F4268 Inductor, 15uh

1 500-0651-002 Force Electronics 10-89-6084 8 pin dual row header, Molex 10-89-6084

1 500-0183-001 Motorolla MMBT2222AL Xstr, SOT, MMBT2222AL

1 500-0653-001 Newark MMBT2907AL Xstr, SOT, MMBT2907AL

1 500-0022-182 Resistor, chip, 1.8K(J), .2w, 0805

1 500-0732-001 Resistor, chip, 154K, .2w, 1%, 0805

1 500-0673-104 Resistor, chip, 100K, .2w, 1%, 0805

1 500-0022-204 Resistor, chip, 200K(J), .2w, 0805

2 500-0022-513 Resistor, chip, 51K(J), .2w, 0805

1 500-0022-103 Resistor, chip, 10K(J), .2w, 0805

1 500-0724-001 Augat SSTS220PC Switch, DPDT

1 500-0655-002 Digi-Key CTX063-ND

22.1184 MHz Xtal, Series Resonant

2 500-0656-001 Digi-Key ED3320-ND 20 pin IC socket

1 500-0657-001 Digi-Key MAX218CPP-ND

RS232 Transceiver, MAX218CPP

1 500-0658-002 Arrow Electronics

AT89C2051-24PC 24MHz, PDIP, com temp

1 500-0659-002 Keystone 2446

AAA battery holder, single cell

500-0660-001

Digi-Key H560-ND

Screw, 6-32, 1/2 inch, nylon

500-0661-001 Digi-Key H620-ND Nut, 6-32, nylon

500-0665-001 McMaster Carr 9723K22 Bumper feet, .375 square