AVR 8-bit Microcontrollers
ATtiny104 Xplained Nano
USER GUIDE
Preface
The Atmel® ATtiny104 Xplained Nano evaluation kit is a hardware platform to
evaluate the ATtiny104 microcontroller.
Supported by the Atmel Studio integrated development platform, the kit
provides easy access to the features of the Atmel ATtiny104 and explains
how to integrate the device in a custom design.
The Xplained Nano MCU series evaluation kits include an on-board mini
embedded programmer, and no external tools are necessary to program the
ATtiny104.
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Table of Contents
Preface............................................................................................................................ 1
1. Introduction................................................................................................................3
1.1. Features....................................................................................................................................... 3
1.2. Kit Overview................................................................................................................................. 3
2. Getting Started...........................................................................................................4
2.1. Xplained Nano Quick Start........................................................................................................... 4
2.2. Design Documentation and Relevant Links................................................................................. 4
3. Xplained Nano........................................................................................................... 5
3.1. Mini Embedded Debugger............................................................................................................5
3.2. Power Sources............................................................................................................................. 5
3.3. Xplained Nano Standard Pin-out..................................................................................................6
3.4. Disconnecting mEDBG.................................................................................................................7
4. Hardware User Guide................................................................................................9
4.1. Connectors................................................................................................................................... 9
4.2. Current Measurement...................................................................................................................9
4.3. Peripherals................................................................................................................................. 10
5. Embedded Debugger Implementation..................................................................... 11
5.1. Tiny Program Interface............................................................................................................... 11
5.2. Virtual COM Port.........................................................................................................................11
6. Hardware Revision History and Known Issues........................................................12
6.1. Identifying Product ID and Revision........................................................................................... 12
6.2. Revision 2...................................................................................................................................12
6.3. Revision 1...................................................................................................................................12
7. Document Revision History..................................................................................... 13
8. Evaluation Board/Kit Important Notice.....................................................................14
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1. Introduction
1.1. Features
ATtiny104 microcontroller
One yellow user LED
One mechanical button
mEDBG
Auto-ID for board identification in Atmel Studio
One green board status LED
Programming
Virtual COM port (CDC)
USB powered
1.2. Kit Overview
The Atmel ATtiny104 Xplained Nano evaluation kit is a hardware platform to evaluate the Atmel
ATtiny104.
Figure 1-1. ATtiny104 Xplained Nano Evaluation Kit Overview
RESET
TPI DATA
TPI CLK
NC
VREG
VUSB
GND
CLK OUT
CDC T X
CDC RX
VCC
PA0
PA1
PA2
PA3
PA4
PA5
GND
PB3
PB2
PB1
PB0
PA7
PA6
Micro USB Con nector
User LED User button
mEDBG
ATtiny104
Power discon nect mEDBG d is connectStatus LED
TPI CLK
TPI DATA
RESET
USER LED
USER BTN
CDC T X
CDC RX
Power
Ground
Clock
Serial
Target I/O
Shared I/Os
Program/Debug
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2. Getting Started
2.1. Xplained Nano Quick Start
Steps to start exploring the Atmel Xplained Nano platform:
1. Download Atmel Studio.
2. Launch Atmel Studio.
3. Connect a USB cable (Standard-A to Micro-B or Micro-AB) between the PC and the USB port on
the kit.
When the Xplained Nano kit is connected to your computer for the first time, the operating system will
perform a driver software installation. The driver file supports both 32- and 64-bit versions of Microsoft®
Windows® XP, Windows Vista®, Windows 7, Windows 8, and Windows 10. The drivers for the kit are
included with Atmel Studio.
Once the Xplained Nano board is powered the green status LED will blink and Atmel Studio will auto
detect which Xplained Nano board is connected. Atmel Studio will present relevant information like
datasheets and kit documentation. The ATtiny104 device is programmed by the on-board Mini Embedded
Debugger and therefore no external programmer tool is required.
2.2. Design Documentation and Relevant Links
The following list contains links to the most relevant documents and software for the ATtiny104 Xplained
Nano.
Xplained products - Atmel Xplained evaluation kits are a series of easy-to-use evaluation kits for
Atmel microcontrollers and other Atmel products. For low pin-count devices the Xplained Nano
series provides a minimalistic solution with access to all I/O pins of the target microcontroller.
Xplained Mini kits are for medium pin-count devices and adds Arduino Uno compatible header
footprint and a prototyping area. Xplained Pro kits are for medium to high pin-count devices, they
features advanced debugging and standardized extensions for peripheral functions. All these kits
have on board programmers/debuggers which creates a set of low-cost boards for evaluation and
demonstration of features and capabilities of different Atmel products.
Atmel Studio - Free Atmel IDE for development of C/C++ and assembler code for Atmel
microcontrollers.
Atmel sample store - Atmel sample store where you can order samples of devices.
Atmel Data Visualizer - Atmel Data Visualizer is a program used for processing and visualizing
data. Data Visualizer can receive data from various sources such as the Embedded Debugger Data
Gateway Interface found on Xplained Pro boards and COM ports.
Design Documentation - Package containing CAD source, schematics, BOM, assembly drawings,
3D plots, layer plots etc.
Hardware Users Guide in PDF format - PDF version of this User Guide.
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3. Xplained Nano
Xplained Nano is an evaluation platform that provides a set of small boards with access to all
microcontoller I/O's. The platform consists of a series of low pin-count Microcontroller (MCU) boards,
which are integrated with Atmel Studio to present relevant user guides, application notes, datasheets, and
example code through Atmel Studio. The platform also features a Virtual COM port for serial
communication to a host PC.
3.1. Mini Embedded Debugger
The ATtiny104 Xplained Nano contains the Atmel Mini Embedded Debugger (mEDBG) for on-board
programming. The mEDBG is a composite USB device of two interfaces; a debugger and a Virtual COM
Port.
Together with Atmel Studio, the mEDBG debugger interface can program the ATtiny104. On ATtiny104
Xplained Nano, the TPI interface is connected between the mEDBG and the ATtiny104.
The Virtual COM Port is connected to a UART on the ATtiny104 and provides an easy way to
communicate with the target application through terminal software. It offers variable baud rate, parity, and
stop bit settings.
Note:  The settings on the ATtiny104 must match the settings given in the terminal software.
Info:  The virtual COM port in the mEDBG requires the terminal software to set the data
terminal ready (DTR) signal to enable the UART pins connected to the ATtiny104. If the DTR
signal is not enabled the UART pins on the mEDBG is kept in high-z (tristate) rendering the
COM port unusable. The DTR signal is set automatically by some terminal software, but it may
have to be manually enabled in your terminal.
The mEDBG controls one status LED on ATtiny104 Xplained Nano. The table below shows how the LED
is controlled in different operation modes.
Table 3-1. mEDBG LED Control
Operation mode Status LED
Power up LED is lit briefly
Normal operation LED is not lit
Programming Activity indicator; LED flashes when programming/
debugging with the mEDBG
3.1.1. Xplained Nano Clock Output
The mEDBG output its CPU clock to the CLK pin 8 as shown in Xplained Nano Standard Pin-out. The
clock output can be used to feed the target device with a more accurate clock if this is needed for the
application.
3.2. Power Sources
The ATtiny104 Xplained Nano kit can be powered by different sources. By default the kit will have a 5V
supply and the voltage is taken directly from the USB port through a 500mA PTC fuse. The voltage from
the USB connector can vary between 4.4V to 5.25V (according to USB spec).
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If other voltages are required, the kit must be disconnected from the USB to avoid damage or contention
to the USB power. The mEDBG must also be disconnected from the target section of the board. The
board can be power by applying a voltage to one of the power connections on the board according to the
table below. To avoid any power leakage through the mEDBG, this should also be disconnected by
removing the resistors shown in Figure 3-3. For placement of power connections, see Xplained Nano
Standard Pin-out.
Table 3-2. Power Connections
Power
Connection
Description
VUSB USB Voltage output when USB is connected (behind a PTC fuse). Can be used as
power input when USB is not used.
VREG Regulated voltage from VUSB. If the kit does not have a regulator, this is directly
connected to VUSB.
VCC Target voltage supply. By default connected to VREG through a 0Ω resistor. Apply
external voltage here if the resistor is removed.
Figure 3-1. Power Supply Block Diagram
USB Target MCUPTC
Power source
Power connection
Power consumer
0-ohm Resistor
VUSB /
VREG VCC
mEDBG
3.3. Xplained Nano Standard Pin-out
Xplained Nano kits have a standard pin-out in the mEDBG section as shown in the tables and figure
below. The program/debug pins will change depending on the target interface, but will remain at the same
locations.
Xplained Nano kits have a target section where all I/O pins will be available and fanned out. Except for
the VCC and GND pins with fixed positions, there are no defined pin functions in this area. The first pin in
the target area is the VCC pin, located right next to the VREG pin of the standard section. The last pin is
GND, and it's located next to the CDC RX pin in the standard section. For reference, see figure below.
3.3.1. Standard Pin-out for TPI
Table 3-3. Xplained Nano mEDBG Standard Pin-Out
Pin number Name Description
1 RST Reset line
2 TPID TPI Program data line
3 TPIC TPI Program clock output
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Pin number Name Description
4 NC No Connect
5 VREG Regulated voltage or VUSB if no regulator present
6 UART RX mEDBG UART RX line
7 UART TX mEDBG UART TX line
8 CLK mEDBG clock output
9 GND Ground
10 VUSB USB voltage
Figure 3-2. Xplained Nano Standard Pin-out for TPI
RESET
TPI DATA
TPI CLK
NC
VREG
VUSB
GND
CLK OUT
CDC TX
CDC RX
VCC GND
Micro USB ConnectormEDBGPower disconnect Status LED
3.4. Disconnecting mEDBG
The target controller ATtiny104 can be completely separated from the mEDBG, but this requires some
small modifications to the board using a soldering iron. By removing the resistors in the sections shown in
the figure below, the mEDBG is completely disconnected from the target controller. If desired to connect
the mEDBG again, solder in 0Ω resistors or solder in 100-mil headers on the header footprints and use
wire-straps to connect the interfaces.
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Figure 3-3. Kit Modifications
Power disconnect mEDBG disconnect
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4. Hardware User Guide
4.1. Connectors
4.1.1. ATtiny104 Xplained Nano Pin-out
The ATtiny104 Xplained Nano has a direct fan-out of the I/O pins of the device and all I/O's are accessible
at the edge connectors.
Table 4-1. Edge Connector
Edge
connector
ATtiny104
pin
Functions Shared functionality
1 VCC Power supply
2 PA[0] PCINT0/ADC0/AIN0/T0/CLKI/TPICLK mEDBG TPI Clock
3 PA[1] PCINT1/ADC1/AIN1/OC0B/TPIDATA mEDBG TPI Data
4 PA[2] PCINT2/RESET mEDBG Reset
5 PA[3] PCINT3/OC0A
6 PA[4] PCINT4/ICP0
7 PA[5] PCINT5/ADC2/OC0B User LED
8 PA[6] PCINT6/ADC3
9 PA[7] PCINT7
10 PB[0] PCINT8/ADC4
11 PB[1] PCINT9/INT0/ADC5/XCK0/OC0A/CLKO User button
12 PB[2] PCINT10/ADC6/TxD0/ICP0 mEDBG CDC RX
13 PB[3] PCINT11/ADC7/ACO/RxD0/T0 mEDBG CDC TX
14 GND Ground
4.2. Current Measurement
The power to the target controller ATtiny104 is connected from the VREG supply to the targets VCC
supply with a 0Ω resistor as shown in the figure below. To measure the power consumption of the device,
remove the 0Ω resistor and replace it with an ammeter. The ammeter can be connected between the
VREG and VCC pads for easy measurement.
Tip:  To connect the two power domains again, solder in a 0Ω resistor on the footprint or a 100-
mil header on the header footprint at the edge of the board and place a jumper between VREG
and VCC.
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Caution:  Removing the resistor while the kit is powered without an ammeter or jumper may
cause the ATtiny104 to be powered through its I/O pins. This may cause permanent damage to
the device.
Figure 4-1. Current Measurement
VREG
VCC
Power disconnect
4.3. Peripherals
4.3.1. LED
There is one yellow LED available on the ATtiny104 Xplained Nano board that can be turned ON and
OFF. The LED can be activated by driving the connected I/O line to GND.
Table 4-2. LED Connection
ATtiny104 pin Function Shared functionality
PA5 Yellow LED0 Edge connector
4.3.2. Mechanical Buttons
ATtiny104 Xplained Nano contains one mechanical button. This is a generic user configurable button and
when a button is pressed it will drive the I/O line to GND.
Info:  There is no pull-up resistor connected to the generic user button. Remember to enable
the internal pull-up in the ATtiny104 to use the button.
Table 4-3. Mechanical Button
ATtiny104 pin Description Shared functionality
PB1 User button Edge connector
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5. Embedded Debugger Implementation
ATtiny104 Xplained Nano contains a Mini Embedded Debugger (mEDBG) that can be used to program
the ATtiny104 using Tiny Program Interface (TPI). The mEDBG also include a Virtual Com port interface
over UART. Atmel Studio can be used as a front end for the Mini Embedded Debugger.
5.1. Tiny Program Interface
The Tiny Program Interface (TPI) uses two pins to communicate with the target. For further information on
how to use the programming capabilities of the mEDBG, see Mini Embedded Debugger.
Table 5-1. TPI Connections
ATtiny104 pin Function Shared functionality
PA0 TPI clock mEDBG
PA1 TPI data mEDBG
5.2. Virtual COM Port
The Embedded Debugger acts as a Virtual Com Port gateway by using one of the ATtiny104 UARTs. For
further information on how to use the Virtual COM port, see Mini Embedded Debugger.
Table 5-2. Virtual COM Port Connections
ATtiny104 pin Function Shared functionality
PB2 UART TXD (ATtiny104 TX line) mEDBG CDC RX
PB3 UART RXD (ATtiny104 RX line) mEDBG CDC TX
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6. Hardware Revision History and Known Issues
This user guide is written to reflect the latest available revision of the kit. This chapter contains
information about known issues, a revision history of older revisions, and how older revisions differ from
the latest revision.
6.1. Identifying Product ID and Revision
The revision and product identifier of Xplained Nano boards can be found in two ways; either through
Atmel Studio or by looking at the sticker on the bottom side of the PCB.
By connecting an Xplained Nano board to a computer with Atmel Studio running, an information window
will pop up. The first six digits of the serial number, which is listed under kit details, contain the product
identifier and revision.
The same information can be found on the sticker on the bottom side of the PCB. Most kits will print the
identifier and revision in plain text as A09-nnnn\rr, where nnnn is the identifier and rr is the revision.
Boards with limited space have a sticker with only a QR-code, which contains a serial number string.
The serial number string has the following format:
"nnnnrrssssssssss"
n = product identifier
r = revision
s = serial number
The product identifier for ATtiny104 Xplained Nano is A09-2678.
6.2. Revision 2
The target device U200 on revision 2 of the kit has been changed from engineering samples
(ATTINY104-SSNRES) to non-engineering samples (ATTINY104-SSNR).
6.3. Revision 1
Revision 1 is the initially released revision.
Engineering samples are mounted on revision 1 for the target device U200 (ATTINY104-SSNRES).
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7. Document Revision History
Doc. rev. Date Comment
42671B 08/2016 Add revision 2 information.
42671A 02/2016 Initial document release.
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8. Evaluation Board/Kit Important Notice
This evaluation board/kit is intended for use for FURTHER ENGINEERING, DEVELOPMENT,
DEMONSTRATION, OR EVALUATION PURPOSES ONLY. It is not a finished product and may not
(yet) comply with some or any technical or legal requirements that are applicable to finished products,
including, without limitation, directives regarding electromagnetic compatibility, recycling (WEEE), FCC,
CE or UL (except as may be otherwise noted on the board/kit). Atmel supplied this board/kit "AS IS",
without any warranties, with all faults, at the buyer's and further users' sole risk. The user assumes all
responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies Atmel
from all claims arising from the handling or use of the goods. Due to the open construction of the
product, it is the user's responsibility to take any and all appropriate precautions with regard to
electrostatic discharge and any other technical or legal concerns.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER USER NOR ATMEL
SHALL BE LIABLE TO EACH OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES.
No license is granted under any patent right or other intellectual property right of Atmel covering or
relating to any machine, process, or combination in which such Atmel products or services might be or
are used.
Mailing Address: Atmel Corporation
1600 Technology Drive
San Jose, CA 95110
USA
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Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com
© 2016 Atmel Corporation. / Rev.: Atmel-42671B-ATtiny104-Xplained-Nano_User Guide-08/2016
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