May 2008 Rev 2 1/38
38
GS-BT2416C1.AT1
Bluetooth® class 1 module with embedded SPP SW
Features
■Bluetooth® specification V.1.2 compliant
■Transmission rate up to 721 Kbps
■Output power class 1 (20 dBm max)
■Working distance up to 100 meters
■ACL and SCO links
■AFH interference resistance
■Supports USB (1.1) /UART/PCM (pulse code
modulation)/SPI/ I²C interfaces
■Optimized link manager and control
■Support wireless LAN coexistence in
collocated scenario
■Integrated 4 Mbit Flash, 64 Kbytes RAM,
4 Kbytes ROM
■3.3 V single supply voltage
■Hardware based UART flow control
Applications
■Serial cable replacement
■Industrial control
■Laptops
■POS terminals
■Data acquisition equipment
■Internet access points
■Machine control
■Sensor monitoring
■Robotic and bionic control
■Security control
■Patient monitoring
■Audio gateway applications
■Hands-free sets
■Wireless printers
■Cordless terminals
■Laptops, PCs and accessories
■Hand held devices and accessories
■HID devices (keyboard, mouse, joystick, game
controller...)
Description
ST Bluetooth® modules are highly integrated for
easy implementation in embedded applications.
Class 1 modules enable wireless communication
with other Bluetooth® enabled devices up to 100
m away. The GS-BT2416C1.AT1 integrates on a
unique FR4 PCB support: BT 1.2 radio and
baseband, memory, 32 kHz and 13 MHz
oscillator, Vreg as well PA function. The module
embeds a complete lower and upper Bluetooth®
stack up to the application support layers
including the generic port profile (GAP) and serial
port profile (SPP), as well the AT command
Interpreter. The antenna has not been included in
order to grant a degree of freedom to the user in
selecting the most suitable design and placement
between external and integrated antenna that
could be SMA aerial or a low cost antenna trace
designed on PCB. For more details pleas refer to
GS-BT2416C1DBAT1 application note.
The GS-BT2416C1.AT1 is the SPP with AT
command module of the GS-BT2416C1.xx series.
GS-BT2416C1.AT1 is BQB pre-qualified.
Conformance testing through Bluetooth®
qualification program enables a fast time to
market after system integration by ensuring a high
degree of compliance and interoperability.
www.st.com
Obsolete Product(s) - Obsolete Product(s)
Obsolete Product(s) - Obsolete Product(s)
Contents GS-BT2416C1.AT1
2/38
Contents
1 Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Operating ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 DC I/O specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Bluetooth® section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1 RF performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Integrate software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 Command interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.3 Usage scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.1 Antenna reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
8.1 Pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
8.2 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9 Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
10 Mechanical dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Contents
3/38
Appendix A AT command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
A.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
A.2 Modes of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
A.3 Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
A.4 Bluetooth® features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
A.5 AT command reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.6 AT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.7 AT + BTCMODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.8 AT+BTDMODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.9 AT+BTPMODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.10 AT+BTSECMODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A.11 AT+BTENCMODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A.12 AT+BTPINCODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
A.13 AT+BTERASELK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
A.14 AT+BTNAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
A.15 AT+BTCLASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
A.16 AT+BTSETTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
A.17 AT+BTINQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
A.18 AT+BTRPORTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
A.19 AT+BTREGPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
A.20 AT+BTMACROSTART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
A.21 AT+BTMACROSTOP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
A.22 AT+BTMACROCLEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
A.23 AT+BTCONNECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
A.24 AT+BTDISCONNECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
A.25 AT+ECHO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
A.26 AT+UARTSETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
A.27 AT+UARTSETUP=? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
A.28 AT+VER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Obsolete Product(s) - Obsolete Product(s)
Contents GS-BT2416C1.AT1
4/38
Appendix B AT event reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
B.1 +BTSETTINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
10.2 +BTRPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
B.2 +BTINQRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
B.3 +UARTSETUP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
B.4 +VER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
B.5 +READY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Appendix C Application examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11 Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
12 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Certifications
5/38
1 Certifications
●CE compliant (IMQ exp. opinion 0081-AREF00017)
– Safety EN60950-1 (2001)
– EMC EN301 489 17V1.2.1
– Radio ES 300 328 V1.6.
– FCC certified on GS-BT2416C1DBAT1 (for a more exhaustive explanation, please
refer to GS-BT2416C1DBAT1 application note)
– FCC ID: S9NBT2416C1DB
●BQB compliant
Obsolete Product(s) - Obsolete Product(s)
Maximum ratings GS-BT2416C1.AT1
6/38
2 Maximum ratings
2.1 Absolute maximum ratings
Absolute maximum ratings (see Ta b l e 1 ) indicate limits beyond which damage to the device
may occur. Sustained exposure to these limits will adversely affect device reliability.
Operating ranges (see Table 2) define the limits for functional operation and parametric
characteristics of the module. Functionality outside these limits is not implied
2.2 Operating ranges
Table 1. Absolute maximum ratings
Symbol Parameter
Values
Unit
Min Max
VDD Module supply voltage 4 V
VIN Input voltage on any digital pin Vss1-0.5 Vdd+0.3 V
Tstg Storage temperature -40 +85 °C
Tsold Soldering temperature 240
Table 2. Operating ranges
Symbol Parameter Conditions
Values
Unit
Min Typ Max
VDD Module supply voltage - 20 °C < T < 70 °C 3.13 3.3 3.47 V
Tstg
Operating ambient
temperature -20 +70 °C
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Electrical characteristics
7/38
3 Electrical characteristics
3.1 DC I/O specification
4 Bluetooth® section
Table 3. DC input / output specification
Symbol Parameter Conditions
Values
Unit
Min Typ Max
Vil Low level input voltage 3.13 V < VDD < 3.47 V 0.8 V
Vih High level input voltage 3.13 V < VDD < 3.47 V 2 V
Vhyst Schmitt trigger hysteresis 3.13 V < VDD < 3.47 V 0.4 V
Vol Low level output voltage Io load = pin drive
capability 0.15 V
Voh High level output voltage Io load = pin drive
capability
VDD-
0.15 V
Table 4. Bluetooth® section
Symbol Parameter Conditions
Values
Unit
Min Typ Max
CHs Channel space 1 MHz
Hop Hopping 1600 Hops/
sec
13M CK System clock 13 MHZ
System clock stability - 20 °C to 70 °C - 20 20 ppm
LP CK Low power clock 32 kHz
Low power clock accuracy - 200 200 ppm
Tra Transmission rate
asynchronous 721 kbits/
sec
Tr s Transmission rate
synchronous 432 kbits/
sec
Iop Operation current TX mode 180 mA
Operation RX mode 60 mA
Obsolete Product(s) - Obsolete Product(s)
Bluetooth® section GS-BT2416C1.AT1
8/38
4.1 RF performance characteristics
In the performance characteristics table the following applies:
●Test condition: nominal
– Voltage typical Vdd = 3.3 V
– Temperature typical TA = 25 °C
Parameters are given at antenna pin
Table 5. Transmitter and receiver performance characteristics
Symbol Parameter Conditions Min Typ Max Unit
TX Pout TX output power
2.402 GHz 18 20 dBm
2.441 GHz 18 20 dBm
2.480 GHz 18 20 dBm
ACP TX output spectrum adjacent
channel power
lM-Nl = 2 - 36 dBm
lM-Nl ≥ 3- 44dBm
RX sens Receiver sensitivity @BER 0.1% - 84 dBm
Table 6. Synthesizer performance characteristics
Symbol Parameter Conditions Min Typ Max Unit
RF in
RF out Input and output frequency range 2402 2480 MHz
TX out TX output spectrum at -20 dB
Bandwidth 920 1000 kHz
∆FTX initial carrier frequency
tolerance - 75 75 kHz
l∆F –pn l TX carrier frequency drift
DH1 data
packet 25 kHz
DH3 data
packet 40 kHz
DH5 data
packet 40 kHz
l∆F/50µsl Drift rate 20 Hz
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Integrate software
9/38
5 Integrate software
The GS-BT2416C1.AT1 implements the following Bluetooth® protocols and profiles:
●L2CAP
●RFCOMM
●SDP
●Generic access profile (GAP)
●Serial port profile (SPP)
Operated through AT command interpreter.
Figure 1. AT1 software implementation
5.1 Features
The module with AT1 implements all Bluetooth® core protocols and serial port profile (SPP)
to replicate UART traffic over a Bluetooth® link.
5.2 Command interface
The module can be fully controlled using AT commands. The AT commands and few
application examples are listed and commented in appendix A.
5.3 Usage scenarios
The module with AT command is dedicated to implement serial cable replacement. An
automatic point to point connection takes place when modules are switched on. Modules
are configured via macro instruction to play the role of master or slave.
B
BA
AS
SE
EB
BA
AN
ND
D
H
HW
W
R
R
F
F
H
HW
W
HCI Bottom La
y
er
Hardware La
y
er
L
LI
IN
NK
K
M
MA
AN
NA
AG
GE
ER
R
H
HC
CI
I
F
FI
IR
R
M
MW
WA
AR
R
E
E
GAP
SPP
RFCOMM SDP
L2CAP
Bluetooth
Protocols and
Profiles
AT command interpreter
Obsolete Product(s) - Obsolete Product(s)
Application information GS-BT2416C1.AT1
10/38
6 Application information
Here below there are some suggestions to better implement the module in the final
application.
●Module is usually put on a motherboard, avoid that traces with switching signals are
routed below the module. The best would be to have a ground plane underneath the
module
●Connect the supply voltage ground of the module with the other grounds present on the
motherboard in a star way.
●Keep the RF ground separate from the module supply voltage ground; the two grounds
are already connected inside the module in one point, see below a possible
implementation.
Figure 2. Module foot print
RF gnd
Module
foot print
Supply voltage GND
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Application information
11/38
6.1 Antenna reference
RF output pin must be connected to an antenna which could be:
●Antenna directly printed on the PCB (Figure 3.)
●Integrated antenna as, for example, antenova® 30-30-A5839-01, Murata
ANCV12G44SAA127, pulse W3008, Yageo CAN4311153002451K. (Figure 4.)
●External antenna connected by means a SMA connector (Figure 5.)
●Despite of the type of antenna chosen, the connection between the RF out pin and the
antenna must be executed in such a way that the connection trace must be matched to
have characteristic impedance (Z0) of 50 Ω to get the maximum power transfer.
●Matching for 50 Ω is depending on the various factors, elements to be taken into
consideration are:
– Type of material, i.e. FR4
– The electrical characteristics of the material,i.e. the εr, electric constant at
2.4 GHz
– Mechanical dimensions of the PCB and traces, i.e. PCB thickness, trace/
reference ground thickness, trace width, trace thickness
– Just to give an example, using a 1 mm thick FR4 board, with an εr = 4.3 at
2.4 GHz, with Cu thickness of 41 µm, the resulted width of 50 Ω strip-line is
1.9 mm (Microstrip type calculation).
Figure 6. Parameters for trace matching
Tools for calculating the characteristic impedance, based on the physical and mechanical
characteristics of the PCB, can be easily found on the web.
Figure 3. Antenna on PCB Figure 4. Antenna examples Figure 5. SMA connector for
external antenna
εr (Dielect ri c cons tant )
PCB
thickness
Tra c e wi d t h
Refe rence ground
Trace thickness
Obsolete Product(s) - Obsolete Product(s)
Block diagram GS-BT2416C1.AT1
12/38
7 Block diagram
Figure 7. Block diagram
32kHz
XTAL
32kHz
XTAL
STLC2416
Baseband
ARM7 proc
STLC2150
Radio chip
RF antenna
FilterSW
LNA
PA
UART
USB
PCM
SPI
I²C
GPIO
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Pin settings
13/38
8 Pin settings
8.1 Pin connections
Figure 8. Pin connection diagram
Obsolete Product(s) - Obsolete Product(s)
Pin settings GS-BT2416C1.AT1
14/38
8.2 Pin descriptions
Table 7. Pin descriptions
Pin N° Name I/O Description
Power, ground and system signal
1Vss
1 --- GND
2 Vdd --- Module supply voltage - single 3.3 V
41 1V8 O 1.8 V digital supply out (test purpose) to be left not connected
42 3V3 O 3.3 V I/O power supply out (test purpose) to be left not connected
43 Vss1 --- GND (test purpose) to be left not connected
44 2V7 O 2.7 digital core supply out (test purpose) to be left not connected
45 RESET I Reset pin (active low)
46 BOOT I External downloading enable (active low) internally pull-upped to 1.8 V by 10 kΩ
13 LP CLOCK OUT O 32 kHz out
26 INT1 (1) External interrupt signal internally connected to VSS1 with 10 kΩ / if not used
connect to VSS1
General purpose signals
3GPIO0
(1) General purpose I/O line
4 GPIO1 I
Bluetooth® link present
5GPIO2
(1) General purpose I/O line
6 GPIO3 I Command/data mode input
7GPIO4
(1) General purpose I/O line
8GPIO5
(1) General purpose I/O line
10 GPIO7 (1) General purpose I/O line
11 GPIO8 (1) General purpose I/O line
12 GPIO9 (1) General purpose I/O line
14 GPIO11 (1) General purpose I/O line
No connect signals
9 ---- (1) Not to be used internally used for RX/TX switch
15 ---- (1) Not to be used internally used for TX gain setting
16 ---- (1) Not to be used internally used for TX gain setting
17 ---- (1) Not to be used internally used for TX gain setting
18 ---- (1) Not to be used internally used for TX gain setting
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Pin settings
15/38
Pin N° Name I/O Description
Test interface signals
19 TDI (1) JTAG pin
20 TDO (1) JTAG pin
21 TMS (1) JTAG pin
22 NTRST (1) JTAG pin
23 TCK (1) JTAG pin If not used connect to VSS1
I2C interface signals
24 I2C_dat (1) I2C bus interface data to be connected to VDD with 10 kΩ resistor
25 I2C_clk (1) I2C bus interface clock to be connected to VDD with 10 kΩ resistor
PCM interface signals
27 PCM_SYNC (1) PCM 8 kHz synch
28 PCM_CLK (1) PCM clock
29 PCM_A (1) PCM data in/out
30 PCM_B (1) PCM data in//out
USB interface signals
31 USB_DN (1) USB data - If not used connect to VSS1
32 USB_DP (1) USB data + If not used connect to VSS1
UART interface signals
33 UART2_RXD I UART2 data input If not used connect to VDD
34 UART2_TXD O UART2 data output
35 UART2_I1 I UART2 clear to send input If not used connect to VDD
36 UART2_02 O UART2 ready to send output
47 UART10_TXD
(1) UART1 data output
48 UART11_RXD (1) UART1 data input If not used connect to VDD
SPI interface signals
37 SPI_FRM (1) Synchronous serial interface frame synch
38 SPI_CLK (1) Synchronous serial interface clock
39 SPI_TXD (1) Synchronous serial interface transmit data
40 SPI_RXD (1) Synchronous serial interface receive data if not used connect to VSS1
Antenna signals
49 Vss2 (RF GND) --- RF GND
50 +ANTENNA --- Antenna out
51 Vss2 (RF GND) --- RF GND
1. Not used with AT command
Table 7. Pin descriptions (continued)
Obsolete Product(s) - Obsolete Product(s)
Soldering GS-BT2416C1.AT1
16/38
9 Soldering
Soldering phase has to be execute with care: in order to avoid undesired melting
phenomenon, particular attention has to be take on the set up of the peak temperature.
Here following some suggestions for the temperature profile based on
IPC/JEDEC J-STD-020C, July 2004 recommendations.
Figure 9. Soldering
Table 8. Soldering
Profile feature PB free assembly
Average ramp up rate (TSMAX to TP) 3 °C / sec max
Preheat
Temperature min (TS min)
Temperature max (TS max)
Time (tS min to tS max) (tS)
150 °C
200 °C
60 – 100 sec
Time maintained above:
Temperature TL
Time tL
217 °C
40 – 70 sec
Peak temperature (Tp) 240 + 0 °C
Time within 5 °C of actual peak temperature (tP) 10 – 20 sec
Ramp down rate 6 °C / sec
Time from 25 °C to peak temperature 8 minutes max
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Mechanical dimensions
17/38
10 Mechanical dimensions
In order to meet environmental requirements, ST offers these devices in ECOPACK®
packages. These packages have a lead-free second level interconnect. The category of
second level interconnect is marked on the package and on the inner box label, in
compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPACK is an ST trademark.
ECOPACK specifications are available at: www.st.com.
Figure 10. Mechanical dimensions
Obsolete Product(s) - Obsolete Product(s)
Mechanical dimensions GS-BT2416C1.AT1
18/38
Figure 11. Land pattern and connection diagram
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT command
19/38
Appendix A AT command
SPP embedded Bluetooth® firmware for STLC2416 based modules version 1.2.1.8
A.1 Introduction
AT command interpreter OBSTFW-101 has been developed by Sycom on its proprietary
Bluetooth® stack
Following data are disclosed with Sycom permission and agreement. All these information
are subject to usual ST reproduction and disclosure rules stated on the last page of the
present document.
10.1 Description
Sycom firmware OBSTFW-101, from now on named .AT1, implements all Bluetooth® core
protocols and serial port profile (SPP) to replicate UART data traffic over a Bluetooth® link.
The module can be fully controlled using AT commands. The throughput over-the-air is up to
~290 Kbps.
A.2 Modes of operation
The module has two modes of operation:
●COMMAND MODE: this mode allows the module to accept AT commands from the
UART. AT commands are used to control any property of the module (Bluetooth® name,
visibility, etc.) as well as to trigger any operation (connection set-up, tear-down,
discovery, etc.)
●DATA MODE: this mode allows the module to send and receive raw data over a
Bluetooth® SPP link. When in DATA MODE each byte transmitted over the UART is
replicated onto the existing Bluetooth® SPP link, and each byte received from the
remote Bluetooth® device is replicated onto the UART port. DATA MODE should be
activated only if a Bluetooth® link has already been setup using AT commands in
COMMAND MODE.
To notice that there is not a default MODE, regardless connection status: this mean that the
active MODE is always established by GPIO3 status.
The external MCU can switch the mode of operation of the module using GPIO3. Both when
the module is turned on or it is switched from DATA MODE to COMMAND MODE a +READY
event is generated. This event informs the external MCU that the module is ready to accept
AT commands. Before the +READY event is generated, no AT commands can be issued to
the module.
Obsolete Product(s) - Obsolete Product(s)
AT command GS-BT2416C1.AT1
20/38
Moreover it is possible to store a startup commands sequence directly into flash memory.
The sequence can be long up to 512bytes. If a macro sequence is present, in startup phase,
some OK events are generated, one for every command of the sequence, before the
+READY event.
This behavior can be avoided setting a AT+ECHO = OFF command starting the macro
(avoiding the +READY too). The sequence execution is stoppable changing the state of
GPIO3 in startup phase.
A.3 Interfaces
The module must be controlled by an external MCU using the UART and 2 GPIOs.
●UART: used to control the module with AT commands (COMMAND MODE), or
send/receive serial data to be transmitted over the SPP Bluetooth® link (DATA MODE).
The first time that the module is powered up, the default UART settings are as following
(saved in flash memory):
Baud rate: (bps) 9600
Data bits: 8
Parity: None
Stop bits: 1
Flow control: None
When these settings are changed by the AT+UARTSETUP command, they are stored in the
flash memory to be reloaded when the module is powered up the next time.
●GPIO1: configured as output. GPIO1 is high when an SPP Bluetooth® link to a remote
device is present. GPIO1 is low when no Bluetooth® link is present.
●GPIO3: configured as input. If GPIO3 is set to high the module switches its mode of
operation to DATA MODE.
If GPIO3 is set to low, the module switches its mode of operation to COMMAND MODE.
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT command
21/38
A.4 Bluetooth® features
.AT1 implements the following Bluetooth® protocols and profiles:
●L2CAP
●RFCOMM
●SDP
●Generic access profile (GAP)
●Serial port profile (SPP)
The embedded SPP can be used in two modes:
●SERVER MODE: This mode allows the module to be connected by other devices. In
this configuration the local module does not initiate a Bluetooth® SPP connection, but
simply exposes an SPP service that can be connected by other devices. In order to
expose an SPP service the AT+BTREGPORT must be used.
●CLIENT MODE: This mode is used to initiate an SPP connection to an SPP service
exposed by a remote Bluetooth® device. To set-up an SPP Bluetooth® link the
AT+BTCONNECT must be used.
The two modes of operation are fully interoperable and the same module can be configured
simultaneously both as a CLIENT and SERVER device. The module only allows a single
Bluetooth® SPP connection to exist at the same time.
When an active connection is present (GPIO1 high) the module is set as “Non-Connectable”
and “Non-Discoverable”, to reduce affection of inquiry scan or connection establishment
attempt.
When no more connection is active the module reset its modes to those previously stored by
“+BTCMODE” and “+BTDMODE” commands.
Obsolete Product(s) - Obsolete Product(s)
AT command GS-BT2416C1.AT1
22/38
A.5 AT command reference
AT commands are used to configure the module and trigger operations. AT commands are
transmitted over the UART channel from the external MCU to the Bluetooth® module. AT
commands have the following syntax:
AT + CMD = parameter0, parameter1, …\0x0D\0x0A
AT + CMD\0x0D\0x0A
Each line must be always terminated by the 0x0D 0x0A characters and only a single
command per line is allowed.
The response to an AT command can be OK if the command was successfully executed, or
ERROR if an error occurred and has the following syntax:
\0x0D\0x0AOK\0x0D\0x0A
\0x0D\0x0AERROR\0x0D\0x0A
Some AT commands can generate events. Events are always reported as follows:
\0x0D\0x0A+EVENT: parameter0, …\0x0D\0x0A
Each event is always bounded by the characters 0x0D 0x0A and can have zero or more
parameters. The command syntax is case insensitive.
A.6 AT
Test the UART communication channel to the Bluetooth® module
Syntax: AT
Return value: OK
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT command
23/38
A.7 AT + BTCMODE
Indicate if the module can be contacted by other Bluetooth® devices. This command does
not register any SPP service.
Syntax: AT+BTCMODE=<0,1>
Parameters:
0: The module cannot be contacted by other Bluetooth® devices (default)
1: The module can be contacted by other Bluetooth® devices
Return value: <OK, ERROR>
A.8 AT+BTDMODE
Indicate if the module can be discovered when an inquiry procedure is performed by other
Bluetooth® devices.
Syntax: AT+BTDMODE=<0,1>
Parameters:
0: The module cannot be discovered by other Bluetooth® devices (default)
1: The module can be discovered by other Bluetooth® devices
Return value: <OK, ERROR
A.9 AT+BTPMODE
Indicate if the module will accept a pairing request incoming from a remote device. The
pairing procedure is necessary in order to authenticate two Bluetooth® devices for the first
time.
Once two devices have been paired, authentication of devices is handled automatically
without the need of any re-pairing, unless link-keys are erased on purpose.
Obsolete Product(s) - Obsolete Product(s)
AT command GS-BT2416C1.AT1
24/38
Syntax: BTPMODE=<0,1>
Parameters
0: The module does not accept pairing requests from a remote Bluetooth® device
(default)
1: The module accepts pairing requests coming from a remote Bluetooth® device
Return value: <OK, ERROR>
A.10 AT+BTSECMODE
Indicate if the module requests the authentication upon the setup of a Bluetooth® SPP link.
An authentication request translates into a pairing request if two devices have never been
paired before.
Syntax: AT+BTSECMODE=<0,1>
Parameters:
0: The module does not request authentication
1: The module requests authentication
Return value: <OK, ERROR>
A.11 AT+BTENCMODE
Indicate if the module requests an encrypted link upon the setup of a Bluetooth® SPP link.
Syntax: AT+BTENCMODE=<0,1>
Parameters:
0: The module does not request encryption
1: The module requests encryption
Return value: <OK, ERROR>
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT command
25/38
A.12 AT+BTPINCODE
Set the pin code of the local module. The module’s pin code is used during a pairing
procedure. In order to be successful, the module’s pin code and the connection pin code
specified during a connection set-up must be identical. See AT+BTCONNECT for more
information.
Syntax: AT+BTPINCODE=”Pincode”
Parameters:
Pincode: 4 to 16-byte string representing the module’s pin code
Return value: <OK, ERROR>
A.13 AT+BTERASELK
Erase all link-keys. When all link-keys are erased the module is unpaired from all previously
paired devices.
Syntax: AT+BTERASELK
Return value: <OK, ERROR>
A.14 AT+BTNAME
Set the local Bluetooth® name. This name is the string shown to all other Bluetooth®
devices.
Syntax: AT+BTNAME=”DeviceName”
Parameters:
DeviceName: A string representing the name of the local device. This string can
be long up to 128 characters.
Return value: <OK, ERROR>
Obsolete Product(s) - Obsolete Product(s)
AT command GS-BT2416C1.AT1
26/38
A.15 AT+BTCLASS
Set the local Bluetooth® Class ID. The Class ID is a 24-bit integer value identifying the type
of device (PC, PDA, Headset, etc.)
Syntax: AT+BTCLASS=DeviceClass
Parameters:
DeviceClass: 24-bit integer value indicating the local device class. This value is
interpreted as an unsigned hexadecimal 24-bit value
Return value: <OK, ERROR>
A.16 AT+BTSETTINGS
Requests the current module settings. The command generates a +BTSETTINGS event.
Syntax: AT+BTSETTINGS=?
Return value: +BTSETTINGS, <OK, ERROR>
A.17 AT+BTINQ
Start an inquiry procedure. The inquiry process allows discovering the list of nearby
Bluetooth® devices. For each device that is found in range a +BTINQRES event is
generated.
Syntax: AT+BTIN Q = InqDuration
Parameters:
InqDuration: Duration in seconds of theinquiry process
Return value: [+BTINQRES], <OK, ERROR>
A.18 AT+BTRPORTS
Query a remote device for SPP services. This command instructs the module to connect to
a remote device and query its SDP (Service Discovery Protocol) Server in order to find SPP
services. For each SPP service found a +BTRPORT event is generated.
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT command
27/38
Syntax: AT+BTRPORTS=BdAddress
Parameters:
BdAddress: Bluetooth® address of the remote device. This value is specified as a
6-byte hexadecimal value: i.e.
AT+BTRPORTS=00230A01F0A5
Return value: [+BTRPORT], <OK, ERROR>
A.19 AT+BTREGPORT
Register a local SPP service that can be opened by other remote Bluetooth® devices.
Syntax: AT+BTREGPORT=”PortName”
Parameters:
PortName: A string representing the name of the local SPP port. This name
appears to remote devices when browsing local services. This string can be long
up to 128 characters.
Return value: <OK, ERROR>
A.20 AT+BTMACROSTART
Set the device in a programmable way. Every AT command coming after, with own
parameters, will not be executed but will be stored in the very insertion order.
This command will be available only if the device is set to COMMAND MODE.
To notice that starting a macro storing sequence will erase any previous present sequence.
Syntax: AT+BTMACROSTART
Return value: <OK, ERROR>
Obsolete Product(s) - Obsolete Product(s)
AT command GS-BT2416C1.AT1
28/38
A.21 AT+BTMACROSTOP
Stop the programmable status and store the commands sequence inserted so far into the
flash memory of the module. If the sequence is larger then memory block available an error
will be raised. The command will be available only if a device is set to COMMAND MODE
and only if it come after an AT+BTMACROSTART command.
Due to internal time needed to write a flash memory area a little
time delay is possible before any return value.
Syntax: AT + B T M AC R OS TO P
Return value: <OK, ERROR>
A.22 AT+BTMACROCLEAR
Erase any possible commands sequence present into the flash memory. This operation is
non-reversible.
Syntax: AT+BTMACROCLEAR
Return value: <OK, ERROR>
A.23 AT+BTCONNECT
Initiate an SPP connection to a remote Bluetooth® device. When the connection has been
successfully established the command returns an OK message and GPIO1 is set to high.
It is possible to specify a number of attempts and a time interval between any retry. It also
possible to stop a sequence of connections retry changing the state of GPIO3 (as with the
startup Macro).
Note: When connected with another device the module become “Non-Connectable” and “Non-
Discoverable”.
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT command
29/38
Syntax: AT+BTCONNECT=BdAddress,PortN, “PinCode”,NRetry, TimeRetry
Parameters:
BdAddress: Bluetooth® address of the remote device. This value is specified as a
6-byte hexadecimal value: i.e.
AT+BTCONNECT=00230A01F0A5
PortN: Port number of the remote SPP port. A value of “0” force the device to
query the remote device for a SPP service port and to get the first valid port; this
behavior is useful for programmed automatic recursive connect.
PinCode: 4 to 16-byte string representing the connection pin code
NRetry: number of possible attempts if the connection fail. A “0” set the device for
infinite attempts. Value range is 0 - 255.
TimeRetry: time interval between attempts in seconds. Value range is 0 - 65535
Return value: <OK, ERROR>
A.24 AT+BTDISCONNECT
Disconnect the current existing SPP Bluetooth® link. When the link has been closed, the
command returns an OK message and GPIO1 is set to low.
Note: See AT+BTCONNECT
Syntax: AT+BTDISCONNECT
Return value: <OK, ERROR>
A.25 AT+ECHO
Enable or disable the output of events and functional messages by the module.
Syntax: AT+ECHO=<ON,OFF>
Parameters:
ON: The ECHO mode is enabled and every message or events by the module will
be outputted. (default)
OFF: The ECHO mode is disabled and no output will be generated.
Return value: <OK, ERROR>
Obsolete Product(s) - Obsolete Product(s)
AT command GS-BT2416C1.AT1
30/38
A.26 AT+UARTSETUP
Set the local UART settings. The changes take affect immediately after the OK response. It
is advisable to issue an AT command after the AT+UARTSETUP in order to make sure the
MCU is synchronized up correctly with the new settings. The new settings are used both for
the COMMAND MODE and DATA MODE. Use the command AT+BTMACROSTART to store
a startup setting for the UART. Is not allowed to use AT+UARTSETUP command in a macro!
Due to internal time needed to write a flash memory area a little time delay is possible
before any return value.
Syntax: AT+UARTSETUP=BaudRate, DataBits, Parity, Stopbits, Fc
Parameters:
Baud Rate: UART baud rate in bps. Possible values are: 300, 1200, 2400, 4800,
9600 (default), 19200, 38400, 57600, 115200, 153600, 230400, 460800.
DataBits: possible values are 5, 6, 7, 8 (default)
Parity: possible values are None (default), Even, Odd
StopBits: possible values are 1 (default), 2
Fc: flow control. Possible values are None (default), Hardware
Return value: <OK, ERROR>
A.27 AT+UARTSETUP=?
Output the current UART configuration settings. The command generates an +UARTSETUP
message with the configuration parameters of the module’s UART. For the parameters list,
see the AT+UARTSETUP command.
Syntax: AT+UARTSETUP=?
Return value: +UARTSETUP, <OK, ERROR>
A.28 AT+VER
Requests the ID, version number and revision date of the firmware. The command
generates a +VER event.
Syntax: AT+VER
Return value: +VER, <OK, ERROR>
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT event reference
31/38
Appendix B AT event reference
B.1 +BTSETTINGS
Outputs the current configuration parameters of the module.
Syntax: +BTSETTINGS: BdAddress, DeviceClass, “DeviceName”, “PinCode”,
ConnectableMode, DiscoverableMode, PairableMode, SecurityMode,
EncryptionMode
Parameters:
BdAddress: Bluetooth® address of the local module. This value is specified as a 6-
byte hexadecimal value: i.e.
+BTSETTINGS=00230A01F0A5, …
DeviceClass: 24-bit integer value indicating the local device class. This value is
interpreted as an unsigned hexadecimal 24-bit value
DeviceName: A string representing the name of the local device. This string can
be long up to 200 characters.
PinCode: 4 to 16-byte string representing the module’s pin code
ConnectableMode: Indicates if the module cannot(=0) / can(=1) be contacted by
other Bluetooth® devices
DiscoverableMode: Indicates if the module cannot(=0) / can(=1) be discovered by
other Bluetooth® devices
PairableMode: Indicates if the module does not accept(=0) / accepts(=1) pairing
requests from a remote Bluetooth® device
SecurityMode: Indicates if the module does not request(=0) / requests(=1)
authentication
EncryptionMode: Indicates if the module does not request(=0) / requests(=1)
encryption
Obsolete Product(s) - Obsolete Product(s)
AT event reference GS-BT2416C1.AT1
32/38
10.2 +BTRPORT
The event is generated only in response to an AT+BTRPORTS command. A +BTRPORT
event is generated for each SPP service found on a remote device. So, for example, if a
remote device exposes two SPP ports, two different +BTRPORT events are generated.
Syntax: +BTRPORT: “ServiceName”, PortN
Parameters:
“ServiceName”: A string representing the name of the SPP service as it has been
registered on the remote Bluetooth® device.
PortN: An integer value representing the port number of the remote SPP service.
B.2 +BTINQRES
The event is generated only in response to an AT+BTINQ command. A +BTINQRES event
is generated for each device found during an inquiry process.
Syntax: +BTINQRES: BdAddress, “BdName”
Parameters:
BdAddress: Bluetooth® address of the remote device. This value is specified as a
6-byte hexadecimal value: i.e.
AT+BTINQ=00230A01F0A5
“BdName”: A string representing the name of the remote Bluetooth® device
B.3 +UARTSETUP
Outputs the UART current configuration parameters.
Syntax: +UARTSETUP: BaudRate, DataBits, Parity, StopBits, Fc
Parameters: BaudRate: UART baud rate in bps.
Possible values are: 300, 1200, 2400, 4800, 9600 (default), 19200, 38400, 57600,
115200, 153600, 230400, 460800.
DataBits: possible values are 5, 6, 7, 8 (default)
Parity: possible values are None (default), Even, Odd
StopBits: possible values are 1 (default), 2
Fc: flow control. Possible values are None (default), Hardware
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 AT event reference
33/38
B.4 +VER
Indicates the ID, version number and revision date of the firmware.
Syntax: +VER: ID, Ver, RevDate
Parameters:
ID: Firmware ID indicating the model
Ver : Version of the firmware
RevDate: Firmware revision date in DDMMYY format.
B.5 +READY
Indicates the module is ready to accept AT commands.
The +READY message is generated when the module is started and when the mode is
switched from DATA MODE to
COMMAND MODE.
Syntax: +READY
Obsolete Product(s) - Obsolete Product(s)
Application examples GS-BT2416C1.AT1
34/38
Appendix C Application examples
The following section provides two application examples demonstrating how two .AT1
equipped modules can be configured in order to act as a CLIENT and as a SERVER and
connect to each other using the SPP service. The CLIENT has the Bluetooth® address
00800010AA01, while the SERVER has the Bluetooth® address 00800010AA02.
Configuring the SERVER: this AT command list sets the module discoverable and
connectable by other devices. It enables security and creates an SPP service called “SPP
Port”.
AT
OK
AT + B T CM O D E = 1
OK
AT+BTPMODE=1
OK
AT + B T DM O D E = 1
OK
AT+BTSECMODE=1
OK
AT+BTENCMODE=0
OK
AT+BTPINCODE=”1234”
OK
AT+BTNAME=”SPP Server”
OK
AT+BTCLASS=52020C
OK
AT+BTREGPORT=”SPP Port”
OK
Configuring the CLIENT: this AT command list configures the module as a CLIENT.
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1 Application examples
35/38
AT
OK
AT + B T CM O D E = 0
OK
AT+BTPMODE=1
OK
AT + B T DM O D E = 0
OK
AT+BTSECMODE=1
OK
AT+BTENCMODE=0
OK
AT+BTNAME=”SPP Client”
OK
AT+BTCLASS=52020C
OK
The following AT commands are issued on the CLIENT module to set-up a connection to the
server module: in this example only one connection attempt is required, the TimeRetry
parameter is ignored. First, an inquiry is performed to discover nearby Bluetooth® devices.
Once all devices have been found a connection is made to the found device (SERVER).
AT+ B T I N Q = 1 0
+BTINQRES: 00800010AA02, ”SPP Server”
OK
AT+BTRPORTS=00800010AA02
+BTRPORT: “SPP Port”, 1
OK
AT+BTCONNECT=00800010AA02, 1, “1234”, 1, 0
OK
Obsolete Product(s) - Obsolete Product(s)
Ordering information scheme GS-BT2416C1.AT1
36/38
11 Ordering information scheme
Table 9. Ordering information scheme
GS-BT 2416 C1 AT1
Bluetooth® modules
V 1.2 compliant
Class 1
SPD plus AT command
Obsolete Product(s) - Obsolete Product(s)
GS-BT2416C1.AT1
38/38
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any
time, without notice.
All ST products are sold pursuant to ST’s terms and conditions of sale.
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such
third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.
UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT
RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING
APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY,
DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE
GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any
liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
© 2008 STMicroelectronics - All rights reserved
STMicroelectronics group of companies
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -
Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America
www.st.com
