Device Bluetooth Commands
1. Environment Setup
- Communication test software: sscom32
- Optical probe test fixture
OP Series Bluetooth Module AT Command Protocol
Communication is supported only via serial port (through the optical probe test fixture).
AT Command Format
- AT commands are text-line commands parsed line by line (terminated by carriage return and line feed
\r\n) - AT commands should use uppercase characters (some modules support mixed case). Commands are prefixed with
AT+and fall into parameter-setting commands and read commands - Set command format:
AT+<CMD>=<param>— success returnsOK\r\n, failure returnsERR\r\n - Read command format:
AT+<CMD>— success returns+<CMD>:<param>\r\nOK\r\n, failure returnsERR\r\n - Invalid or unsupported commands return
ERR\r\norERROR\r\n
Command List
Note: All commands end with \r\n. In the serial assistant, enable the “Append CR/LF” option, or enter the full command such as AT+BLENAME\r\n. The AT command set below is continuously being expanded; contact us if you need new features.
| Command | Function | Response | Notes |
|---|---|---|---|
AT |
AT test; returns ok when communication is normal | \r\nok\r\n |
|
AT+RESET |
Save configuration and restart the chip | \r\nok\r\n |
|
AT+RESTORE |
Restore factory settings and restart the chip | \r\nok\r\n |
|
AT+VER |
Query module software version | \r\n +VER=**** \r\nOK |
|
AT+BLENAME |
Query current BLE Bluetooth name | \r\n +NAME=**** \r\nOK |
|
AT+SPPNAME |
Query current SPP Bluetooth name | \r\n +NAME=**** \r\n OK |
Effective only in BLE & SPP dual-mode versions |
AT+BLEMAC |
Query module BLE MAC address | \r\n +MAC:********** \r\n OK |
|
AT+SPPMAC |
Query module SPP MAC address | \r\n +MAC:********** \r\n OK |
Effective only in BLE & SPP dual-mode versions |
AT+BAUD |
Query system baud rate | \r\n +BAUD=**** \r\n OK |
|
AT+UUID |
Query all UUIDs on the chip | ||
AT+MODE |
Query supported modes | \r\n +MODE=* \r\n OK |
Effective only in BLE & SPP dual-mode versions0 = BLE only1 = BLE & SPP |
AT+SECURITY |
Query pairing security mode | \r\n +SECURITY=* \r\n OK |
0 = no PIN pairing1 = simple pairing enabled2 = PIN pairing enabled |
AT+PIN |
Query pairing PIN | \r\n +PIN=****** \r\n OK |
|
AT+ADVDATA |
Query advertising payload data | \r\n +ADVDATA:*** \r\n OK |
|
AT+ADVPARAM |
Query advertising interval | \r\n +ADVPARAM:*** \r\n OK |
|
AT+LPM |
Query low-power mode status | \r\n +LPM=* \r\n OK |
Low-power mode applies only to BLE peripheral mode0 = not in low-power mode1 = in low-power mode |
AT+LOG |
Query chip log output status | \r\n +LOG=* \r\n OK |
0 = disable chip-initiated log output1 = enable chip-initiated log output |
AT+LED |
Query LED status pin behavior | \r\n +LED:X \r\n OK |
0 = off when disconnected (low), steady on when connected (high)1 = fast blink when disconnected, steady on when connected (square wave output; chip default is 1) |
AT+ROLE |
Query current chip role | \r\n +ROLE=**** \r\n OK |
SERVER = peripheral (chip default)CLIENT = central |
AT+VBAT |
Query VBAT voltage | \r\n +PIN=****** \r\n OK |
Query VBAT voltage; e.g. 3.3 V returns 330 |
AT+BAUD=XXXX |
Set serial baud rate; takes effect after reset | \r\nok\r\n |
Parameters include 2400, 4800, 9600, etc.; see section 2.3 |
AT+MODE=X |
Set operating mode | \r\n +MODE=* \r\n OK |
Effective only in BLE & SPP dual-mode versions0 = BLE only1 = BLE & SPP dual mode |
AT+BLENAME=XXXX |
Set BLE channel Bluetooth name; takes effect after reset | \r\nok\r\n |
|
AT+SPPNAME=XXXX |
Set SPP channel Bluetooth name; takes effect after reset | \r\nok\r\n |
|
AT+SECURITY=0 |
Disable pairing; takes effect after reset | \r\nok\r\n |
|
AT+SECURITY=1 |
Enable simple pairing; takes effect after reset | \r\nok\r\n |
|
AT+SECURITY=2 |
Enable PIN pairing; takes effect after reset | \r\nok\r\n |
|
AT+PIN=XXXXXX |
Set pairing PIN to XXXXXX; takes effect after reset | \r\nok\r\n |
BLE channel PIN must be 6 digits (default: 000000) |
AT+BLEMAC=XXXX |
Set BLE MAC address (12-digit hex value); takes effect after reset | \r\nok\r\n |
|
AT+SPPMAC=XXXX |
Set SPP MAC address (12-digit hex value); takes effect after reset | \r\nok\r\n |
Effective only in BLE & SPP dual-mode versions |
AT+ADV=X |
Enable or disable advertising; takes effect after reset | \r\nok\r\n |
0 = off1 = on (default) |
AT+ADVDATA=XXX |
Set advertising payload data | \r\nok\r\n |
|
AT+ADVPARAM=X |
Set advertising interval 10<=X<=4000, unit ms | \r\nok\r\n |
Longer interval = lower power, longer connection time |
AT+RFPWR |
Set transmit power 0–9 | \r\nok\r\n |
Set RF transmit power (default level is 9) |
AT+LED=X |
Set LED indicator behavior | \r\nok\r\n |
0 = off when disconnected (low), steady on when connected (high)1 = fast blink when disconnected (square wave), steady on when connected (high) |
AT+LPM=0 |
Disable low-power mode; takes effect after reset | \r\nok\r\n |
|
AT+LPM=1 |
Enable low-power mode; takes effect after reset | \r\nok\r\n |
Effective only in BLE low-power peripheral mode |
AT+ROLE=X |
Set chip role; takes effect after reset | \r\nok\r\n |
Used for central/peripheral mode switching |
AT+CONN=XXX |
Central role initiates connection | \r\nok\r\n |
XXX = MAC address of the target peripheral |
AT+SLEEP |
Soft shutdown | \r\nok\r\n |
|
AT>X |
Switch to specified channel | \r\nok\r\n |
0 = central channel8 = BLE peripheral channel9 = AT command channel10 = SPP channel |
AT+DISC=X |
Central or peripheral actively disconnects | \r\nok\r\n |
0 = central disconnects8 = BLE peripheral disconnects10 = SPP peripheral disconnectsNote: run AT>9 to switch to the AT command channel before this command |
AT+LOG=X |
Enable or disable chip-initiated log output | \r\nok\r\n |
0 = disable chip-initiated log output1 = enable chip-initiated log output |
AT Commands for Central (Host) Mode Only
| Command | Function | Response | Notes |
|---|---|---|---|
AT+ROLE |
Query current chip role | \r\nok\r\n |
|
AT+ROLE=1 |
Set as central | \r\nok\r\n |
|
AT+ROLE=0 |
Set as peripheral | \r\nok\r\n |
|
AT+ROLE |
Query whether current role is central or peripheral | Central returns “CLIENT”Peripheral returns “SERVER” | |
AT+SCAN=1 |
Start scanning | \r\nok\r\n |
|
AT+SCANM=0,0 |
Set number of devices to find and scan timeout in central mode (unit: seconds) | \r\nok\r\n |
0 <= device count <= 15 (default 5)0 <= timeout <= 40 (default 5)Default returns 5,5 |
AT+SCANPARAM=0,0,0 |
Set scan type, scan interval, and scan window | \r\nok\r\n |
First value: 0 = passive scan, 1 = active scan (default 1)Second value: central scan interval (default 20)Third value: central scan window size (default 15)Note: scan interval must be greater than scan window |
AT+CLRBIND |
Clear saved peripheral addresses | \r\nok\r\n |
|
AT+TARGETUUID |
Set target UUID (service/characteristic) to connect | \r\nok\r\n |
Must include NOTIFY and WRITE/WRITE NO RESPONSE properties, otherwise connection fails |
Baud Rate List
Supported serial baud rates: 2400, 4800, 9600, 14400, 19200, 38400, 56000, 57600, 115200, 230400, 256000, 460800, 530000, 1000000.
3. Bluetooth Transparent Transmission — BLE
3.1 BLE UUID Reference
Insert image
- Service UUID is
18F0. - Characteristic 1 UUID is
2AF0, property isnotify. - Characteristic 2 UUID is
2AF1, property iswrite.
To query the chip’s current UUID configuration, use:
AT+UUID\r\n
UUIDs support 16-bit or 128-bit formats. To use other UUIDs, the chip supports custom UUID configuration as follows:
AT+UUID=[UUID index],[target UUID value]\r\n
AT+RESET\r\n
Examples:
-
Change the UUID labeled “3” in the diagram to
FF47:AT+UUID=3,FF47\r\n AT+RESET\r\n -
Change the UUID labeled “3” in the diagram to
00112233445566778899AABBCCDDEEFF:AT+UUID=3,FFEEDDCCBBAA99887766554433221100\r\n // enter byte-by-byte in reverse order (every two characters) AT+RESET\r\n // after modification, re-pair or restart Bluetooth on the phone for correct display
Other: to restore factory default UUIDs, run AT+RESTORE to reset the chip to factory settings.
3.2 BLE Testing Instructions
For Android app testing, we recommend our Demo app (in the Demo APP directory; currently BLE mode only; SPP mode is under development).
Other professional test tools: nRF Connect (Android version provided in this directory; iOS version available on the App Store).
For iOS app testing, we recommend “BLE Tools”, searchable on the App Store.
Contact us anytime for custom app development.
Test steps:
We use BLE Tools (iOS version, downloaded from the App Store)
- Launch the BLE Tools app;
- Select the device with the matching Bluetooth name, such as “TD5322A”, and tap Connect.
- After connecting, the interface shows the device name and services.
- Locate the required service, which is
FF01; - Tap “Listen”;
- Send test characters from the serial port (e.g. using a PC serial debug tool);
- The phone displays the received characters.
- Locate the required service, which is
FF02; - Tap “Write”;
- Enter test characters;
- Bluetooth transparent transmission forwards the data to the UART on the Bluetooth chip (can be verified with a PC serial