Change the bluetooth module’s baud rate

Example 1: TrèfleSys Mini Bluetooth

Example 2: DIYmultivopter Bluetooth 4.0 (iOS, Andoid, PC, Mac compatible)

Exemple 1: TrèfleSys Mini Bluetooth. This bluetooth module uses AT commands.

By default the configuration is: 115200bps, 8bits, no parity, 1 stop bit, no hardware flow control.

We’ll change from 115200bps to 9600bps.

Step 1: connect the bluetooth module to a FTDI and connect the FTDI to PC/Mac by a usb cable

Step 2: open Arduino and choose the USB port of the FTDI

Step 3: click on the Serial Monitor button

Step 4: choose the actual baud rate of your bluetooth module

Step 5: type “AT” and click on the send button

Step 6: if you see “OK” as response that will mean the bluetooth module is connected at the right baud rate.

Step 7: type “AT+BAUD4” and click on the send button

Step 8: you will see “OK+Set:9600” as response

Step 9: now the baud rate is set as 9600bps, disconnect the bluetooth module to finish.

Baud rate table:

AT+BAUD1 means 1200bps
AT+BAUD2 means 2400bps

1: 1200          8: 115200
2: 2400          9: 230400
3: 4800        10: 460800
4: 9600        11: 921600
5: 19200      12: 1382400
6: 38400
7: 57600

Example 2: for our Bluetooth 4.0 users (iOS, Android, PC, Mac compatible):

bluetooth 4.0

Please read the example 1. The different part is the index number of the baud rate.

Message to send : AT
Receive: OK

Message to send : AT+BAUD?
Receive: OK+Get[Index of the baud rate]

Message to send : AT+BAUD[Index of the baud rate]
Receive: OK+Set[Index of the baud rate]

Index of the baud rate:

AT+BAUD0 means 9600bps
AT+BAUD4 means 115200bps

0: 9600           4: 115200
1: 19200         5: 4800
2: 38400         6: 2400
3: 57600         7: 1200