Hi I have the sparkfun bluetooth mate silver. I am trying to start working on control via bluetooth for my Arduino. Only thing is I need to set the baud rate for the bluetooth mate, all guides I can find on the net show how to change it via pc. I do not have bluetooth connectivity on my PC. Is there a way to do it via the Arduino?

  • 2
    \$\begingroup\$ I suppose that obtaining a $2 USB Bluetooth radio is not an option? \$\endgroup\$
    – AndrejaKo
    Commented Jun 5, 2011 at 14:04
  • \$\begingroup\$ not today. I will eventually \$\endgroup\$
    – Mark W
    Commented Jun 5, 2011 at 17:09

1 Answer 1


To change the Baud rate on the BlueSmirf, you will need to enter Command mode. To enter Command mode, you need to send "$$$" through the serial port connection. This can be done from a PC using a terminal program or from the Arduino.

Since you want to do this from the Arduino, you will need to write a little bit of code to parse the responses from the BlueSmirf so you can automate the steps necessary to change the Baud rate.

  1. Send "$$$" - Enter Command Mode
  2. Wait for "CMD" - Acknowledge in Command Mode
  3. Send "SU,96" - Change Baud rate to 9600
  4. Wait for "AOK" - Acknowledge command
  5. Send "R,1" - Reboot device to use new setting

All the commands are documented in the RN-42 AT Command Set


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