How do I connect an RN4x module with an Android™ device?

To connect a Bluetooth® classic device as an RN42 module with an Android™ device, you have to configure the RN4x module as a slave, and have the Android device scan for it.

Follow the steps to configure the RN4x module as a slave:


Put the device in command mode by sending the $ command. The device returns CMD to indicate it is in command mode.


Send SM,0 to put the device into slave mode.


Verify that the device is in slave mode by issuing the D action command. Look for the MODE = Slav message.


Reboot the device using the R,1 command.

The changes do not take effect until the device is rebooted. On the Android device, go to Bluetooth settings and then pair with the RN4x module. Open an application which can exchange data between the module and the phone.

Android is a trademark of Google LLC.

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