Bluetooth connectivity for external devices in device farm iOS and Android device

Unfortunately, testing Bluetooth connectivity with external MCU devices is not currently supported in AWS Device Farm for iOS or Android devices.

For iOS devices, the Bluetooth radio state settings are not available in Device Farm at all. This means there is no way to enable or control Bluetooth connectivity for iOS devices in Device Farm testing.

For Android devices, while it is possible to turn on the Bluetooth radio state for a test run, there is no way to actually connect to or interact with external Bluetooth devices like your MCU. The Bluetooth radio can be enabled, but Device Farm does not provide a way to pair or connect with external Bluetooth hardware.

Currently, there is no workaround within Device Farm to test Bluetooth connectivity with external devices. The physical testing you are doing by connecting actual devices is the most reliable method for testing this functionality.

If Bluetooth connectivity is a critical part of your app's functionality, you may need to continue with physical device testing or explore other testing solutions outside of Device Farm that can accommodate external Bluetooth device connections. Device Farm is primarily designed for testing the app itself on different device models, but cannot replicate all real-world connectivity scenarios like external Bluetooth devices.
Sources
Bluetooth settings not available for iOS devices | AWS re:Post