The error is: Error 503, the specified address is not a valid Bluetooth MAC address. I'm not sure what I'm doing wrong. I just downloaded Electronoobs apk app from his youtube video (diagram shown above). I'm using an HC-06 which shows up in other devices under bluetooth settings on my google Pixel.
Thanks for the help! 
I am also getting a similar problem, When i click the listpicker it shows the list of addresses and names, then i click it and the HC-05 shows that it is connected but the app i made says ERROR 503 Not a valid bluetooth mac address
The error is: Error 503, the specified address is not a valid Bluetooth MAC address. I just downloaded apk app. I'm using an HC-06 , shows as paired with my Galaxy S24. Please help if you figured out how to troubleshoot this error. Thanks a lot!
Sharing my code.
