New to this, need help with error 503

MIT App Inventor Help
1

I am in need of help, i’m triying to connect to my ESP-32 board but i always get “Error 503: The specified adress is not a valid Bluetooth MAC adress” and i don’t know how to solve it. Thanks in advance to everyone who answers

some additional info:

  • The MAC adress of the board is C0:CD:D6:CF:C0:7A
  • I have it paired with my phone
  • bluetooth is enabled on the arduiono ide code

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2

Each element of the list AdressesAndNames contains the mac address and name.

You have to extract only the first part, the address ( split the string at a space “ “ )… or simply use the mac address you already know

3

The ESP32 is capable of both Classic BT and BLE: which are you using on it ?

Please be aware that if BLE, then you need to load the dedicated extension.

Moreover, as @davidefa has aleady suggested, since you already know the MAC address of your ESP32, you don’t need to pick it up from a list, just connect it directly.

4

i’m using bluetooth as far as i know. The thing with using a already known adress is that the app needs to be able to function with more than one board so the MAC adress would change

5

For classic Bluetooth this would be the correct blocks assuming you have scan and connect permission

Screenshot_20260504_180938_DuckDuckGo
Screenshot_20260504_180938_DuckDuckGo1080×575 81 KB

If connect ...
Then connected
Else not connected

Taifun

1 Like
6

thanks a lot, the problem has been solved with this

7

NIce to read that @Taifun has helped you to solve !

Best wishes for your project.