I want to send command and receive data to/from a Raspberry Pico W with BLE. I'm using Micropython with aioble lib and I copied programs which work perfectly with the ready to use "nRF Connect". I can check the data received by Micropython are short integer and so I implemented the Appinventor to send this type of data. Nothing happen. Let me highlight that some times ago I could manage BLE communication with an ESP32 programmed with Arduino IDE. I can't guess now what I have to do in AppInventor different
Unfortunately I couldn't find any suggestion on Micropython implementation using BLE. Only traditional Bluetooth where communication is developed with serial communication (easy 
) to external devices like HC-05 or similar. I'd like to use the BLE available on Raspberry Pico W with on board antenna. I guess I couldn't use the traditional way (which is the serial to talk to?)
@mdibit Did you ever resolve this problem? I am having the same issue. I can send and receive to/from my Raspberry Pi Pico W using nRF Connect and I can send data from the Pico to my MIT App, but I am unable to send data from my MIT App to the Pico using BLE.
Right today I re-started fighting again !! I tried to introduce a block in the Screen1.Initialize to get the BLE connect permission. Unfortunately I get "Bluetooth connection has been denied". My problem is I can't find where to give the permission in my Honor10 phone.
What is strange is that if you cancel that request (and then the error) it looks working because you can get the connection to the Pico. The Pico itself shows it's connected but nothing is working.
To be surer I'm now following this guy "https://www.youtube.com/watch?v=RvbWl8rZOoQ"
Controllo_Bluetooth_Car_copia.aia (184.9 KB)
I decided to give up the problem. Anyway I'd like to send you this simple program which works with an Arduino with a HC08 BLE device where I can send "one char string". But there is a new strange behaviour: After you create the apk and load it on the phone, it can't see the Pico BLE. Unbelievable!
Can I ask your Appinventor app where you can at lest read data from Pico ?
Train_Control_008_7.aia (201.8 KB)
Here is what I use to control my Model Railroad Engines. It works fine with Arduino Uno/Nano and HM-10 and with an ESP32. The only problem I am having is with a Pico W.
I just wanted to give you a heads up that I figured out what the problem was. I was advertising a WRITE flag in my Pico. Apparently App Inventor wants to see a WRITE_NO_RESPONSE flag. It seems to have something to do with an Acknowledged vs un-Acknowledged write. Anyway, App Inventor wants to send an un-acknowledged write so as soon as I changed the flag on the pico, everything seems to be working.
Thx, I'll think about it
Michele