Using STM32WB for bidirectional smartphone application

[YGail.2]

I developed a prototype using a UART to Bluetooth dongle, the HC-05. This worked like a charm. I could pair my smartphone to it and continuously send data between the MCU Board and my smartphone.

Now I want to optimize size and cost, therefore I choose the WB15 to do the same task. However, I'm struggling really hard, as I'm not sure which protocol GATT, GAP, L2CC, etc. I have to choose.

For example, I could manage to advertise, however when I want to pair my smartphone tells me I need a particular app to pair the WB15. Hence, the WB is only recognized as BLE Sensor and not as a bidirectional server/client.

In short, I need something like the transparent mode, but the data transfer must be between the two cores and not over the UART.

I'm struggling so much with the WB that I'm thinking to change to an ESP32 or rolling back to a System on a Chip like the BlueNRG which manages all the data transfer.

[Javier1]

>>However, I'm struggling really hard,

Do not worry, What you want to do with BLE is not as straight foward as bluetooth classic.

So your struggle is shared by a lot of people.

>>I'm not sure which protocol GATT, GAP, L2CC, etc. I have to choose.

You need to learn about the BLE stack, good luck in your journey, you as well start here or here

Start getting familiar with the terms profiles , services and characteristics.

I advise you to download this app in your phone

>> I need something like the transparent mode

Every manufacturer does it different, no standard protocol yet. (here is ST example)

>>I'm struggling so much with the WB that I'm thinking to change to an ESP32 or rolling back to a System on a Chip like the BlueNRG which manages all the data transfer.

Thats also an option.

[YGail.2]

Thx for the answer. Actually after many readings today about the ESP32 I learned the difference between classic bluetooth and BLE. This article resumes pretty well my problem:

​https://circuitdigest.com/microcontroller-projects/using-classic-bluetooth-in-esp32-and-toogle-an-led

Hence, Stms WB can only handle BLE and not classic bluetooth I have to switch on an ESP32. Pretty sad...​