Cannot entry in function write callback after a write with nRFConnect

[Vincent25]

Project context:
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Server BLE  for home trainer diy

Target  (Bluetooth server) : Bluefruit nRF52 The feather
Library : BluefruitBLE
Client : nRF Connect (Android)

Problem:

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I cannot entry the function callback  on a write of a characteristic.

I use nRF Connect for this job, and i push the send button but it doesn't work.

with the framework of bluefruit, it works fine with the cccd_callback!!!

My questions:

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Is there any samples of using callbacks "OnWrite" (implementation for the server) ?

How can we debug a handshake for a control point beetween server and client (gatt protocol)?

Thank you.

Vincent

[Vincent25]

Hi,

Now I successfully entry the function callback.

The reason was the permission which was unappropriate.

But now I want to ask for informations about the handshake (flow chart) to implement for the server when a client write a control point.

I didn't find any sample about this, and there is no detailled sequence diagram (uml) in the GATT specifications.

I want to implement the Fitness Machine Control Point, but i think a lot of control point are built on the same template.

Thank you

best regards

Vincent

[Kenneth]

I tried to answer this in :https://devzone.nordicsemi.com/f/nordic-q-a/56188/general-question-about-the-gatt-concept-of-control-point