Custom service Characteristic write wrong handle on Samsung

[janR]

Hi

We have problems with Samsung tablets and phones at the moment.

We have an application with two custom services, Secure DFU Service and some standard SIG services, i.e. Battery Service and Device information Service. We are using nRF52832 with SDK14.

The problem is with custom services. We are not able to write values to a custom service characteristics. When I debug, the write event seems to reach the event handler for the custom service, but the event seems to contain the wrong handle (evt.gatts_evt.params.write.handle). The handle seems to be for the CCCD in another characteristics in the same service, instead of the value handle. Data (characteristic value) and everything else seems to be correct.

There is no problem with the SIG services, i.e. we can upload new firmware with Secure DFU.

This is only a problem with some Samsung tablets and -phones we have tested. With Apple ipad, there is no problem.

We are using nRF Connect for testing.

Is this a known problem, and if so, is there a way around?

Regards, Jan

[Hung Bui]

Hi Jan,

Did you do any DFU update that involve a change of the attribute table ? How do you verify that the handle value was not correct ?

When you do service discovery using nRFConnect do you see the correct attribute table ? If you test with a stock example (e.g ble_app_uart) do you see the problem ? ble_app_uart also use customer service.

Note that the phone may automatically enable notification (write to CCCD), could that be the case when you receive the event ?