Notify is not reading any value on Android using NRF BLE

[ssh]

I'm developing an Android app which should read sensor values of a BLE sensor on a high frequency (at least 25hz). The nRF Toolbox is receiving the values on the Notify property, but if I implement it by my own I don't receive the notify/or values accordingly.

As template I have used the BlinkyApp and developed the callbacks accordingly. How can I debug this or are there any common problems?

I can read data from the bluetooth device using

readCharacteristic(imuCharacteristic).with(dataCallback).enqueue()

but it won't read if the device send an notify.

Thanks in advanced

[bjorn-spockeli]

Have you enabled notifications by writing to the characteristics CCCD?

[ssh]

Thank you for your response!

No, I don't write to the CCCD. Do i need to to this explicitly? I have't found such a call in the blinky example yet.

[ssh]

I had to add the CCCD in the server code. After adding this, the client receives the notification

[ssh]

Sadly the proposed solution does not work reliably.
The app does connect and enable notify on the gatt, but not always receives notifications. If a device works, I can disconnect and reconnect without any problems, but often I won't even receive the first notification.

However, nrf connect is working well. Though I haven't checked the transimssion interval (20hz) yet,