Can not connect to devices with SDK 13 from android 4.4.4

[Sourabh Barve]

Hi, I use the NRF-toolbox app's UART feature for connecting to nordic devices. Android version is 4.4.4 and the device used is a Samsung device. Everything was working fine when nordic device was using SDK 11, Softdevice S132 v3. But after migration to SDK 13 and softdevice S132 v4.0.2, connection does not go through. The connect request succeeds, but service discovery fails with GAT_INTERNAL_ERROR (0x81). This is followed by a disconnection of the device (GATT_ERROR 0x85). Same behaviour is seen through NRF-connect app as well.

Is support for 4.4.4 android dropped from SDK 13, softdevice S132v4.0.2? Or are there any known issues?

Thanks

[FormerMember]

In SDK 13, a "GATT module" was introduced and is enabled by default. This module enables MTU request and Data Packet Length extension (DLE). For all phones supporting BLE 4.2 and above, the examples in the SDK will work out of the box.

For phones that support BLE 4.0 and/or BLE 4.1 only, MTU request and DLE will not work. In that case, you will have to disable it in the SDK example: all you need to do is to comment out gatt_init().

[Sourabh Barve]

Thanks Kristin. It worked. If only nrf_ble_gatt_init() is commented instead of entire gatt_init(), it also works on devices supporting BLE4.2.