Connectivity android(bt 4.0) with nrf52832(sd s132v5).

Question

Hello. 
 I have some questions. Is it possible stabile work of android device , that has bluetooth 4.0 , with nordic device on base softdevice s132 v 5.0 ? What should i read, if i want to do it? 
 My first experience is connection to nordic device by android with bluetooth 4.0. How result, connection established and we could read default characteristics, as device name etc, but when i tried to write into custom characteristics, response of nordic device to android is "error 3, gatt write not permitted". 
 In other case, when other android was in connection with nordic device, write into custom characteristics is fine. 
 Best regards!

endnode · Accepted Answer

Sure, BLE is designed backward compatible so fact that you are using Nordic stack which has BT5 features doesn't mean it cannot work with legacy devices. 
 When it comes to your GATT error(s) there will probably be other problems on that layer, either permissions have changed on Server side or one Client was authorized and second not. Indeed there might be even other rare issue under the hood (e.g. messing up GATT handles so Client might target wrong handle) but from your poor description nothing can be concluded. Get full trace from radio, read it, analyze steps on SM and GATT layer and you will probably find the root cause quickly.

Connectivity android(bt 4.0) with nrf52832(sd s132v5).

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