Connection issues with Android 6.0 Marshmallow and Nexus 6

[Mario Amigot]

Since Google released Android Marshmallow 6.0 we are experiencing problems when connecting our nRF51822 based peripherals to a Nexus 6 phone. The Nexus 6 is able to see our peripherals' advertisements while scanning but when it initiates a connection to a peripheral by sending a CONNECT_REQ packet, in that specific nRF51822 the BLE_GAP_EVT_CONNECTED event is never thrown by the S110 softdevice stack so the connection is never established. The thing is that the same application run in a Nexus 5 with Android 6.0 works without any problem.

Has anybody experienced similar issues with Android 6.0 and Nexus 6? Any idea what may be going on or a solution to this?

[Mario Amigot]

I don't think so...The new 'Location' permission requested by Android 6.0 only affects the fact that a BLE scan can be performed by the app or not. However, we have proved the Nexus 6 with Android 6.0 running either our app or Nordic's nRF Master Control Panel app is still able to find our BLE peripheral device during scan, but it's not able to establish a connection. As I said in my first post, the Nexus 6 seems to send the CONNECT_REQ packet but the BLE peripheral doesn't receive it (or the BLE_GAP_EVT_CONNECTED event is not thrown by the S110 softdevice at least).