nRF Master Control Panel Android App fails to connect

[sachingarg2k1]

Hi,

I am using two Android devices with nRF Master Control Panel (BLE v4.0.5) app installed on both. I am using one Android device (Moto G 3rd Gen Android v6.0) as the peripheral with GATT server. The other device (Samsung Galaxy S3 GT-i9300 v4.3) in Central role listens for BLE advertisements and is able to discover the peripheral device. It then tries to connect but the connection attempt never succeeds. GATT server on peripheral device has connectable property set to True.

The logs on the Central device say: Connecting to gatt = device.connectGATT(autoConnect=false)

So, it seems connect request is sent out from central device but never reaches the peripheral device as there is nothing in the logs on peripheral device. I tried hosting peripheral on various devices and only one device (Moto G First Gen Android 5.x) so far has shown expected result. What could be the reason for this?

[Aleksander Nowakowski]

Hi,

You will be able to connect to an advertising Android device, with the Connectable flag set only with a device that supports resolvable addresses. Android supports them since Android 5.0 Lollipop. You won't be able to connect to it using an older version of this system. Your test device (Samsung S3) has Android 4.3 so it will fail.

Best Regards, Aleksander

[sachingarg2k1]

Thanks Aleksander for your reply!! But I am not sure about one aspect here. You said that Central device must support resolvable addresses (i.e. has to have Android 5.0 atleast). But where as my Central device (Galaxy S3 Android 4.3) is unable to connect to Advertising module running on Galaxy S4, it is able to connect to Advertising module running on MotoG first generation!! So, in short the same Central mode device demonstrate different behavior with two different peripheral mode device. Please clarify!!

[Aleksander Nowakowski]

I'd say that the MotoG does not use the resolvable addresses when advertises. That's why you can connect to is with Galaxy S3. There is also a chance, that you won't be able to connect from MotoG to your advertising S4. Or they support it in peripheral mode...