We have a device which connects to two other devices as a central, and also is connected to by a third device (Mobile Phone) as a peripheral.
When updating the Bluetooth firmware binary from version 1.20.0 to 1.21.0 we have started experiencing disconnections from the third device, downgrading back to 1.20.0 resolves any issues.
A summary of the connection flow is detailed below:
- Device A (Peripheral) and Device B (Peripheral) are scanned for and connected to by Device C (Central)
- Device C (Peripheral) Advertises and is scanned for and connected to by Device D (Central)
- Device C soon stops responding to Device D and a connection timeout occurs (this is seen on wireshark and is not always the same point in the connection)
This behaviour is not observed, and the connection seems to be stable when Device C only connects to one of Device A or B before connecting to Device D, it also seems stable if the following sequence is performed:
- Device A or B (Peripheral) connected to Device C (Central)
- Device C (Peripheral) connected to Device D (Central)
- Device B or A (Peripheral) connected to Device C (Central)
- Device C can then be disconnected from Device D and reconnected manually without any timeout issues.
This suggests to me that it relates to the order in which devices are connected, however there could be other factors.
Has anyone else experienced anything similar, or got any suggestions on test I could perform to narrow down the cause.
Many Thanks, Graham
