aci_gap_create_connection() returns 0x3a

[HLin.3]

I have a STM32WB that serves as the master and four other as the slaves.

As the slaves may sometimes go offline, the master will periodically tries to connect with them (say, every 10 seconds). Between two connection attempts, the master allows the connected slaves to transmit data. At the 10-second mark, the master asks the connected slaves to pause transmission while it tries to connect with disconnected ones.

However, it seems that the master cannot connect to other devices once some slaves begin data transmission as the call to `aci_gap_create_connection()` returns error code 0x3a. I also discovered that `aci_gap_create_connection()` would be successful only when all slaves were disconnected.

Does it have anything to do with the BLE link layer state? My guess is that the master cannot connect to other slaves if it is in the connected state, but I don't know how to verify it. And if it is true, how can I ask the master to switch to the standby state so as to connect with other slaves? Please help, thanks!

[Remy ISSALYS · Accepted solution]

Hello,

The ACI_GAP_CREATE_CONNECTION return 0x3a (e.g Controller Busy) when a procedure is already running and not finish, surely a connection update procedure (e.g ACI_GAP_START_CONNECTION_UPDATE command).

Best Regards

[HLin.3]

Thank you. I've found that to be the problem.