About the "BLE_GAP_EVT_DISCONNECTED" event nRF52832

Question

Hello. 
 After pairing with a tablet or computer, if you leave it for a few seconds without operating it 
 
 I wrote out the cause of the disconnection by debugging. 
 "Error 34 (0x22): GATT CONN LMP TIMEOUT" 
 
 What are the possible causes and countermeasures?

Einar Thorsrud · Accepted Answer

Hi, 
 Thank for these files. They were much more informative. Here I see from the sniffer trace (Disconnect.pcapng) that the nRF disconnects with reason BLE_HCI_CONN_INTERVAL_UNACCEPTABLE (0x3B) in #1977, #2783 and #3592. 
 You write that you do not see this if you include line 50, which delays the next connection parameter a very long time (24 hours, which I assume is longer than the time you test). Therefore my first assumption was that the conn_params module disconnected, but that is not the case as you have set disconnect_on_fail = false . 
 The actual reason this fails is that you explicitly disconnect on the BLE_CONN_PARAMS_EVT_FAILED event in your ConnectParamsEventHandler() function, with the reason BLE_HCI_CONN_INTERVAL_UNACCEPTABLE . So the nRF is doing exactly as you would expect with this code. If you do not want to disconnect even when you do not get the connection parameters you request, you should remove line 670 - 678 in your BLEControl.c. 
 Einar