Cannot sustain connection to peripheral_gatt_dm example

[lpingel]

I am working on my first BLE project  for my employer and have been unable to connect over BLE to our custom board with the nRF52840 processor.  To eliminate issues with my firmware, I then built the nordic peripheral_gatt_dm sample project for my board, changing the prj.conf for single chip operation and enabling the various BT debug messages.  I can see the device with the nRF Connect app on my iPhone SE, but when I attempt to connect to it, the debug messages on the console terminal indicate a quick connect and disconnect sequence, which repeats about every 5 seconds.  I can connect to other BT devices in my office with the app, but the app just shows "connecting" indefinitely for my own device.  This is a sample of  the output I get from the the debug terminal, which is quite similar to what I get on my main application: 
Connected 6C:C6:6A:B7:D0:E5 (random)
No more services
Disconnected from 6C:C6:6A:B7:D0:E5 (random) (reason 0x3e)

I tracked down the reason 0x3e to be BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED, but  I cannot determine the reason for that reason.  

Is this normal for the sample application, or is this just the 13th month of 2020?  

Thank you,

[Jonas Lien]

lpingel said:

Is this normal for the sample application, or is this just the 13th month of 2020?  

LOL, I love this. I feel you.

I'm no Nordic employee, but I'm currently working on a project basing off of the same example. What I do know that a Nordic employee likely would respond is: Need more info. Upload your code and your prj.conf, and perhaps I could spot anything (no promises)

[haakonsh]

Sorry for the late reply. We really do need more information, a sniffer trace would tell us a lot. 

[lpingel]

We actually resolved this with assistance of Nordic FAEs and a private ticket where we sent schematics for our board to Nordic's support staff.  For anyone else having a similar issue, we found that the BLE system requires the use of the 32KHz oscillator to adjust the synchronization for responding to connect.  Since our board did not populate the external oscillator to save cost, we had to enable the internal 32KHz oscillator.  It solved our immediate problem and we could then connect.