BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED(0x3E) problem

[bin simon]

I'm working with a BLE central device using S120 which is base on ble_app_multilink_central source code. My problem is that I cannot connect to the peripheral ble tag device(specifically the device is LBT-VRU02 of Logitec). After sending the CONNECT_REQ ,S120 sends "Empty PDU" to the peripheral(LBT-VRU02), but no packet comes from the peripheral as follows.

And BLE_GAP_EVT_DISCONNECTED event with reason code 0x3E is notified immediately after BLE_GAP_EVT_CONNECTED event.

First I considered it was the peripheral side problem, but I noticed that the MCP or the LightBlue of iPhone app can connect to the this peripheral with no problem. So, I reconsider that it might be S120 side problem.

The Sniffer log of MCP is below:

I'm using a custom PCB for the my central and peripheral device. And I can connect the S110 peripheral device based on ble_app_multilink_ peripheral source code. I mean that my 120 central device can connect to the Nordic S110 peripheral device without problem.

I'm using the SDK v6.1 and S120 v1.0.0.

I have no idea what causes this problem. Can anyone help me?

[Hung Bui]

Hi Bin,

Could you check and find which chip is inside the LBT-VRU02 ? You can try to use S120 and use the compatibility option we made. This option should be used when connecting to an old 3rd party BLE chip that is not compatible with the default configuration we have on the S120. I suspect it could be the case with the LBT-VRU02.

Please have a look at the release not of the S120 v2.0 in "New functionality" section. You need to use the sd_ble_opt_set() function to stat the compat mode. .