Failed connection to BLE pulseoximeter (Jumper JPD-500F) - immediate BLE_GAP_EVT_DISCONNECTED

[elwas]

Hello,

we're trying to develop central BLE application on nRF52840 using SDK 16.0.0 and S140 softdevice to connect with BLE pulseoximeter (Jumper JPD-500F - it uses TLSR8266 IC for BLE), but shortly after connection event (BLE_GAP_EVT_CONNECTED) we're receiving disconnection event (BLE_GAP_EVT_DISCONNECTED) with error code 0x3E (BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED).

Sniffing result for failed connection:

We've tried both tests with success:

• connection to other peripheral devices (nRF52840 S140) from our firmware
• connection from mobile using nRF connect
  Sniffing results:
  

Do you have any suggestions how we can fix it?

[Edvin]

Hello,

Can you please capture a sniffer trace using the nRF Sniffer?

The disconnect reason with BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHEDi is occuring at the peripheral? And the peripheral is an nRF? What is the central? A Phone or another nRF?

BR,

Edvin