nrf51822 Central disconnection problem

[Aymen Rejeb]

Hi all,

Using nRF51422 on nRF51-DK as a Central I have been successfully connected to a non-Nordic BLE peripheral, however when using the ISP130301 chip that embedding an nRF51822_CEAA (256 Ko/ 16 Ko) the Central is being disconnected with the 0x8 (BLE_HCI_CONNECTION_TIMEOUT) or 0x3E (BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED) disconnection reasons.

Could anyone please give a hint here! what could be the reason of the disconnection?

This is the Wireshark trace file: trace.pcapng

nRF51822 Revision:

Debugging the disconnection:

ble_app_uart_c trace: trace_27_07_16.pcapng

ISP schematic:

ISP picture

[Petter Myhre]

I see from the datasheet that the frequency tolerance of the low frequency crystal is +-40 ppm, but in the code you have used NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, see ble_stack_init(). Maybe you can try with NRF_CLOCK_LFCLKSRC_XTAL_50_PPM or NRF_CLOCK_LFCLKSRC_RC_250_PPM_TEMP_4000MS_CALIBRATION and see if that makes any difference?