connect external custom board programming and debugging result error

[yithwe]

Hi supporter

     SDK version:v2.5.2  IDE: VSCODE computer platform:window10 64 bits

    I try to connect nRF5340-DK or nRF7002-DK to extenal board(nRF7002 and nRF5340 combo modules) from P20, programming and debug was failed as below.I check the VEXT>nRF switch on board is OFF and make sure the external board power is ON.SWDIO connection as below picture as user guide provide, there is no GND DETECT pin on nRF5340-DK board, I use NC pin to instead, why was flash programming failed? what I miss any config for this issue?

[error] [ Client] - Encountered error -102:
Command select_coprocessor executed for 143 milliseconds with result -102
ERROR: Failed when selecting coprocessor APPLICATION
[error] [ Worker] - An unknown error.
ERROR: JLinkARM DLL reported an error. Try again. If error condition
ERROR: persists, run the same command again with argument --log, contact Nordic
ERROR: Semiconductor and provide the generated log.log file to them.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.
FATAL ERROR: command exited with status 33: nrfjprog --program
'c:\ncs\v2.5.2\zephyr\samples\drivers\uart\echo_bot\build_UART12\zephyr\zephyr.hex'
--sectorerase --verify -f NRF53 --coprocessor CP_APPLICATION --snr 1050050568

Best Regards

   Tina

[Simonr]

Hi Tina

How is the external board powered here? It should be powered by its own power source instead of by the DK to ensure correct programming. Do you have a picture of how you've connected the devices exactly? It could also be that the HW of your custom board isn't set up correctly. You can make a private ticket to get a schematics review of your HW done if you'd like.

Best regards,

Simon

[yithwe]

Hi Simonr

                How is the external board powered here?

External board use it's own power by USB or Li-po, my  external board is 3.3 V, first I try to conenct with nRF5340-DK(3.3V) it's can't work, the other hand I try to use level shift change the power level to (1.8V) for our external board  and connect with nRF7002-DK(1.8V), It's also not work.the connect is below, please help for this issue, Thanks.

Best Reagrds

    Tina