my nrf52833 board cannot start (reset ) normally

[nick yong]

my nrf52833 board cannot work after power. but can start when I run nrfjprog --reset .
but when I power down and power on the nrf52833 board, it do not work.

the following is my board. (No nfc)

please check and tell me .  what caused the reset issue (power off and power on cannot start<boot> the board )
thanks。

[Szabolcs]

Hi,

The nRF has an internal pullup on the reset line, and does not need a resistor on it. Can you remove R36 and try again?

[nick yong]

I try and remove this pullup resistor. the observation is just the same.
And I find another issue:
the SWD interface did not works well.
for example:

the reset and eraseall command would run into trouble too. (sometimes it works well. sometimes it fail)
nrfjprog --reset
[error] [ Client] - Encountered error -102: Command read_device_info executed for 40 milliseconds with result -102
[error] [ Worker] - An unknown error.
[error] [ Client] - Encountered error -102: Command read_memory_descriptors executed for 44 milliseconds with result -102
Failed to read device memories.
[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.

my swd and swsck is connected to DK pin
vs code <------> 52833DK <------>my board.
would you please tell me how can I handle this 19,20pin (swdio,swdsck)?
would you please give me reference design for SWD interface?

[Szabolcs]

Did nrfjprog --reset broke after you removed the resistor, or was it the same before?

Here is a post about using the devkit with an external board: https://devzone.nordicsemi.com/f/nordic-q-a/102480/how-to-program-an-external-board-using-a-dk-board

Please also try to connect to the target with J-Link commander.

[nick yong]

I do have 10K pull up resistor。
the same thing .

I can debug only once. If i need debug again. I must repower and recover reset it again.
my package is QDAA(40pin). different from DIAA(DK)

QFN40 is different from other package?
my code and proj.cnf works well for DK (pin73).

[Szabolcs]

Hi,

the package is only a difference in pin count, the chip inside is the same.

So you can always connect after a recover, and then cannot connect after programming the chip. This tells me that you have a configuration in your project which disabled the debug interface. What project are you flashing on the board? Does this issue occur if you try with another firmware?