nRF52840-DK - Can´t program

[Joao Dullius]

I have a nRF52840-DK that stopped programing.

As a starting point to get it back to work, I reflashed the Interface MCU Firmware.

It is correctly detected by J-Link Configurator as follows:

It is also detected by VSCode Plugin:

But, any attempt of erase, recover ou flash fails.

When I try to use the nRF for Desktop Programmer, I get the following error:

SW6 is set to default. SW9 is set to VDD.

I would appreciate some help to get it back to work conditions.

[Kenneth]

Hello,

A few debug steps you can try,

1. Download and install latest nrf command line tools, run "nrfjprog --recover":
https://www.nordicsemi.com/Products/Development-tools/nrf-command-line-tools/download

2. Try to connect P0.18 directly to VDD in case you have by accident enabled pin reset, then run "nrfjprog --recover".

3. Check that you have not by accident cut solder bridges to measure current consumption, in that case you need to place some jumpers on P22 and P23.

Best regards,
Kenneth

[Joao Dullius]

Hi Kenneth,

By connecting P0.18 to VDD, I was able to run the recover and program the board, but I always need to send a reset command after programing. It is not auto-reseting after programing and the BOOT/RESET button in the board is not running.

If I disconnect P0.18 from VDD, I can no longer program the board.

[Kenneth]

It sounds to me that you by accident or intentionally enable pin reset, and that you somewhere in your project try to set P0.18 to low output. A combination of these two will make the chip unusable unless P0.18 is forced high (e.g. to VDD).

You can for instance disable pin reset by setting CONFIG_GPIO_AS_PINRESET=n in prj.conf

Kenneth

[Joao Dullius]

Thanks, will try that!