Can't connect to my NRF52840 using a Pico W as a debugger with OpenOCD.

RE: Can't connect to my NRF52840 using a Pico W as a debugger with OpenOCD.

Kasper Larsson-Skauli — Thu, 10 Jul 2025 08:27:05 GMT

Yes, probably the most common mistake, I had wired the wrong pins on the Pico.. Good luck!

RE: Can't connect to my NRF52840 using a Pico W as a debugger with OpenOCD.

ImNoah — Wed, 09 Jul 2025 19:30:48 GMT

Did you ever figure out the solution to this? I have been stuck with this error for hours

RE: Can't connect to my NRF52840 using a Pico W as a debugger with OpenOCD.

Kenneth — Thu, 09 Jan 2025 14:22:23 GMT

[quote user="Kasper Larsson-Skauli"]Could this be because of the access port protection?[/quote]

Very likely yes. We don't really have experience with the platform you are working on.

Kenneth

RE: Can't connect to my NRF52840 using a Pico W as a debugger with OpenOCD.

Kasper Larsson-Skauli — Wed, 08 Jan 2025 14:41:14 GMT

I cannot seem to get the debugger to connect through the swd and swclk pins. It seems OpenOCD throws an error before I can send any command to the chip. Could this be because of the access port protection? Or is it more likely to be a problem with the hardware or debugger?

RE: Can't connect to my NRF52840 using a Pico W as a debugger with OpenOCD.

Kenneth — Wed, 08 Jan 2025 12:54:26 GMT

Hi,

By default the chip will have access port protection enabled, so you need to execute an erase all, this is described here:
https://docs.nordicsemi.com/bundle/nwp_027/page/WP/nwp_027/nWP_027_protected.html

Kenneth