NRF52840 unable to use reset pin (P0.18) as GPIO

RE: NRF52840 unable to use reset pin (P0.18) as GPIO

Kenneth — Fri, 13 Mar 2020 10:16:12 GMT

[quote user="A.P"]Any idea why?[/quote]

Sorry no, maybe you have by accident set a peripheral (uart, twi, spi etc.) to also use pin 18.

Best regards,
Kenneth

RE: NRF52840 unable to use reset pin (P0.18) as GPIO

A.P — Thu, 12 Mar 2020 17:35:30 GMT

This is interesting.
In the Pin_Change_int example P0.18 does work as GPIO. its active state, and pull direction can be changed successfully.
However, none of these work in the BSP example, though I configure everything the same way. Any idea why?

RE: NRF52840 unable to use reset pin (P0.18) as GPIO

Kenneth — Tue, 10 Mar 2020 16:09:59 GMT

I can't see any reason why this shouldn't work no. Maybe try the [nRF5 SDK]\examples\peripheral\pin_change_int for comparison?

RE: NRF52840 unable to use reset pin (P0.18) as GPIO

A.P — Tue, 10 Mar 2020 13:56:33 GMT

Hi Kenneth!
Thank you for the quick reply!

I'm not using the nRF52840-DK, I'm using a custom board.

Here is the uicr.hex file

devzone.nordicsemi.com/.../uicr.hex

RE: NRF52840 unable to use reset pin (P0.18) as GPIO

Kenneth — Tue, 10 Mar 2020 13:46:44 GMT

Hi,

Are you using the nRF52840-DK?

If yes, then flip the DK over an look at the table that show how you should connect P0.18 as an GPIO.
If no, then read back UICR by 'nrfjprog --readuicr uicr.hex' and share it here.

Best regards,
Kenneth