nrf52 enabling gpio on nfc pins

RE: nrf52 enabling gpio on nfc pins

cjh39 — Fri, 28 Mar 2025 17:34:52 GMT

The link above does not work anymore..

Im using a nrf52840 , Segger with the nrf SDK.

How do I use the NFC pins as GPIO ? There must be a simple solution to this.

Ive added #define CONFIG_NFCT_PINS_AS_GPIOS 1 to the sdk_config.h and also I added the CONFIG_NFCT_PINS_AS_GPIOS here

When I check the nrfjprog --memrd 0x10001000 --n 512, Im getting all F's

RE: nrf52 enabling gpio on nfc pins

Berker — Wed, 10 Oct 2018 14:20:36 GMT

Thanks for this good response...

RE: nrf52 enabling gpio on nfc pins

felixgattiker@xrite.com — Mon, 18 Jun 2018 08:17:59 GMT

...cool, it works! Thanks for the quick help.

RE: nrf52 enabling gpio on nfc pins

Håkon Alseth — Mon, 18 Jun 2018 07:54:38 GMT

Hi,

This is done by setting the NFCPINS register (note that the UICR is flash, so the NVMC is used to write to this area!). If you add the preprocessor define "CONFIG_NFCT_PINS_AS_GPIOS" (add under project settings -> "Preprocessor" -> "Preprocessor definitions"), you should be able to use these NFC pins as normal GPIOs. This code snippet is shown in the system_nrf52.c file.

If using the nRF52-DK, you'll need to place resistors mounted on R25/R26 to R27/R28, as explained here: http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52/dita/nrf52/development/nrf52_dev_kit/hw_nfc.html?cp=2_1_4_5_10

Best regards,

Håkon