nRF52832 P0.09/10 GPIOs

[edwardjpalmer]

I have the preprocessor define CONFIG_NFCT_PINS_AS_GPIOS in my code, and GPIO functionality for P0.09 and P0.10 are working just fine for me...

My issue is that even when I configure as output and clear P0.09 as the very first instructions in main(), I am still getting a ~2ms high pulse on P0.09 on processor startup that is causing me problems.

Is there anything I can do at a lower level in software (e.g. in the soft device?) to ensure that P0.09 never goes high on processor startup? I am certain this line is not going high on power-up due to hardware on my board.

[Eric Stutzenberger]

Hi,

Try clearing the pin first and then configuring it as an output.

nrf_gpio_pin_clear(9);
nrf_gpio_cfg_output(9);

HTH,

Eric

[edwardjpalmer]

Eric, I had already tried that, with no change to functionality.

Documentation states that if any overvoltage condition is present on P0.09 or P0.10 when configured as NFC, the pins are shorted internally for protection. Knowing this, I also tried setting P0.10 as output and clearing it, but again, that provided no change to functionality.