TWIM instance crashing on the reconfigured P0.9 and P0.10 pins

[Petar2635]

Hi,

I'm using nrf52840 on a custom board and have a sensor connected over the pins P0.9 and P0.10

which are NFC pins that have been converted to GPIO by using macro (CONFIG_NFCT_PINS_AS_GPIOS).

Both pins work properly as digital output pins, but when using them in the TWIM, the program

crashes after starting the transfer. The TWIM instance is correctly configured because it works on all

the other pins.

What is causing this behaviour?

Thanks in advance

Petar

[Kenneth]

I suspect that there may be capacitance on those pins that prevent the pins to be pulled-up as expected. Are you using internal or external pull-up resistors? If internal, then make sure to have some delay between enabling and before execute transfer. Maybe look at a logic analyzer trace when working and failing.

Best regards,
Kenneth