nRF52840 configure P0.0 and P0.1 as GPIO

[Nhuan]

Hello,

I would like to use P0.0 and P0.1 as General GPIO for I2C in nRF52840.

I have run the twi_sensor example in SDK 17, it works well with ARDUINO_SCL_PIN and ARDUINO_SDA_PIN, but when I set 

.scl                = NRF_GPIO_PIN_MAP(0, 1),

.sda               = NRF_GPIO_PIN_MAP(0, 0),

the transmission isn't success.

May I ask how can I configure P0.0 and P0.1 as GPIO for TWI (I'm using nRF52840 DK)?

Thank you!

[Jørgen Holmefjord]

Hi,

The P0.00/P0.01 pins are by default connected to the 32.768 kHz crystal on the nRF52840 DK, and disconnected from the pin headers. If you want to use the pins as GPIOs, you can disconnect the crystal as described in the documentation: 32.768 kHz crystal.

Also make sure that you change the LFCLK source from XTAL to RC if you use the LFCLK in your application (always used by SoftDevice if this is enabled for BLE).

Best regards,
Jørgen

[Nhuan]

Could I utilize P0.00/P0.01 pins for TWI without any modifications if my custom board doesn't use the 32.768 kHz crystal?

And do I still need to take this as my application does not yet utilize BLE?

"Also make sure that you change the LFCLK source from XTAL to RC if you use the LFCLK in your application (always used by SoftDevice if this is enabled for BLE)."