I2C bus with no external pull up

[Joseph]

Hi,

We are using nRF51422 in our project and we observe a strange thing, that even there is no external pull up resistors, the I2C communication using the built-in TWI port is still working fine, I would like to check with you whether this is the case that the mcu will activate the internal pull up while in I2C mode.

Thank you! Joseph

[Petter Myhre]

Hi Joseph

The nRF51422 supports internal pullups for use with the TWI module. Unmodified, our hardware TWI driver uses internal pullups. I would examine how the GPIOs are configured to find out.

Please let me know if there is anything else.

[Antonio]

Are these internal pullup present even when the nRF51422 is sleeping?

Thanks,