Using NRF51X22 as TWI Slave

[Lukas]

I am trying to figure out what is the best way to implement a TWI Slave functionality on the Nordic chips. The HW seems only to support the TWI Master. Is the only way to implement the bus drivers with default GPIO and GPIOTE? Somebody know if there is already some example code somewhere for this? Thanks for your advice.

[Ole Morten]

You're right that the nRF51822 doesn't have a HW TWI slave, so if you need this, you'll have to implement this in software yourself.

However, the new, upcoming chip revision includes an SPI slave, so if changing interface is an option, you could consider trying to use this instead. The future chip revision is described a little bit more here, but for further details, you should contact your sales representative.

[erltot]

Ole Morten: Does the nRF51422 not support i2c slave either?