Hello Nordic Engineer's & Expert's! I am working on NRF52840-DK. I want to interface Arduino board with NRF52840-DK using TWI/I2C protocol. Can anyone guide me how to achieve this? Is there any other easy way to interface both?

[IOTsam]

Arduino and NRF52840 Interfacing

[awneil]

Why do you particularly want to use I2C? Wouldn't a UART connection be simpler?

What is the role of the Arduino? The nRF52840 is a Cortex-M4 - far more powerful than most Arduinos!

Anyhow, to do this, you would need to program the NRF52840-DK as an I2C Slave.

The SDK has an example which includes I2C Slave:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.2.0/twi_master_with_twis_slave_example.html?cp=4_0_0_4_5_45

Then you would have to devise some protocol over this link by which your Arduino could communicate with the nRF, and implement that in both the Arduino and the NRF52840-DK  ...