Hi! I would like to test the RPi3 + Arduino UNO + DHT22 over I2C communication: RPi3 send a request to Arduino. Arduino use the DHT22 sensor (temp, humidity) and send back the results to RPi. I tested the RPi3+GPIO+DHT22 communication. It works fine! :) But I would like to use the I2C, because it is elegant, fine solution.
The Arduino has power with USB cable. Do I need to use resistors like this: I2C configuration Or just I connect the RPi3 I2C GPIO pins to the Arduino UNO SDA/SCL pins directly?
(So the the RPi 5V level may be the problem.)