Communication Arduino Due to Arduino Uno

I need to communicate Arduino Due to Arduino Uno during my search i found the I2C communication but the Uno work at 5V and the Due work at 3.3V, i want that the Due work like master and Uno like slave, some one can help me with this problem? Some one have a solution?


If you are sure the Uno at 5V is definitely configured as an open-drain driver (never pulls the signals HIGH), then in theory you can just put the 4k7 pull-up resistors from SCL to 3.3V and from SDA to 3.3V. The Uno will recognise 3.3V as HIGH and the Due won't see any voltage higher than 3.3V. In theory.

I haven't poersonally tested this and the consequences of making a mistake are a burnt-out Due, so I'd be hesitant to try it. There is probably a better way to wire things that incorporates protection (using schottky diodes and extra resistors) that gives peace of mind.