Connecting Arduino Uno and Due with UART

Projects Networking, Protocols, and Devices
1

Is it possible to connect two Arduino's, Uno and Due using UART serial ports?

Would the diffrent operating vollage levels be a problem? Due runs on 3.3V and Uno runs on 5V, would this diffrence damage my Arduino Due board? I am thinking that it would not since Arduino Due is connected to a PC via the UART which is also 5V.

2
  1. Yes. Maybe not with direct wiring tho. Could add MAX3232 to each to buffer the Serial ports to comparable levels.
  2. Yes. Running 5V TX from Uno into 3.3V Rx on Due would be an issue.
  3. Yes.
    Due & Uno connect to PC with USB, not UART. Unless the Due can act as a USB host, it cannot talk to the Uno which is a USB slave.
3

You need a simple resistive divider from the arduino's TX to the Due's RX.
Then from the Due to the arduino you need a single transistor inthe common base mode.

4

I have tried to directly connect Serial of Arduino Uno to Serial1 of Arduino Due, while the Due was connected to my PC using its Serial.

It did not burn any thing, and I was able to communicate to Due via Serial Monitor of PC, and then to Uno via the Due.

But this may cause a problem in the future so I will do something to reduce the 5V of the Uno to 3.3V.

Thank You!