I have a relay attached to an Arduino Uno which I want to control using my raspberry pi 3b. And yes I know it can be done by attaching the relay directly to Pi but I cannot do so. Don't ask me why. That is why I want to know whether it is possible to use Pi's output signal as input for the Arduino or not. I do not have spare parts so I don't want to experiment. If anyone knows about this, please tell me.

  • What type of "signal" do you want? A simple pin, that can be set high or low from the Pi? Or a real data connection like Serial (UART)?
    – chrisl
    Jun 1 '20 at 9:22

This way is fine: the Pi is a 3.3V based board, so connecting one of the GPIO pin from the pi to an Arduino will not damage it. Furthermore, the 3.3V are sufficient to be considered as HIGH even on a 5v Arduino like the UNO.

The other way around: connecting the output of a 5V Arduino to the input of a pi, will very likely damage the raspberry Pi!

So beware of your Pinmode before doing such a connection!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.