comunication between two arduino.

Hello, I am trying to make two arduino's comunicate. But here lies the problem how do I do that?

I have tried it with an if statement like: if ("go")){


I want to trigger one arduino's code by sending over serial a "triger"

The one problem I have left is that on the one arduino that need's to trigger the other I've only got two pins left, and those are the rx and tx pins:) any help would be appreciated.

if ("go")){

And where did you find that form of the "read" method?

This subject comes up every other day - do some searching.

The read method of the Hardware Serial class accepts no parameters. Take a look at this page .

Yes I know this doesn’t work :slight_smile:

it’s just an example of what I want to achieve,
that the program start when it reads a trigger from serial.

But I just realized that this can be done way simpler/easier.

by just pulling a pin high on one arduino and let it be read by the other ,
If pin input high → trigger sketch.

so sorry for posting a useless thread?

You said you'd run out of pins.

Also be aware that serial communication is not instantaneous - make sure your application can cope with the inevitable latency.

yes this is true got no pins except for pin 1 and pin 0 ... but I gues it's only one pulse so it can't hurt?

Be sure there is also a ground wire run between the two arduinos, and that both sketches have a Serial.begin() at the same baudrate.

This should help you get started:

//I have tried it with an if statement like:
if (Serial.avalible > 0)  // has one or more characters arrived?



This works thank you :)