Raspberry Pi Serial

#1

Hi, I am very new to Node-Red but I have red all the documentation I can find and I am still confused. I am trying to use an arduino (the adafruit trellis m4 express) hooked up over a serial connection to my pi running node-red. I would like to read the input of the serial monitor on my pi and detect what button is pushed, however my problem is I don't understand the trigger for node red.
tl;dl: I don't understand how the serial nodes work in node-red and I couln't find any documentation to help
Thanks

#2

The only tricky part is knowing what "device" your serial connection attaches itself to. There are various ways to discover this if you need to - a quick Internet search will lead the way.

Assuming you can find that, all you do is add the serial-in node then double click to get to the edit properties. and add a new serial port:

Configure that to point to the serial port you are using. This is quite a common setting:

I have 2 serial inputs on my live Pi based home automation system:

The RFX node also uses a serial connection.