RS422 to trigger Arduino Uno

Hello guys,

I have a electrical board that communicate throug a RS422 port. And I would like to trigger an Arduino Uno from this serial port RS422. The properties of the signal from this RS422 port is 38400 baud, 8 data bits, 1 odd parity bit and 1 stop bit.

I can use either a low or a high going pulse from 0 to 3V3 (using Tx+ or Tx- and GND pins from RS422). So it sounds compatible with the Arduino Uno.

I am now wondering which pins of the Arduino should I use to plug in the pins from the RS422 ?

Then, it comes to the programming part. After pug the cables in, I would like to call those specific pins. I was thinking of something like :

if (Serial.available() > 0) { code to run }

Thank you for any feedback.

Some notes:

  • What do you mean by trigger? Only see if something is send or receive what is send?

  • RS422 has a max voltage of 6V and normally relies on the impedance of the line. Just adding an Arduino will a) be dangerous for the Arduino because of the 6V and b) will mess with the impedance. Also, RS422 can be lower then 6V (even a volt) so that makes it not possible for an Arduino Uno to trigger.

So I would just use a RS422 receiver IC and let it do the RS422 part. And you can then choise to really read the signal (via Serial or SoftSerial) or just use it as an input to trigger on every frame.