Optoisolator expansion board

Does anyone know how to code a nano to read an optoisolator expansion board?
Here is what I have regarding what I’m using

https://hacktronics.co.in/rs232485-usb-ttl-converters/4-channel-opto-isolation-module-high-and-low-expansion-board

Do you have sample code? Looks like an ordinary on/off use of Arduino pins to me

I do not. I’m not sure how to do the on/off coding I had simply been using the analogRead sample code.

acdavis1999:
I do not. I’m not sure how to do the on/off coding I had simply been using the analogRead sample code.

http://www.circuitbasics.com/arduino-basics-controlling-led/

I am wanting to use this as a control for an if statement. Do you believe this would work?

acdavis1999:
I am wanting to use this as a control for an if statement. Do you believe this would work?

Yes, go for it. The sky is your limit

Awesome, thank you!