Trying to learn about the PI and I have acquired a pi Zero W with the GPIO header. I have an external device that signals activity via an LED, which blinks @ 1.8v 2X and then remains on until reset, which then drops to 0v.
I would like to have a small script running to text me 1x when the LED remains on. I have found suitable demos for this, but I was a little disheartened to learn the PI would not consider 1.8V high.
So, I understand I need to probably build some additional circuitry, maybe a opto isolator or just some sort of pull up/down for this. Can anyone point me to the right solution? The device I am monitoring is powered by a simple wall wart @ 9v.