I bought these photo-diodes, or resistors - I can not remember since I forgot to label the bag. I think I just bought some general purpose ones to get me started. They look like this:
I want to aim my 5mw 5v 650nm RED laser diode at this a short distance. I want this light sensor on my digital-interrupt pin on Arduino to toggle hardware interrupt, when red laser is on target with this sensor.
BEFORE I guess and destroy my hardware, I wanted to ask here if I am doing this right.
I was going to put a 100k pot on the resistor, in series. +5v->100k pot->photo sensor->ground. I test the voltage and see where the sweet-spot is when I am aim laser for this to show +5v signal. Tie that line into pin D2 or D3 and then be done with this.
Do I need to bring in an opto-coupler or some other component into this circuit, or will this simple design be sufficient?