Go Down

Topic: [SOLVED]IR emitter / detector pair for digital high low? (Read 1 time) previous topic - next topic


Dec 03, 2012, 05:00 am Last Edit: Dec 03, 2012, 10:05 pm by Riccarr Reason: 1

I'm trying to create a circuit for a IR emitter/detector pair so that when the beam is broken it will read as a HIGH on the arduino digital pin. I'm very noob to electronics, I'm a programmer and am more into the program development on the arduino and have no electronics background.

I have fashioned my circuit after this example of a tach/rpm counter.


I have that circuit working using the LED so that if I break the beam then the LED will light. But instead of lighting the LED,  I want to run that signal to one of the digital inputs to the arduino.

I want to use digital pin high/low, as oppose to analog pins, because I'm actually wanting to use multiple sets of IR emitter/detector pairs and run them into a parallel/serial shift register (74HC156) so that I can feed many sensor signals into the arduino. My understanding is that the shift register will want high/low signals and won't work with analog levels???

I have my programming working with the 74HC165 and tested with multiple push buttons and received the signals; now I want to replace those buttons with the IR emitter/detectors. I'm getting fluctuating and constants signals, I believe, because the IR is always sending some level of voltage on the signal pin which I presume causes continuous high signals?

So, can the IR emitter/detector pair be used as I am wanting, in the scenario I've described? And if so, how would the circuit be set up?

Thanks for tips/comments.



Actually ... I have it working now. While I was testing with the IR pair as one of my input signals, I also had several buttons connected as other input signals. It seems one of the buttons is faulty and sending continuous high value and leading me to a wrong conclusion. So, I have 4 buttons and one IR pair (as a testing scenario) and inputs give accurate high/low states. This is terrific, although I am surprised that IR is working this way; I would have expected the constant power from the IR pair to throw off the high/low state for that input pin.

Go Up

Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

via Egeo 16
Torino, 10131