Analog or digital IR for proximity sensor?

Hi hi,

I was thinking of a project for home automation with few IR sensors on my stairs that detect when someone pass through and turn some LED on. I would like to build it myself so i didn't want to use one of those sharp or ultrasonic sensor.

After playing with few IR sensor, i realize how difficult it is to calibrate the analog one. When the sun pass through the windows, they become completely blind! I should probably try electronical and paper filters.

Then i made a test with a digital IR sensor TSOP38238 and i have a perfect detection of my remote control signal even with the sun on the sensor...

I need around 60 to 70 cm detection, should i work on analog IR with several filter or digital IR with a signal? I have to precise that i don't need any distance measure, just someone pass or not...

Thanks a lot, if you have other ideas or any question, don't hesitate :)


The modulated digital is the watch to go but don't use that sensor as it is not suited to a continuous pulsed signal. Go for one that is designed for a "light barrier"


I thought about light barrier, the problem is i am gona need one device on each side.

With those digital sensor, can't i send a pulse signal every 200ms and see when it detect something?

I am playing with the calibration right now, it s very impressive how those sensor can detect the signal all the time, even when i make a tube with dark paper around the LED and the reception...

the problem is i am gona need one device on each side.

Or a reflector.