IR detector testing

woody363

I'm trying to get the "infra red detector" that comes with the propeller education kit working.

I set up the detector as per the diagram in the Labs book, only without connecting the output pin to the chip. I have tried to detect the signal output with an oscilloscope under natural light, non natural light and the included IR LED and im yet to get even the slightest blip on the screen of the oscilloscope.

there is an IR photo transistor also included in the set that produces easily detectable signals under all of the above light sources.

I feel like i might be missing something, its either that or that the detector simply doesnt work, any suggestions?

Thanks,
Woody

erco

That detector only detects IR pulsed at ~38 khz. Point your TV IR remote at it and you'll see plenty of activity.

Mike Green

The IR detector that comes with the PEK detects modulated IR (at approx. 38KHz). It will not respond (as you've noticed) to steady IR or IR modulated at frequencies far from 38KHz. The "IR Remote for the BoeBot" tutorial has a diagram on page 191 showing a modulated IR transmitter using a 555 timer which can be used to trigger the detector.