I’m trying to figure out what I’m doing wrong with the tsop4838 IR sensor. I assumed you can just connect the pins directly (1->analong in, 2->ground, 3->5v[tried 3v too]), but it seem to hang at 5v. I then tried with a 3v source which again hangs at that voltage. I then place a 100 ohms in front of 5v/3v which had no impact. Each of these attempts was with a different sensor to avoid reusing a damaged sensor. Keep in mind, in all these cases, no IR sources were pointed at it, just the ambient light of the room.
Is there something I’m not understanding about the tsop4838 sensor?
Isn’t Pin 1 to the left with the bump facing you?
Shouldn’t I be seeing little to nothing (~0V) with no IR source in a lit room?
Please help, I’ve been stuck on this for a while… :o
Yep pin 1 (left) is OUT, pin 2 (middle) is GND, and pin 3 (right) is Vs (Positive). Max voltage of 5.5V, so 5V should be ok.
How do you know that it “hangs?”
Shouldn’t I be seeing little to nothing (~0V) with no IR source in a lit room?
No, the sensor is active LOW which means the OUT pin should be Grounded when it's detecting light. So when it doesn't detect any light (IR), it should have a positive voltage on the OUT pin. Have you tried it in a NON-lit room?
Ya… didn’t realize there was a band-pass filter, that would explain why I didn’t see any changes after pointing 8 IR leds at it… I’ll test that tonight. :oops:
Mr.UNOwen:
Ya… didn’t realize there was a band-pass filter, that would explain why I didn’t see any changes after pointing 8 IR leds at it… I’ll test that tonight. :oops: