Hey guys,
Haven't been on this thread for a while, but I've come up against another problem.
My TSOP34138 ir receiver module acts strangely.... I can have it facing an ir transmitter, emitting 38kHz ir, and it won't output a LOW, and when I move my hand in front of the transmitter (as if to block the transmission and cause a reaction from the TSOP34138) nothing happens, the TSOP continues to output a HIGH. But, when I cover the TSOP with my thumb for a number a seconds then remove it all of a sudden it starts responding to the ir transmitter - it will output a LOW when it detects 38kHz ir, and a HIGH when I block this ir. Why is this?
I have hypothesized that my TSOP is the wrong type of ir receiver module for my 'break-beam people counter' application, because it is designed as a TV remote control receiver (where it is waiting for the occasional burst of 38kHz ir). My application is the opposite in a way, because it is CONSTANTLY receiving 38kHz ir and is waiting for the occasional break in the ir beam. In the TSOP data sheet (attached) it says on the first page, under Application Circuit, that the output voltage shouldn't be kept under 2V by the external circuit. In my application the constant 38kHz ir is keeping the output voltage under 2V, is this doing exactly what the data sheet is telling me not to do?
If I am using the wrong receiver, then why, in this tutorial I found for a break beam counter, is it recommending the same TSOP receiver?
Cheers for your help.