On the subject of the IR leds, I may have missed it, but how is OP producing the 38kHz carrier?
I'm wondering why you're using a carrier at all: what's wrong with an ir led which is just solid on when it's unbroken, sensed by a simple photodiode?
That said, and given you're thinking carrier already, would it be worth exploring modulating the 6 outputs uniquely so that each sensor is only reacting to its own transmitter. Then they can all be on all the time. (That's an off the top of my head thought. It won't be difficult to modulate the signal, but I'm not sure how big a deal it will be to demodulate it at the receiver.)
So I should look for an Arduino which has at least six output pin since each LED should connect to one output pin?How about the sensors, each of them should connect to one pin of Arduino and also six pin is needed, right?
It won't be difficult to modulate the signal, but I'm not sure how big a deal it will be to demodulate it at the receiver.)
Yes, but most Arduinos have more tha 12 pins available.Try to get one set working first.The tone command could be ok for testing.Leo..