DRock,
You mentioned earlier,
Also, are you going to have each transmitter facing the receiver? Are all of the sensors and the receiver remaining stationary? IR is extremely directional to my knowledge, especially over long distances.
If you want to go simple, you could get you hands on some cheap TV remotes and use them as your transmitters. When sensor #1 is tripped, short a contact for the number one on the remote, number two for sensor #2, and so on. Then have a BS2 or PICAXE decode the signal.
I think you could still get away with a single 555 as well. In astable mode, you set the high and low pulse with a couple of resistors and a capacitor, so as long as the pulses are different enough from one sensor to another that your uC can tell the difference, you should be fine. Again, this is untested theory, so I may be wrong.
You mentioned earlier,
Now my personal experience with IR is quite limited, but I made a simple two-digit counter that was incremented by the press of any button on a standard IR TV remote control. The max range was about 35 feet. Beyond that the receiver couldn't detect a signal. Above you state 50 yards, so if you really want to explore this option, I suggest making a single transmitter and receiver with a single pulse or pulse train and see if it sends and receives the distance you want in the environment you want - indoors with fluorescent lights or outdoor during the daytime for example. The enviroment will play a role in the range. I suspect this option won't give you the distance you originally mentioned, but you may be able to increase therange by amplifying the signal somehow.I am trying to set it up so that I can have anywhere from 5-7 possible switches 50 yards or so away from the main base that will transmit a signal to the base when the circuit is completed.
Also, are you going to have each transmitter facing the receiver? Are all of the sensors and the receiver remaining stationary? IR is extremely directional to my knowledge, especially over long distances.
If you want to go simple, you could get you hands on some cheap TV remotes and use them as your transmitters. When sensor #1 is tripped, short a contact for the number one on the remote, number two for sensor #2, and so on. Then have a BS2 or PICAXE decode the signal.
I think you could still get away with a single 555 as well. In astable mode, you set the high and low pulse with a couple of resistors and a capacitor, so as long as the pulses are different enough from one sensor to another that your uC can tell the difference, you should be fine. Again, this is untested theory, so I may be wrong.