Hey,
I'm planning to use a grid of IR diodes to measure the position of one IR emitter. My idea is to wire up the diodes to the A/D converter of a PIC microcontroller, and scan over the diodes in the grid in rapid succession, measuing the exposure of each. I'm not sure if I need to amplify the signals. Maybe feeding a low reference voltage to the A/D is sufficient? The emitter will be quite close to the diodes, around one inch or less. I imagine a 4x3 grid with the diodes one inch apart or less, mounted on a board together with the PIC. I figure that I'll be able to measure great enough of a difference in voltage between the diodes to track the X/Y position of the emitter fairly accurately (I have already scoured data sheets and found diodes + emitters with wide and even emission characteristics). The idea is to use an algorithm to calculate the emitter's 2D position down to a millimeter or less, using four diodes at a time.
I figure that if I can calibrate the electronics properly, do some low pass filtering to get rid of noise, and work out the maths, this is entirely possible.
Will this work?