Are you trying to use the collector voltage as an analog signal that
indicates the degree of alignment of the two parts?

If so, I suggest you look at using the TAOS TSL230BRP detector. This will
give you a digital output that you can connect directly to a PIC pin.

Using a simple photodiode and phototransistor in this mode will be
difficult. In any case, your collector resistor could be much higher..
perhaps 10k.

Are you trying to measure degree of alignment, or simply a binary signal..
aligned, or not aligned?


Neil
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