Homebuilt IR Emission Detector
Although not a PIC project, it was built in my lab, and it was used in conjunction with my IR Remote project that is described later. On the left of the box is a hole which allows IR radiation to enter the box. Behind this hole is a phototransistor that captures this radiation, and controls the current to the LED. So as the IR radiation gets stronger or weaker, the LED brightness raises and lowers in step with the changing strength. This gives me an idea of the intensity of the IR emission. If I were to add a meter of some sort, I could get a relative visual reference to go by, which could then lead to a calibration of the readout. This would allow for a reasonably accurate gauge of IR Intensity.
My Homebuilt IR Emission Detector