Datasheet for the TCRT5000 reflective optical sensor in its 8H variant as named, a 163 KB PDF. The TCRT5000 pairs an infrared LED with a phototransistor behind a daylight-blocking filter. The document gives the pin layout, emitter and detector ratings, and response versus distance. Typical uses are line sensors, tachometers and proximity detection modules. When diagnosing a module, measure the LED forward voltage, check the comparator threshold, and keep the sensor within its specified working distance.
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