Laserfinder helps to locate objects with reflexive surface (eg. silver safety appliques).
Finder is mounted on moving head which scans the surroundings. Finder consist of two main parts.
2) sensor - photoresistor with red lens. I used one from a gun from old "Shot the target" TV games. But any lens can be used. The red filter helps to see the laser in daylight. any red transparent foil can be used.
Sensor is connected to ADC input.
Head vith laserfinder is moved 180 degrees by 1 step. When ADC reading drops the position of servo is stored and recalculated to degrees.
I reccomend to use photoresistor with low value (10 - 50 kOhm). With 10k it works up to 5 meters.
In combination with ultrasound sensor you can locate the target very preciselly.