I have recently purchased a whole bunch of the 4050 Pololu Digital Distance Sensors as they seem to be the holy grail of object sensor that I have been looking for! I built some interactive games that detect balls being thrown through holes in a backboard and always had trouble finding a reliable sensor to detect the object.
I started with a 2-part “beam-break” sensor but the wiring was messy with the emitter on one side and the detector on the other.
Then I switched to a reflective IR sensor (same basic tech, but the emitter and detector are next to each other) but the cheap non-modulated sensors I was using were completely useless outdoors (Sunlight) or in certain indoor lighting situations (Fluorescents, etc).
Then I found the sharp sensors / carriers from Pololu which seemed great at first (Fixed the ambient IR problem as they were modulated) but I would get random “detections” when I had multiple sensors going at the same time - first they seemed “electrical” I was advised to add a parallel capacitor to the power lines for each sensor - it helped but I was still getting false triggers. (I think it was having many sensors in an enclosed space which was causing random triggers - I was never fully sure.)
But alas, the Pololu Digital Distance Sensor (using the 5cm version, #4050) seems to be working exactly as I need it to! Eureka and thank you!
My question is, how do these work?
What I mean is, how are these “LiDAR-based” sensors different than the standard “IR-based” sensors (such as the Sharp sensors). It is my understanding that these also emit some king of modulated IR light and detect it just the same, but they seem to work just fine exposed under direct Sunlight (I tested) and do not seem to be suffering from (that I think were) random IR reflections from inside my enclosure.
My understanding of LiDAR (which isn’t much) is that there is a rotating beam of laser light that is then picked up by a camera or other sensor and the distance of each point of light is measured (time of flight??) to determine how far away objects are. But clearly these sensors are much simpler than the LiDAR we used to see spinning on the top early-prototype self-driving cars, so I am also wondering what makes these “LiDar-based?”
Thanks in advance for the education!