Im in need for a proximity type sensor that has a range of minimun 2 meters, work outside in daylight, and needs to detect if something passes in front of it quickly. specifically i want to detect wether a person passes closely to the sensor.
As far as my research has gone it seems my (reasonably priced) options are some sort or IR or Ultrasonic distance sensor. IR sensors dont seem like they will have quite the range in daylight, but should be able to very quicly detect if something passes in front. Ultrasonic sensors should have the range i think, but im not sure if it will be able to detect a change in distance quick enough (? with controlling for signal noise and all that stuff).
What would my best choice be? Response time for the sensor to detect something for perferable be less than .1-.2 seconds.
endurs:
Im in need for a proximity type sensor that has a range of minimun 2 meters, work outside in daylight, and needs to detect if something passes in front of it quickly. specifically i want to detect wether a person passes closely to the sensor.
As far as my research has gone it seems my (reasonably priced) options are some sort or IR or Ultrasonic distance sensor. IR sensors dont seem like they will have quite the range in daylight, but should be able to very quicly detect if something passes in front. Ultrasonic sensors should have the range i think, but im not sure if it will be able to detect a change in distance quick enough (? with controlling for signal noise and all that stuff).
What would my best choice be? Response time for the sensor to detect something for perferable be less than .1-.2 seconds.
With an ultrasound transducer you'll need to fire off pings at a sufficient rate - however too fast and they interfere with the next ping, but I suspect 20Hz rate ought to be doable.
Ultrasound should do indeed, but clothing may not reflect the signal well.
The RCWL0516 is another option, subject to the overall environment (it needs sufficient objects that disturb its radio waves in its vicinity to work). It'll detect a moving person - or the cat, or a passing bird - just fine.
A person walking by is slow. When you said "very fast" I was thinking of small falling objects, or a speeding bullet. That's fast.