Hi BillO,I really thank your information. In my case, I imagine first I need to know a little bit more, I only need to measure "the interruption". But as you say, power need to be considerated¿ The entrance where the door is located, only has 2 or 3 meters.... I understand there will be two parts, the transmitter and the receiver, right¿Thanks so much,LyonJK
This project does something similar, It has an IR Transmitter fitted and the Arduino looks for the presence of the IR to count a lap
Seems to be the wrong link? It's about controlling multiple servos from a RC transmitter.
These also work well for detecting people going past: http://www.ebay.com/sch/i.html?_nkw=arduino+ultrasonic+sensor(plus you only need one set of wires).
If I understand you correctly, knowing that someone opened the door is already good enough.How about using a reed switch like the ones found in most alarms?They are easy to install as they are meant for the job, cheap as can be and also easy to use with an arduino, as it acts just like a switch.See for instance http://www.hw2sw.com/2012/09/07/connecting-a-magnetic-reed-door-switch-into-arduino/, but there's probably tons more to find out there.
Hi LyonJK,IR would also be as simple in terms of programming I guess, just a bit more tinkering to do on adjusting them properly.However, I don't see how this would solve your problem.If you open the door for someone, like a messenger, either you or the messenger (or both) will still interrupt the IR beam, also registering as a false entry / exit...Only valid solution I can think of is using two beams a meter / 3 feet or so apart, and measuring timing and direction.Something like:Beam A is nearest to the door, Beam B furthest, both in your hallway.If B is triggered first, then A and nothing triggered after that for a couple of minutes: exitIf A is triggered, then B and nothing triggered after that for a couple of minutes: entryAnd make a filter for all other patterns (for instance, multiple readings of the same trigger, without the other in between count as simply one).I think this should work for at least a single person going through the door.If you have multiple people walking out / in the door after each other, you would probably need the last two readings from this setup to deal with direction...So I would expect IR to be technically simple, but to deal with also detecting the difference between just opening the door and really leaving / entering, the main challenge would be in the software, not the hardware.Regards Dennis