Hello, I'm working on making a school project that uses a motion sensor tied to an Arduino unit. However, while testing the combination of the two with the PIRsense code, I've run into a slight problem.
http://playground.arduino.cc/Code/PIRsense
Whenever I try to run the above code with my current setup it immediately begins to detect motion after calibration; which is denoted by the serial monitor displaying a "motion detected at (time)". The issue is, it never seems to stop detecting this motion or go into a low state. This is evidenced by the led I have tied to the output pin on the protoshield (the led does work fine, I've tested it) never turning off. I've tried to leave the room during calibration, leaving it alone in a small, cold side room that we have, getting it as far away as I can from the computer and more to no avail. I've even tested it with another PIR sensor that we got in the same shipment with the same results. Any help would be greatly appreciated.
Quick edit- I'm having trouble uploading the pictures of my setup I took earlier, I'll attempt to upload them again in a few hours.
How is the PIR output connected? If connected from input to Gnd only, you are probably picking up electrical noise. Put a 10k R from 5v to the input and PIR to Gnd. The input will be held high by the R until the PIR switches to Gnd.
You can also use internal pull up resistors (use the search box at top of page).
Weedpharma
First of all thanks for replying! As of the circuit, The PIR output is connected to 3. I'm going to try to put a 10k on it when I get a chance, but I've already gone home for the week so I don't have access to it till the end of the weekend. But setting the PIR to ground may have been the problem, I'm beginning to think I've wired this up all wrong. Either way, thanks and I'll get back to this.
Depending on the particular PIR, it may be a switch output or a voltage level change.
Please supply a link to the sensor you are using.
Weedpharma
Alright so here is the link to the sensor I'm using:
as well as a link to their site: http://learn.parallax.com/KickStart/555-28027
I really wish attachments on these would work because I have pictures of the setup, but now I'm worried something may be wrong with the PIRs I used. Maybe I messed them up when I did the wiring set-up? Anyway, I'm going to what you suggested and see if it works.
This has a voltage level change. The output is LOW (Gnd) when there is no movement. When movement is detected, the output switches to a logic HIGH.
Your program would need to monitor the digital input pin and detect a change from LOW to HIGH.
Weedpharma
Alright! I finally got it to play nice with me. I attempted to use the setup that this guy: http://www.instructables.com/id/Arduino-Basics-PIR-Sensor/?ALLSTEPS had up and now it's correctly flashing itself on and off. I'll still have to tinker with the code to fine tune some bits of it; but now that I have the base it'll be a lot easier to build.