I spent the extra long weekend tinkering with my Arduino modules, getting myself satisfaction now and then, and disappointments sometimes.
One of the modules that got me busy was the PIR sensor. I got 5 pcs of it online some time ago. Only lately did I have time to tinker with it.
As with a lot of Chinese-made clones bought online, the whole lot sucked.
Firstly, the PIR sensors sent to me was different from the advertised pic on the online seller’s page. Instead of the one with a jumper with which one can opt to use the ‘H’ setting or ‘L’ setting, I got the ones without the jumper. The sensor was fixed at the ‘H’ setting. But I only got mildly disappointed by this fact. After all, I wanted to use the ‘H’ setting more than the ‘L’ setting anyway.
Besides, i could always alter the setting by cutting the ‘H’ connection and shorting the L connection on the board itself. These 2 settings spell the difference between single trigger or repeating trigger.
|From this site :|
At the ‘H’ setting: “When a motion is detected, the output turns HIGH for the time that is configured by the time delay potentiometer like a single trigger but every motion during the time delay is detected and restarts the time delay.”
Long story short, I found that only 1 out of the 5 units worked satisfactorily. Meaning, only 1 worked as it is intended to be when the PIR is set at the ‘H’ setting. The rest either worked like they were set at ‘L’, or did not detect any thing at all.
The one working unit is not even that good. The unit is supposed to be able to detect up to 7 meters when the Sensitivity is set to the max position. But the farthest it can go is even less than 1 foot.
Update: Ok, I tested it again and it can actually detect up to 2.5 meters!
Of course, I have no electronics background beyond the very basics. It’s only because of my interest and the various youtube tutorials with which I am able to follow the procedures that allow me to act like I know anything about electronics.
So, for this case, the following youtube tutorials helped me proceed with the testing of the functionality of my PIR sensors.