PIR Motion Sensor Modules, Mini Pyroelectric Human Motion IR Sensor Detector(12 Pack)

I'm watching my memory scope now while I have this thing hooked up.It seems that the output is normally low and goes high for about 5 seconds if presence is detected.This is very useful, because just by adding a capacitor you can distill either an active low or active high pulse from this. And that makes it useful for applications where you don't even bother using a microcontroller.

The media could not be loaded. These PIR sensors were very easy to use. They are logic 'low' when sensing nothing and then go 'high' (about +3.3 volts in my testing) when triggered. Very little voltage draw when idle. I am using these to trigger a pin interrupt on an atmega328p. They have been the most reliable part in a halloween prop I've built this year. I tested through a 10 meter shielded cable and it was still able to trigger an interrupt. This will allow me to place the PIR sensor a good distance from the prop.One 'bug' I encountered was kind of interesting. I put some brand new 4xAA batteries in my prototype battery holder, along with some other changes I made to 'harden' the board. My PIR stopped work. None of the five that I got in the pack would work. I was bummed and stumped for a bit so I started some diagnostics. I saw that the triggered PIR was sending about a +3.3 volt signal. The new batteries however were supplying the chip with ~6.5 volts. This was too high and the +3.3 volt was no longer reaching the threshold of 'high' to trigger the interrupt. 6.5 volts is over the max specified for the avr atmega anyway. I added a diode in line (in series) with the power supply to knock the voltage down by about 0.6 volts. After this everything was right with the world again

I've used these in many project. Very small and versatile.The 3v power requirement is perfect for Arduino projects.

I've tested and used one of these sensors already, and it worked well. Onyehn could have made things slightly easier and included the product specifications on their product page including the output current and voltages and the power supply range and polarity.

I use a small raspberry pi zero w to power a monitor in our kitchen for a family calendar/weather board. I wanted to attach a motion sensor to turn off the screen when no one is in the room. My first attempt used a HC-SR501 style PIR sensor, but I ran into constant false positives there. This Onyehn sensor promised some better resistance to interference. A day+ in and I've had zero false positives so far. (I have it blipping data into a MQTT server that tracks everything via Home Assistant). Really happy so far.

The good news is that these worked at 3.3V directly so they're perfect for a NodeMCU running ESPeasy. The bad news is that they're soldered horribly - even I could have done a better job. Out of the 5-pack,3 worked, 2 didn't. That brings the cost per (working) device up a lot.

Garbage. These units had horrible solder joints. Just installing the sensor the sensor solder joints failed and diconnected. Do not buy.

UPDATE. : Now that I have time to actually test this thing, here it is: OUTDOORS, 86 degrees 40ft. powered by 9 volts. I can't say enough. I'll try to make a video.