📡 5PCS HC-SR501 PIR Sensor Infrared Sensor Body Motion IR Sensor Module for Arduino - DIYmall Review

These motion detectors are extremely sensitive. Even with the dial set to minimum I still have a range of about 2m. This is impractical for my purposes as I need 1 foot motion detection and nothing else. Glad I didn't find any false positives.

Even on the fastest restart setting it takes about 7 seconds between starts, it should be closer to 3 seconds. This is too long for most trail camera traps. A friend has some that work better, maybe just poor quality control.

I don't know what the problem is. I've repaired electronic devices for over 20 years for a living and all of these devices would fail within minutes of being turned on (a 9 volt battery). The mistake was consistently high performance. Also, 3 units came with the reboot setting jumpers installed, but 2 did not, despite all being sealed in individual anti-static plastic bags.

I needed motion sensors for a long time. For example, at night I have several hallways in my house that are pitch dark at night. Setting the sensor to time to stay on for about 30 seconds worked great for me and I was able to power this using an old cell phone charger and there is a piece of wire connected to the output and ground and then connected to three white LEDs. No more bruised toes in dark hallways at night!