SHILLEHTEK HC-SR501 PIR Motion Sensor Module Blue for Raspberry Pi, Raspberry Pi Pico, Arduino, ESP32, and Other Microcontrollers

It just works. If you like to tinker and have some spare PCB boards around, throw this on. It's low power draw and sensitivity is great. I've put a little motion sensor together to automate some lights with Home Assistant. Good price; you can find cheaper, but it's not going to arrive with the Amazon-backed 30-day return if you get a dud. If there's an issue, I usually want to address it and get back to tinkering quickly, so I'm willing to pay a bit more.

As a few other reviewers have noted, a software controllable adjustment would be an improvement but would increase the cost. So, you need to provide access to the pots if you need to change the sensitivity. The delay you can do similarly programmatically but that means the device may not be able to sleep as much if you're running on battery.

This PIR sensor is exactly like the other dozen clones out there. Very easy to use. Outside pins are for 5v VCC and GND, middle pin goes HIGH/LOW. 2 pots to adjust sensitivity and timing, and a jumper pin to switch trigger modes (when/how the timer restarts). Since the GND/VCC pin labeling is covered up, look it up or just remember GND is closest to the switch trigger selection jumper. The big dome is just a lense to widen the field of view, so if it's too wide for your application, it's not usually an issue to partially cover it up for a narrower cone of sensitivity.There's a couple "hidden" features on these: there's a couple solder pins on the bottom to hook up a couple more sensors to help with accuracy. One is for a thermistor, the other for a photoresistor. Adding an LDR (photoresistor) is probably the one most people would choose to use because it helps avoiding triggers when the lights turn on or off. The other is to help with temp-related trigger issues -- it is sensitive to IR, after all.You're paying for convenience since it's basically plug'n'play, but even then, this is a little on the spendy side with zero functional difference from what I could tell to the other (5v) clones. However, keep in mind this is NOT a 5v/3.3v module. I did a quick test with an Uno and an ESP32 (w/a voltage divider to drop the output signal, pay attention to currents) and it worked as expected.

Great module with built in adjustment can be used for a wide variety of projects in this configuration and is accurate in my tests

The physical design is really nice and lends itself well to a custom enclosure. All of the components are mounted opposite the sensor and there are no parts or traces waiting to be damaged on the sensor side. It's a simple 3-wire connection (VCC, GND, OUT) and it has an on-board regulator to allow it to run off anything from 5-20V. The output is 3.3V, which may be problematic for some devices expecting 5V, but it was fine on my Arduinos. It also has a jumper for 1-shot or repeatable trigger and pot adjustments for sensitivity and hold delay.The only "nice to have" that I could really ask for would have been software control over the sensitivity and hold delays, but at this price point, that's an unrealistic expectation.In operation, it works reliably and without any issues. No special drivers or software required. It's a simple 3.3V on/off signal that's all configured in the hardware itself. If you've got a logic pin to connect it to, it's going to do the trick.

Simply packaging allows damage during shipping.The pins and some components are bent at an angle.The device is still functional.The device has an onboard 3.3 Volt regulator.It would be nice if there was a 3.3 Volt input pin along with the 4.5+ Volt pin.The trigger is 3.3 Volt when motion is detected.The device has two potentiometers, one for sensitivity and one for the trigger pin high duration.Also there's a jumper pin for the trigger mode.

You couldn’t ask for more in the realm of ease of use but there is definitely something to desire in over-all function.its analo, offering a simple on/off output instead of a digital or resistance variable output. This is greater for easy setup but leaves something to be desired if for example you want different responsiveness programmed in to your system at different times of the day. It does the job for me so I’m happy.

The module's a bit on the expensive side, but this is to account for its adjustability which is not typically present. The module is good for prototyping, to understand the parameters of what you want, though probably isn't what you'll want to order in bulk for your batch projects -- or maybe you don't care so much about price and will just use these; no judgment here. Module gave expected output in testing, and adjusting range/sensitivity is straightforward.Note the module does not support 3-4V in (at least in product description; I didn't think to test if it functioned at those voltage ranges regardless), so you will need to up voltage if using 1S LiPo/LiFePO4 or a stable 3.3V out and eat the conversion losses. The pin labels are also obscured by the ehhh, "diffusion dome"; that is, you can't see which pin is which without popping the dome off or guessing; but the dome comes off easily enough. With these caveats -- for what it is, it's a useful, well-made product IMO.