HC-SR501 PIR Infrared Sensor

After a couple of decades, I decided to build some new life size figures using some of the latest sensors, relays, and motors. I'm using the HC-SR501 sensors to initiate the animatronics, and found a couple of issues. They work w/o issue, and will continue their use. I also wanted to incorporate a flame bulb that will go in the medieval torch I built out of PVC pipe/fittings, EVA foam, and modelling paste.Regardless of the input voltage, the HC-SR501 output trigger voltage is only 3.3V-3.4V DC. This means I can only use 5V DC opto-relays, instead of 12V opto-relays as their trigger voltage is >4.5V DC. This required making a 5V circuit to power the HC-SR501 and the relays. The video shows the DC-DC Buck converters (blue LEDs) and the 5V DC opto-relays (red LEDs) driving the HC-SR501, one motor, and the flame bulb. The simplified schematic shows the wiring layout I made with applied voltages.The second issue to note with the HC-SR501 is the delay pot. It only takes a 10 degree turn of the pot to go from the minimum delay time of one second to 25 seconds.Their sensitivity is very good. I have yet to try adding a thermistor to the HC-SR501 to test its night time capabilities.FYI: I'm using the B0CMXCZX9Y nylon standoffs (via Amazon) to mount all of these boards.UPDATE: I'm holding back from installing a thermistor. Low light sensitivity is excellent.

As per the HC-SR501 data sheet, stops detecting ("detection range is shorter") as temperature approaches 30 degrees celsius (approximately 90 degrees fahrenheit). These units have the through-holes to add a thermistor to improve high temperature performance, if one has a thermistor to add.The real test is if starts detecting again when the temperature drops. I plan to drop my score one star for each unit that permanently fails on me.Worked just fine the first three days I had it connected. Easy to set up. Pins fit well into female Dupont wires for prototyping.

I set up 2 different doppler motion sensors using these HR-SC501 PIR sensors, one using an Arduino microprocessor and one without. Both worked as advertised, tho the range and sensitivity with the Arduino was much better.

So my fiancé had the idea to have a Shrek themed party and I thought it would be a great idea to have a speaker yelling at people 'WHAT ARE YOU DOING IN MY SWAMP'. So I bought these PIR sensors and hooked them up to my Pi 3 and programmed it to play a sound on detection. These are very sensitive so I recommend hiding them so they can only sense one direction.

Hooked up to 5V supply, output toggled from high to low as the description says, tweaked the pots on it to play with it, they work also. Now to figure out what the heck I want to use these with, I bought them for Halloween stuff.

Bien

Received this five pack of PIR sensors and, although the pin out is clearly shown on the listing, the boards I received were not marked at all. The photos show nice clean labels. The real boards arrived with absolutely nothing. If you handed one of these to a friend without directions, they would have to guess. If you tossed one on a student’s desk in a science class, they would stare at it, stare at you, and probably decide the project was a trick question. Without any markings or instructions, you need to already know exactly which listing you bought and then go hunt down the correct pin out.This is one of my biggest pet peeves. No manuals, no instructions. Not even a tiny slip of paper with a URL or a QR code. The packaging was completely nondescript. Just an Amazon label and some sensors inside. It felt like opening a snack bag and discovering someone forgot to put the snack in.Before I even tested them, I wanted to get this part written down. If there is a problem during testing, Amazon gives me an easy exchange, so no pressure there. The good news is that the sensors do use the standard BISS0001 chipset, so there is nothing mysterious inside. The capacitors are nice and beefy, the modules look well built, and you cannot really argue with the price. A quick visual inspection shows decent quality and no alarming surprises.After pulling up the spec sheet from the listing, I wired one to my Raspberry Pi 5 using the GPIO pins and ran a few quick motion detection scripts. It worked flawlessly. Sensitivity adjustment worked from about three to seven meters. The timing control worked from about three seconds to five minutes. It actually detects motion, which is the entire point, and it does so reliably. Three wires, a Pi 5, and now you have motion sensing. I also appreciate the simple jumper for single trigger versus repeated trigger mode.Overall: The hardware is solid, the price is fantastic, and the performance is exactly what you expect from the classic HC SR501 design. The total lack of labeling or documentation drags the experience down in a way that is completely avoidable. Three stars from me. Add markings or a tiny info sheet and this would have been an easy five.

I used one of these for my Pi based Magic Mirror project and it works well. Build quality seems good and I’ve had no problems so far!

These sensors did exactly what they were supposed to do. they were easy to hook up to an Arduino and use in a sketch.

very pleased, arrived on time, everything works

I haven't used them yet sorry

When I received the product I immediately connected the PIR. The output was 3.5 volts regardless of the input power. I assumed this was a defect in the product. NOT THE CASE. The product works great and the setting are very good. You can set up the output to stay on for 5 sec to 5 minutes. In my case, that is exactly what I needed

I like the radar sensors even better.