A3144 Hall Effect Sensor 3Pins Magnetic Detector for Arduino (Pack of 20 pcs)

I don't think I noted the voltage range (4-24v) when i purchased these to work with my 3.3v logic board, but luckily they still work! Perhaps it changes the sensitivity characteristics or something else, but it works great for my purpose.I have 2 of them connected in parallel for an "emergency stop" function. In normal operation, magnets are in place over the sensors, maintaining an open drain and LOW signal pin. Only if BOTH magnets are removed from their slots (via a pull-cord), the signal pin is pulled high by the pullup resistor, signaling an emergency.

Almost an exact replacement for an RC airplane DLE 20 engine electric onboard starter pickup device. The wires broke on the original one. It was a simple matter to heat the epoxy holding it in place and removing it. Wired a new one up and epoxied it in place. Fairly easy job, and a whole lot cheaper than a new starter. I would imagine this would work for most gasoline RC engines.

I've tried two of the 20 sensors so far and I can't get them to register a signal when I pass a magnet. Might be me though. I tried a few different magnets from my fridge, so maybe they weren't strong enough, or perhaps I wired it into my breadboard wrong...I did get false positives when the magnet ran along the data cable (which created a current). I also think we got some false positives based off static, because it would go off when I had two cables connected together and ran my hand over the air in that area. And I also got a signal read when my fingers accidentally touched the power and data prongs.I've kinda given up at this point, especially when I realized the thing I was told they could do was inaccurate, so I'm buying physical switches instead.For reference these are supposed to detect a magnet, either the +/- side (sometimes both sides), from the side of the detector with the numbers on it (3144). It is a digital output (meaning you can't calculate the distance of the magnet to the sensor). I've assumed it would output 1/HIGH when a magnet is near, but I just read it would read the inverse, so 0, and 1 or HIGH by default. I didn't see results to suggest this.Also wondering if it could be due to the closeness of the pins at the bottom, the standard breadboard and connectors stretched these wide, but I had seen YouTube videos demonstrate them this way so assumed it is okay.I wouldn't recommend this brand/product, but I also wouldn't trust my credibility as this is apart of my very first Arduino project. If I need this sensor in the future I would consider the pre-soldered boards with led indicator as I suspect they are easier / less likely to have problems.Fortunately these were fairly cheap and small, so I'm just going to hold onto them in case I ever figure out how to use them properly, or find another use.Message to the seller: more information on the product page could have helped, I really appreciate when a component shows an example use case, and basic information...everything on this I had to look up online and in YouTube videos about the 3144 sensor (note there are lots of different ones, which I wasn't aware of at first).Last note for buyers: if you think this will detect metal, it will only detect magnets... my goal was to detect metal balls that rolled by, and a very dumb ai (chatGPT) told me that it detects disruptions in the magnetic field which meant it could detect metal balls...just a reminder that ai is way dumber than we realize, and worse, it is super convincing with its confidence.

built this elaborate busy box for my grandson with just under 20 of these sensors. Each one is flawless and durable. Paired with small magnets and covered with epoxy then connected to arduino. Perfect. Just remember they do have a polarity so be sure to have the magnet positioned to trigger the sensor.

Pretty good for the price. Detecting up to an inch away with just a small neodymium magnet.

Nice little set used for ironman helm 3d printed and magnetic open switch this worked out great for me.

I do recommend it. Motor running smooth. So go for it.

Not sure to chock it up to user error or not a great product, hence three stars. Sensitivity seemed off.