YZIF MC-31B NC NO Optional Door Sensor Magnetic Contact Reed Switch 2pcs

I wanted to connect my ESP32 microcontroller to a door sensor, and voltage sent when door is open, but not when closed. This is easy to achieve with this magnetic sensor.

I needed an NC NO magnetic contact to work with my Meross Smart Garage door sensor which only comes equipped with one sensor. It didnt take long to wire one of these contacts up and everything worked a treat. They are good solid units which have yet to fail. As I only needed one, I have a spare for future projects.

They worked as described but unfortunately one of them failed on checking before installing. I suspect it was a dud (Made on a Friday). Replacements came within days of reporting the fault and they work perfectly as expected. A great service.

They work fine they just look and feel cheap. Biggest gripe is that the wire contacts are not covered on the top so live and neutral wiring is exposed if using lights for these which I am. For an alarm system the voltage is very low, I am using a 24v led driver so have had to tape it up to cover the contacts.It’s only meant for low voltage and amp ratings so really meant for alarms or door/window sensors instead of lights.The NO and NC took me a few minutes to get my head around (normally open and normally closed)I’ve wired mine in but I can’t remember which one I used, I just tried it until it worked.Not the cheapest to buy so there are alternatives to consider. If it’s going somewhere visible you will want a cover or a better looking one as they do look naff. Mine is in a cupboard so it’s ok.

This product so easy to fit also it can be dropped onto French doors without see ot .