I’ve been using the Monoprice Z-Wave recessed door sensor, but its operation becomes unstable as the battery ages. I’ve been searching for an inexpensive ZigBee recessed door sensor for years, but no success. So I decided to see if I could make my own.
What I found small enough was the Visonic MCT-370. Only $16 on eBay. I removed it from its housing and utilized the housing from the Monoprice and modified the battery holder from the Visonic. You can use any similar size tube other than the Monoprice housing, but I already had it available.
I used a rotary Dremel tool to carve down the Visonic battery holder to a size that could barely slip into the drilled-out door hole that I had made previously for the Monoprice sensor and then glued the modified battery holder and shortened Monoprice empty housing together.
I tried to desolder the glass reed switch from the Visonic so I could reposition it horizontally at the top of the Visonic pcb, but when I tried to solder wires from it to the original Visonic pcb pads, the tube broke. It’s not the first time I’ve damaged a delicate glass reed switch, but if you don’t try and bend the leads, it should be ok.
So I used the non-glass reed switch from the Monoprice instead and a plus is that it is way more sensitive than the original Visonic glass reed switch and doesn’t require horizontal orientation! You don’t need to mount it horizontally at the top of the Visonic pcb since it is so sensitive. I mounted it vertically where I found room on the top of the pcb. You might be able to mount it where the previous glass reed switch was located because it’s so sensitive. The non-glass type reed switches are real cheap on eBay if you need one. If you don’t break the original glass reed switch and can successfully relocate it horizontally at the pcb top, then the above is unnecessary.
I also wired soldered the plus/minus terminals from the modified battery holder to the Visonic pcb pads.
I also reamed out the original recessed wood door hole about a 1/16 inch to make the whole assembly a bit loose to make sure I could easily remove the assembly for battery replacement.
I drilled a hole at the top of the modified Monoprice tube housing so I can extract the assembly with a small hook tool.
Here’s come pics:
It pairs as a “thing” which you can rename and then use SmartSense Open/Closed Sensor as the type and it will provide Open/Close, Battery status and Temperature.
So far, it’s working fantastic and I should even experience much longer battery life than the original Monoprice Z-wave recessed sensor.
This is my first project post, so I hope someone finds it useful. The work is a bit sloppy, but I was in a rush and it only took about three hours to complete (not including JB Weld dry time). The next one will be cleaner.
