Hi All,
I've seen a destructive tear down before on these new Matter door sensor devices but no info on modifying them. I want to use a remote switch - micro/reed/whatever contact given how cheap these units are they're ideal but the sensor is too big to mount where I need it so here's a rough guide on adding wiring.
First, getting the sensor apart does damage the casing, no way to avoid it, though if you're careful it will go back together maybe with some tape or glue. You want to protect the battery compartment to so it mounts nicely as originally to make life easier in the future.
Take the back off, battery cover off and remove the battery. Take a pair of pliers and squeeze the battery compartment around the middle and you'll see the lip of the top cover. Get your spudgers in and carefully unclip it. The following images show what the case looks like, you'll also see it's mostly intact 
The PCB unclips so do this carefully, this is what it looks like on both the front (switch/LED side) and the back:
Onto the modifying..... The Myggbett uses a surface mount 6323D Hall Sensor in an LH Package, the schematic looks like this, and we're interested in Pins 2 (OUT) and Pin 3 (GND):
It's located on the back side of the PCB here:
Pin 2 and 3 are highlighed here:
Carefully solder wires to each of the two pins, re-assemble and notch the case for the wiring to exit the casing and wire up to whatever type of switch you want to use. You could de-solder the hall sensor but not sure it's necessary given the magnet will be out of range configured this way. That's it!
Happy Modding!
