I am non technical but I have 8 wirsbo stats in my house. One of them is faulty and the unit is now obsolete. Is it possible to purchase one of these pcbs and use it to replace the one in the faulty stat ?
The choice of MOSFET can be tricky. Seems that irlz44n was discontinued so you may need to find one adapted to the voltage and current you want to handle.
In all the cases you need to get a logic MOSFET too, meaning that they are fully open usually around 1 to 3V.
Also I'm sort of confused as it seems to me that L7812CV is a Voltage regulator, not a MOSFET. So if you are actually using that in the MOSFET spot it will definitively not work.
Especially if you are handling high current or voltage I would recommend using one from a reputable source for your MOSFET, I recently switched from mouser / digikey / aliexpress to mostly use http://www.arrow.com as you get free regular shipping, event if you order a couple of components (no affiliation to them whatsoever).
I have finally gotten back to this project and created a working sketch that communicates with my Vera controller. I have this set up as a 3 button on/off (6 switches on the board) and have that working successfully with Vera. I also have my Vera sending temperature data back to the OLED display. It alternates between the outside temp and room temp for my master bedroom where the switch is located. I have posted the Arduino sketch under source code here.
This should work with Domoticz, it's what I intend to use with it. I've received the boards from China and I'm currently working on a version 2 of this board. There are some errors in the design of version 1 that I need to get out. New version will be up shortly.