This story begin in the 2014 when I was finishing building my house. Me and my girlfriend opted for a pellet idro-stove for the heating system… with radiators spread around the house. I said to my plumber to configure that and install two solenoid valve in the basement, one for floor. The thermostat will be my work.

In my first idea, a single raspberry in the basement will be monitor the temperature at floor 0 and floor 1 with two DS18B20 sensors and will control 3 relay. One relay for solenoid valve, and the third for switch on/off the stove.

This idea was good… But it’s reliable? Let’s do like this… I will add a UPS to raspberry. And I will add a manual system for switch on/off solenoid valve in case of emergency.

I named this project SILVANO. And in the future I will use this name for my generic domotic home, hardware and software. I will referred to Silvano like if he is a real person (his photo is below). I like it. Go Silvano go!

This is a simple schema that represent my raspberry, sensors and relays, my two solenoid valves, the contact for the stove, and the manual box for emergency switch on and off.

This is obviously a generic one-wire schema. Now I can design every single part with more details. First of all, the stove, a Laminox Carlotta 24kW, have a external thermostat with 2 plug. When I connect with one wire this two contacts, the stove fire on. When disconnect, the stove fire off (in another post I will spoke with major details of this stove)

It’s meaning that I will connect this two wire with the NC contact of third relay. For the solenoid valves (Comparato Microdiam two ways), here is the schema (in italian).

For the DS18B20 sensor, I follow the instruction found on internet and I added a pull-up resistor. In reality I use this single resistor for 3 sensors and its  works perfectly.

Ok, the hardware project is done. In the next post we configure the raspberry for the first time and write some code in php and c++.