Before I start digging up the protocol and will be staring at bits & bytes for quite some time, I thought it would be good to first give a short impression of the ELV MAX! products that arrived yesterday: a MAX! Cube LAN Gateway and a Radiator Thermostat.
The Radiator Thermostat feels good – it’s made of plastic, but it doesn’t make it feel light or cheap. And it’s big, but not too big. The big LCD is a smart choice IMO, cause with radiator valves just 20 cm above the floor you can still read the temperature set-point and the various icons very well – no need to get on your knees. I’m satisfied with the looks so far; the only thing that worries me a bit is the M30 nut which is also made of plastic. I would have preferred a metal one, just like the one on the Honeywell HR-80. But hey, look at the price difference between those two.. well, I guess we’ll know how this plastic nut performs soon enough 😉 The big knob with which the temperature setpoint can be altered works and feels good as well. No complaints so far.
The Cube is ehm, well, a cube. White, with a RJ-45 connector for LAN and a USB connector for power. The power adapter has a USB connector too, so you don’t need a PC nearby; working with the Cube is completely LAN based. 3 green LEDs on the top of the Cube show the status for power, Internet and Battery. Power consumption of the Cube: 0.9 W. That’s acceptable; I’ve seen worse!
After unpacking everything, I started with inserting the batteries into the Radiator Thermostat with the Thermostat still on my desk. After the batteries were inserted, it started doing its ‘adapter run’ so the thermostat can find out how/where the pin of the radiator valve is positioned and how much this pin can be moved. I immediately got an F2 error, which I already anticipated since the Thermostat didn’t get any resistance from a real radiator valve. So I mounted it to a radiator valve, started the ‘adapter run’ again and unscrewed the Thermostat from the radiator after it finished this run. Back on my desk with this Radiator Thermostat, cause I don’t like to walk back and forth between desk and the nearest radiator!
Next I started up the Cube, downloaded a MAX! App from the ELV site, installed, started the App and saw the Cube being auto-discovered. Default mode for the Cube’s LAN connection is DHCP, BTW. The App told me I needed a firmware upgrade before I could proceed, so I let the app take care of that. I teached-in the Radiator Thermostat and looked around in the MAX App; pushed some buttons, changed some settings, turned the Thermostat knob manually, adjusted a schedule etcetera; after 15 minutes or so I had seen enough; this app is not going to be used. Not because it doesn’t work good, has flaws or whatever reason, but it’s not integrated!
Depending on how well the ELV MAX! protocol can be dissected into all the details, I will maybe use it to teach-in new Thermostats; we’ll see. But that should be all, the rest of it all should be doable from my own system.
I’ve already started with decoding the incoming ‘H:’,’M:’ and ‘C:’ messages that are received when a TCP connection is opened to port 80 of the MAX! Cube. Those responses contain very interesting configuration data. More on that later… 🙂
Update: I posted some protocol information on the Domoticaforum. Enjoy!