I was looking for a reasonable open HVAC controller for my home. I wasn’t able to find anything more “off the shelf” than the PI Cubes solution. While it looks very competent, it lacks some of the convenience engineering of the OSPi, the most obvious being some sort of case and the requirement for a 24VDC power supply.
I was curious if any of the tinkerers here had noticed that the HVAC contol runs on 24VAC, which, by coincidence, is what our happy little sprinkler system is using.
Owner of a recent (Dec 2017) OpenSprinkler PI with a single “valve”, a Rainbird 220V pump start relay, zone control through a 4 output index valve (so analog!). Standard software works great using single program with 4 run times with 5 minutes delay between to allow the water pressure to drop, which steps the index valve to the next zone.
Samer and I have slowly started working on our next gadget, the OpenThermostat. Part of the design of OpenSprinkler 3.0 is to make the main (ESP8266) processor board separate from the solenoid driver board, so that the same processor board can be plugged into different driver board (such as an HVAC) board to make other controllers. The circuit is fairly easy to design but it’s the software that’s going to take a while to finish.