Yes. Sorry for being MIA. Lots of projects in the works, and I was held up by delays in order processing and shipping on parts, apparently due to “Spring Festival/Golden Week”. I guess the week turned into months! This is another reason I would like to secure an inventory of parts, namely the electronic valves, to be able to offer for sale to others.
If anyone knows of a US supplier (not reseller) of motorized ball valves, I would be very interested.
I will post a full writeup of the current status of this project as soon as I can, but in the mean time, here is my advice based on our testing:
Definitely use a motorized ball valve for this application. All other valve types are failure prone or otherwise have unreliable results.
If hard wiring is not an option (ie use gpio on raspberry pi), you need to find a very reliable communication method to the valve, such as arduino or other dev board with wifi, ethernet, etc. Our testing has shown that the valve itself operates like a champ, but the bugs are always in communication between valve and device running openhab.
So far our solution uses a NodeMCU, replacing firmware with Arduino IDE based code. The temp and flow sensors are polled with the existing arduino code, and the valve control is essentially an openhab switch through the NodeMCU.
The charging circuit is surprisingly good using the micro-hydro generator, and allows for everything to be self contained and “wireless”. (Ie, no wires outside of waterproof enclosure.
Again,I will post detailed writeup and photos ASAP.
Sorry for the hiatus, and thanks for being patient with me.