Heating control with web backend

  • Hi!
    I have been working with simple heating control system. It will consist of

    • control nodes (Uno + RF24) with temperature measurement, 2 relay outputs for aux heating devices and possibility to add external temp sensors (all DS1820)
    • "serial" gateway (Mega2560 + RF24 + WiFi shield) to send measured values to web server and poll set value(s) from server (to control nodes). It also parses UTC time from HTTP response to update local time 😉
    • web server to collect and view data and keep set value(s)

    The system is very much in WIP and monitoring-only-testing phase, but so far it looks promising. Though sometimes it looks like there are "golden" build environment configurations - that just work - and flaky transmissions and long black periods 😄 Hopefully MyS 2.2 with mixed ACK handling will work better than 2.1 and 2.1.1.

    The server uses PHP, MySQL and Slim, with AngularJS and Google Charts on UI.

    Oh, the purpose 😉 I want to monitor our "summer" house. Heating is by water circulating central heating and electric (read: not cheap). To be able to use air-to-air heat pump efficiently, it would be necessary to turn down single radiators (heat pump is primary heat source, and if it keeps temps high enough, radiator should be shut, using one of the relay outputs) and possibly use electric heaters as backup/reserve/extra heat (when temps go really low, like when it's really cold or heat pump is on de-ice sequence, using the second relay output).

    For images, I may have to load them somewhere else and then link to them...

  • Though RF24 works quite well at my home, at remote location it's quite on/off. It can work for single measurement or one day or several days, and then have no data for a week. The gateway is running well, since it regularly contacts web server to get new set value(s) even on periods with no data.

    This led me to suspect problem with RF24, and to order 15 RFM69 radios + level converters. Boy, are they laborious to solder together and to proto shield (no more jumper wires 😉 ) on top of Uno! I could make and then test 2 pieces in one day, with magnifying glasses and 3rd hand. Damn 2mm raster on RFM69!

    If I can get RF24 working good enough, I'll stick with them. For good 🤔