related, older thermostats are just a pair of contacts that open/close based on tempThe clever thing would be to examine the room controllers to see if they would work at low voltage, or add a redundant set of controllers that did.
if the thermostat is old enough, you can just run 3.3v thru its contacts, and entirely disconnect it from the 240vac, then all risk is gone
but for my own heating setup, i just deleted the thermostats entirely
an array of ds18b20's read the temp in each room
an atmega168 reads the temps (i designed this a decade ago, before pico's)
the atmega then has set points, and wiggles gpio when temps go past certain set-points
and the uart exports data for graphing and allows control of the setpoints
if i was to redo this today, i would probably use a pico-w and mqtt
Statistics: Posted by cleverca22 — Wed Nov 20, 2024 10:40 am