kw123 wrote:bme280 or bmp 280 or bme680 sensor have temp/ pressure +(280 :humidity, 680:air quality) , cost ~ $2..$20 + either ESP or raspberry pi
They should be sensitive enough
Karl
I actually have a pair of the temperature-pressure ones as well as a Pi0W sitting by my server to build an AC monitor like he is talking about; I just haven't had time to setup the pi, but once that's done, it will be just a simple create devices and variables and write some triggers... However, I figured to put them on either side of the coil... I plan on calculating the delta )P between when the AC turned on and went off to get the dp across the filter and monitor the delta T and humidity across the coil to track how well the compressor was performing as the outside temperature climbs. My only irritation is that all the One-wire devices only give you a choice of two IDs FE and FF; The Pi could support a whole stablefull of them if more than on e GPIO could talk one wire, but as it is two at a time is all I can access.