Looking to connect a wifi relay to my gate motor and integrate into home assist, the motor is solar powered and I would like to monitor the input voltage as to check if the relay is drawing to much from the battery’s overnight.
I notice devices such as the Shelly pm 1 support power monitoring, but they all seem to only monitor the load not the input.
Is there a relay that can display the input voltage once integrated into home assist?
Ok - for 24V DC you can simply build a voltage divider and measure the voltage using the ESP32 ADC. This assumes you are ok with soldering components etc.
Assume a max source voltage of 28V, R1 could be a 300KOhm resistor , R2 a 40KOhm resistor which means that the output voltage of the divider is 0-3.3V, which an ESP32 can read with an ADC, using ESPHome.
No problem. If you build something don’t forget to test with a multimeter that you get voltages in the expected range. This will save blowing up your ESP.