A sensor/detector for connecting an alarm system to HA

[pkscout (Kyle Johnson)]

If you’re up for a little soldering, it looks like you could build one using an ESP32 device, a DC sensor, and ESPHome.

I found this thread:

Measuring 12v on ESP32 or ESP8266

I’m looking to make a device that will monitor the voltage of a generator battery that should be around 12v, maybe as much as 14v. I have a plan on what to do, but would like confirmation before I attempt this. May start off with a esp8266 but may switch to a esp32 to be able to hook up more than 1 monitored point on the generator. I would have 12v or so coming from the battery to a DC0-25v that will divide the voltage by 5. The esp32 or esp8266 can handle input voltages up to 3.3v. So, as long…

That mentions this sensor:

INA219 DC Current Sensor

Attach that to the I2C bus of an ESP32, and you should be able build a YAML file for ESPHome that will get the device to report the state to Home Assistant.

I’m doing something similar with a different sensor to detect an AC current.