It is time to take a spin the analog input capability of my Homemade Environment Sensor.
Here is the sensor that I am using.
I learn about this sensor from here.
I will not bore you guys with the detail. What I do differently is a much simpler interpretation of the data. The link above concentrate on power metering (or measuring power consumption). On the other hand, I am looking whether AC current exist. I read the voltage value as well. I only care whether the voltage value change. This should work with most AC appliance.
Here is a short demo. Just a note, in the demo, you will see a couple different implementation. I convert a bad sound detector sensor to detect the AC signal. The detector has comparator that can give me binary output to determine when the current oscillate.