CT clamp not calibrating


I’ve setup esphome on a WeMos D1 mini with a CT clamp on A0 but the calibration doesn’t seem to be working. I’ve pretty much copied and pasted the code from the example. My readings currently bounce between 0 and 0.12 and don’t change if I remove the calibration.

  - platform: ct_clamp
    sensor: adc_sensor
    name: "Measured Current"
    update_interval: 60s
      - calibrate_linear:
          - 0 -> 0
          - 0.12 -> 18


That could be noise. Does your CT have a sense resistor to generate a voltage that the ADC can read?

If not you need to supply one that is calculated to generate near the maximum ADC in voltage (1V or 3.3V depending on the board) when the maximum current is flowing through the conductor the CT is clamped around.

Sorry, I possibly phrased the question badly.

From what I can see, the noise is quite low as I chose the resistors carefully. Readings in-app are 0 most of the time and increase to 0.12 when the load is on but I would expect to see values between 0 (load off) and 18 (load on) after the calibration.

If you chose the resistor carefully you should see a lot more than 0.12V at full load. Or is this not at full load?