HLW8012 Power Sensor

The hlw8012 sensor platform allows you to use your HLW8012 voltage/current and power sensors (datasheet) sensors with ESPHome. This sensor is commonly found in Sonoff POWs. CSE7759 and BL0937 are similar to HLW8012 and work with this integration. Beware that CSE7759B is different and should be used with the CSE7766 integration.

Note

SAFETY HAZARD: Some devices such as Sonoff POWs/Shelly/etc, have the digital GND connected directly to mains voltage so the GPIOs become LIVE during normal operation. Our advice is to mark these boards to prevent any use of the dangerous digital pins.

This sensor has two data outputs which both encode values using the frequency of a modulated signal: CF and CF1. CF’s frequency is proportional to the (active) power measured and CF1 is proportional to the current/voltage. Using the SEL pin, one can choose between which mode to use.

ESPHome will continuously cycle the state of the SEL pin to measure current and voltage, though both cannot be measured at the same exact points in time.

# Example configuration entry
sensor:
  - platform: hlw8012
    sel_pin: 5
    cf_pin: 14
    cf1_pin: 13
    current:
      name: "HLW8012 Current"
    voltage:
      name: "HLW8012 Voltage"
    power:
      name: "HLW8012 Power"
    energy:
      name: "HLW8012 Energy"
    update_interval: 60s

Note

The configuration above should work for Sonoff POWs (R1).

Configuration variables:

  • sel_pin (Required, Pin Schema): The pin SEL is connected to.

  • cf_pin (Required, Pin): The pin CF is connected to.

  • cf1_pin (Required, Pin): The pin CF1 is connected to.

  • current (Optional): Use the current value of the sensor in amperes. All options from Sensor.

  • power (Optional): Use the (active) power value of the sensor in watts. All options from Sensor.

  • voltage (Optional): Use the voltage value of the sensor in V (RMS). All options from Sensor.

  • energy (Optional): Use the total energy value of the sensor in Wh. All options from Sensor.

  • update_interval (Optional, Time): The interval to check the sensor. Defaults to 60s.

Advanced Options:

  • current_resistor (Optional, float): The value of the shunt resistor for current measurement. Defaults to the Sonoff POW’s value 0.001 ohm.

  • voltage_divider (Optional, float): The value of the voltage divider on the board as (R_upstream + R_downstream) / R_downstream. Defaults to the Sonoff POW’s value 2351.

  • model (Optional, string): The sensor model on the board, to set internal constant factors to convert pulses to measurements. Possible values are HLW8012, CSE7759, BL0937. Defaults to HLW8012. CSE7759 uses same constants and it also works with default. Must be set for BL0937 to be able to calibrate all three measurements at the same time.

  • change_mode_every (Optional, int): After how many updates to cycle between the current/voltage measurement mode. Note that the first value after switching is discarded because it is often inaccurate. Defaults to 8.

  • initial_mode (Optional, string): The initial measurement mode. Defaults to VOLTAGE. Possible initial measurement modes are VOLTAGE or CURRENT.

Permanent SEL Pin

Some devices have the SEL pin permanently pulled high or low. If this is the case, you can configure the initial measurement mode to match whichever mode the device uses, and disable mode switching.

# Example configuration entry for device with fixed measurement mode
sensor:
  - platform: hlw8012
    sel_pin: 5
    cf_pin: 14
    cf1_pin: 13
    current:
      name: "HLW8012 Current"
    voltage:
      name: "HLW8012 Voltage"
    power:
      name: "HLW8012 Power"
    update_interval: 60s
    initial_mode: CURRENT
    change_mode_every: 4294967295

SEL Pin Inversion

If using model BL0937 the function of the SEL pin is inverted compared to default. When SEL=0 current is measured, when SEL=1 voltage is measured. To accommodate this change use the following configuration:

# Example configuration entry for device BL0937 using inverted SEL pin functionality
sensor:
  - platform: hlw8012
    model: BL0937
    sel_pin:
      number: 12
      inverted: true
    cf_pin: 4
    cf1_pin: 5
    current:
      name: "BL0937 Current"
    voltage:
      name: "BL0937 Voltage"
    power:
      name: "BL0937 Power"
    update_interval: 60s

See Also