ATM90E32 Power Sensor

The atm90e32 sensor platform allows you to use your ATM90E32 voltage/current and power sensors (datasheet) with ESPHome. This sensor is commonly found in CircuitSetup 2 and 6 channel energy meters and the Gelidus Research 2 channel power meter.

Communication with the device is done via an SPI bus, so you need to have an spi: entry in your configuration with both mosi_pin and miso_pin set.

The ATM90E32 IC can measure up to three AC voltages although typically only one voltage measurement would be used for the mains electricity phase of a household. Three current measurements are read via CT clamps.

The CircuitSetup Split Single Phase Energy Meter can read 2 current channels and 1 (expandable to 2) voltage channel.

../../_images/atm90e32-cs-2chan-full.jpg

CircuitSetup Split Single Phase Real Time Whole House Energy Meter.

The CircuitSetup 6-Channel Energy Monitor can read 6 current channels and 2 voltage channels at a time, this board has two ATM90E32 ICs and requires two sensors to be configured in ESPHome.

../../_images/atm90e32-cs-6chan-full.jpg

CircuitSetup Expandable 6 Channel ESP32 Energy Meter Main Board.

Configuration variables:

  • cs_pin (Required, Pin Schema): The pin CS is connected to. For the 6 channel meter main board, this will always be 5 and 4. For the add-on boards a jumper can be selected for each CS pin, but default to 0 and 16.

  • line_frequency (Required, string): The AC line frequency of the supply voltage. One of 50Hz, 60Hz.

  • phase_a (Optional): The configuration options for the 1st phase.

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

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

    • power (Optional): Use the power value on this phase in watts. All options from Sensor.

    • reactive_power (Optional): Use the reactive power value on this phase. All options from Sensor.

    • power_factor (Optional): Use the power factor value on this phase. All options from Sensor.

    • phase_angle (Optional): Use the phase angle value on this phase in degrees. All options from Sensor.

    • peak_current (Optional): Use the peak current value on this phase in amperes. All options from Sensor.

    • harmonic_power (Optional): Use the harmonic power value on this phase. All options from Sensor.

    • gain_voltage (Optional, int): Voltage gain to scale the low voltage AC power pack to household mains feed. Defaults to 7305.

    • gain_ct (Optional, int): CT clamp calibration for this phase. Defaults to 27961.

    • forward_active_energy (Optional): Use the forward active energy value on this phase in watt-hours. All options from Sensor.

    • reverse_active_energy (Optional): Use the reverse active energy value on this phase in watt-hours. All options from Sensor.

  • phase_b (Optional): The configuration options for the 2nd phase. Same options as 1st phase.

  • phase_c (Optional): The configuration options for the 3rd phase. Same options as 1st phase.

  • frequency (Optional): Use the frequency value calculated by the meter. All options from Sensor.

  • peak_current_signed (Optional, boolean): Control the peak current output as signed or absolute. Defaults to false.

  • chip_temperature (Optional): Use the chip temperature value. All options from Sensor.

  • gain_pga (Optional, string): The gain for the CT clamp, 2X for 100A, 4X for 100A - 200A. One of 1X, 2X, 4X. Defaults to 2X which is suitable for the popular SCT-013-000 clamp.

  • current_phases (Optional): The number of phases the meter has, 2 or, 3 The 6 Channel Expandable Energy Meter should be set to 3, and the Split Single Phase meter should be set to 2. Defaults to 3.

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

  • spi_id (Optional, ID): Manually specify the ID of the SPI Component if you want to use multiple SPI buses.

  • enable_offset_calibration (Optional, boolean): If true it enables fine grained offset noise 0 level calibration for voltage and current sensors. Buttons are required to operate the calibration feature. With multiple atm90e32 sensors each one is enabled individually and it’s buttons are mapped using an id value pair. e.g. id: chip1 when more than one is defined. Offset calibration should only be used when DC supply noise causes non 0 current or voltage readings. Calibration can only be performed when all voltage and current inputs are at a 0 value.

Button

button:
  - platform: atm90e32
    id: chip1
    run_offset_calibration:
      name: "Chip1 - Run Offset Calibration"
    clear_offset_calibration:
      name: "Chip1 - Clear Offset Calibration"

Configuration variables:

  • id (Optional, ID): The ID of the atm90e32 defined above. Required if there are multiple atm90e32 configured.

  • run_offset_calibration (Optional): A button to run the offset calibration. All options from Button.

  • clear_offset_calibration (Optional): A button to clear the offset calibration. All options from Button.

Calibration

This sensor needs calibration to show correct values. The default gain configuration is set to use the SCT-013-000 current transformers, and the Jameco Reliapro 9v AC transformer. A load which uses a known amount of current can be used to calibrate. For for a more accurate calibration use a Kill-A-Watt meter or similar, mains voltages can fluctuate depending on grid load.

Voltage

Use the expected mains voltage for your region 110V/230V or plug in the Kill-A-Watt and select voltage. See what value the ATM90E32 sensor reports for voltage. To adjust the sensor use the calculation:

New gain_voltage = (your voltage reading / ESPHome voltage reading) * existing gain_voltage value

Update gain_voltage for all phases in your ESPHome yaml, recompile and upload. Repeat as necessary.

Here are common voltage calibrations for the Split Single Energy Meter:
For meter <= v1.3:
  • 42080 - 9v AC Transformer - Jameco 112336

  • 32428 - 12v AC Transformer - Jameco 167151

For meter > v1.4:
  • 37106 - 9v AC Transformer - Jameco 157041

  • 38302 - 9v AC Transformer - Jameco 112336

  • 29462 - 12v AC Transformer - Jameco 167151

For Meters >= v1.4 rev.3
  • 3920 - 9v AC Transformer - Jameco 157041

Here are common voltage calibrations for the Expandable 6 Channel Energy Meter:
For meter <= v1.2:
  • 42080 - 9v AC Transformer - Jameco 112336

  • 32428 - 12v AC Transformer - Jameco 167151

For meter > v1.3:
  • 7305 - 9v AC Transformer - Jameco 157041

Current

Switch on the current load and see what value the ATM90E32 sensor reports for current on the selected phase. Using the known or measured current adjust the sensor using calculation:

New gain_ct = (your current reading / ESPHome current reading) * existing gain_ct value

Update gain_ct for the phase in your ESPHome yaml, recompile and upload. Repeat as necessary.

It is possible that the two identical CT current sensors will have different gain_ct numbers due to variances in manufacturing, although it will be small. The current calibration can be done once and used on all sensors or repeated for each one.

Here are common current calibration values for the Split Single Phase Energy Meter when gain_pga is set to 4X:
  • 200A/100mA SCT-024: 12597

Here are common current calibration values for the Split Single Phase Energy Meter when gain_pga is set to 2X:
  • 20A/25mA SCT-006: 10170

  • 100A/50mA SCT-013-000: 25498

  • 120A/40mA SCT-016: 39473

  • Magnalab 100A: 46539

Here are common current calibrations for the Expandable 6 Channel Energy Meter when gain_pga is set to 1X:
  • 20A/25mA SCT-006: 11131

  • 30A/1V SCT-013-030: 8650

  • 50A/1V SCT-013-050: 15420

  • 80A/26.6mA SCT-010: 41996 (note this will saturate at 2^16/10^3 amps)

  • 100A/50ma SCT-013-000: 27961

  • 120A/40mA: SCT-016: 41880

Active Energy

The ATM90E32 chip has a high-precision built-in ability to count the amount of consumed energy on a per-phase basis. For each phase both the Forward and Reverse active energy is counted in watt-hours. Forward Active Energy is used to count consumed energy, whereas Reverse Active Energy is used to count exported energy (e.g. with solar PV installations). The counters are reset every time a given active energy value is read from the ATM90E32 chip.

Current implementation targets users who retrieve the energy values with a regular interval and store them in a time-series-database, e.g. InfluxDB.

Example:

sensor:
#IC1 Main
  - platform: atm90e32
    cs_pin: GPIOXX
    phase_a:
      forward_active_energy:
        name: ${disp_name} ct1 FAWattHours
        id: ct1FAWattHours
        state_topic: ${disp_name}/ct1/forward_active_energy
      reverse_active_energy:
        name: ${disp_name} ct1 RAWattHours
        id: ct1RAWattHours
        state_topic: ${disp_name}/ct1/reverse_active_energy

If the power, power_factor, reactive_power, forward_active_energy, or reverse_active_energy configuration variables are used, care must be taken to ensure that the line ATM90E32’s voltage is from is the same phase as the current transformer is installed on. This is significant in split-phase or multi phase installations. On a house with 240 split-phase wiring (very common in the US), one simple test is to reverse the orientation of the current transformer on a line. If the power factor doesn’t change sign, it is likely that the voltage fed to the ATM90E32 is from the other phase.

The CircuitSetup Expandable 6 channel board can easily handle this situation by cutting the jumpers JP12/13 to allow a separate VA2 to be input on the J3 pads. Make sure that current taps connected to CT 1-3 are on the phase from which VA is fed (the barrel jack) and the taps connected to CT3-6 are on the phase from which VA2 is fed. See the CicuitSetup repo for more details on this.

If a multi board stack is being used, remember to cut JP12/13 on all boards and to feed VA2 to each board. VA is fed to all boards through the stacking headers. Another detail is that each voltage transformer needs to have the same polarity; getting this backwards will be just like having it on the wrong phase.

Note that the current measurement is the RMS value so is always positive. They only way to determine direction is to look at the power factor. If there are only largely resistive loads and no power sources, (PF almost 1), it is simpler to just create a template sensor that computes power from Irms*Vrms and ignore all these details. On the other hand, one might be surprised how reactive some loads are and the CirciuitSetup designs are able to handle these situations well.

Additional Examples

# Example configuration entry for split single phase meter
spi:
  clk_pin: GPIOXX
  miso_pin: GPIOXX
  mosi_pin: GPIOXX

sensor:
  - platform: atm90e32
    cs_pin: GPIOXX
    phase_a:
      voltage:
        name: "EMON Line Voltage A"
      current:
        name: "EMON CT1 Current"
      power:
        name: "EMON Active Power CT1"
      reactive_power:
        name: "EMON Reactive Power CT1"
      power_factor:
        name: "EMON Power Factor CT1"
      gain_voltage: 3920
      gain_ct: 39473
    phase_c:
      current:
        name: "EMON CT2 Current"
      power:
        name: "EMON Active Power CT2"
      reactive_power:
        name: "EMON Reactive Power CT2"
      power_factor:
        name: "EMON Power Factor CT2"
      gain_voltage: 3920
      gain_ct: 39473
    frequency:
      name: "EMON Line Frequency"
    chip_temperature:
      name: "EMON Chip Temperature"
    line_frequency: 50Hz
    current_phases: 2
    gain_pga: 2X
    update_interval: 60s
# Example CircuitSetup 6-channel entry
spi:
  clk_pin: 18
  miso_pin: 19
  mosi_pin: 23
sensor:
  - platform: atm90e32
    cs_pin: 5
    id: chip1 #Optional
    phase_a:
      voltage:
        name: "EMON Line Voltage A"
      current:
        name: "EMON CT1 Current"
      power:
        name: "EMON Active Power CT1"
      gain_voltage: 7305
      gain_ct: 12577
    phase_b:
      current:
        name: "EMON CT2 Current"
      power:
        name: "EMON Active Power CT2"
      gain_voltage: 7305
      gain_ct: 12577
    phase_c:
      current:
        name: "EMON CT3 Current"
      power:
        name: "EMON Active Power CT3"
      gain_voltage: 7305
      gain_ct: 12577
    frequency:
      name: "EMON Line Frequency"
    line_frequency: 50Hz
    current_phases: 3
    gain_pga: 1X
    update_interval: 60s
    enable_offset_calibration: True
  - platform: atm90e32
    cs_pin: 4
    id: chip2 #Optional
    phase_a:
      current:
        name: "EMON CT4 Current"
      power:
        name: "EMON Active Power CT4"
      gain_voltage: 7305
      gain_ct: 12577
    phase_b:
      current:
        name: "EMON CT5 Current"
      power:
        name: "EMON Active Power CT5"
      gain_voltage: 7305
      gain_ct: 12577
    phase_c:
      current:
        name: "EMON CT6 Current"
      power:
        name: "EMON Active Power CT6"
      gain_voltage: 7305
      gain_ct: 12577
    line_frequency: 50Hz
    current_phases: 3
    gain_pga: 1X
    update_interval: 60s

button:
  - platform: atm90e32
    id: chip1
    run_offset_calibration:
      name: "Chip1 - Run Offset Calibration"
    clear_offset_calibration:
      name: "Chip1 - Clear Offset Calibration"
# Example CircuitSetup 6-channel without jumpers jp9-jp11 joined or < meter v1.4
# power is calculated in a template

substitutions:
  disp_name: 6C
  update_time: 10s
  current_cal: '27961'

spi:
  clk_pin: 18
  miso_pin: 19
  mosi_pin: 23
sensor:
  - platform: atm90e32
    cs_pin: 5
    phase_a:
      voltage:
        name: ${disp_name} Volts A
        id: ic1Volts
        accuracy_decimals: 1
      current:
        name: ${disp_name} CT1 Amps
        id: ct1Amps
      gain_voltage: 7305
      gain_ct: ${current_cal}
    phase_b:
      current:
        name: ${disp_name} CT2 Amps
        id: ct2Amps
      gain_ct: ${current_cal}
    phase_c:
      current:
        name: ${disp_name} CT3 Amps
        id: ct3Amps
      gain_ct: ${current_cal}
    frequency:
      name: ${disp_name} Freq A
    line_frequency: 60Hz
    current_phases: 3
    gain_pga: 1X
    update_interval: ${update_time}
  - platform: atm90e32
    cs_pin: 4
    phase_a:
      voltage:
        name: ${disp_name} Volts B
        id: ic2Volts
        accuracy_decimals: 1
      current:
        name: ${disp_name} CT4 Amps
        id: ct4Amps
      gain_voltage: 7305
      gain_ct: ${current_cal}
    phase_b:
      current:
        name: ${disp_name} CT5 Amps
        id: ct5Amps
      gain_ct: ${current_cal}
    phase_c:
      current:
        name: ${disp_name} CT6 Amps
        id: ct6Amps
      gain_ct: ${current_cal}
    frequency:
      name: ${disp_name} Freq B
    line_frequency: 60Hz
    current_phases: 3
    gain_pga: 1X
    update_interval: ${update_time}

#Watts per channel
  - platform: template
    name: ${disp_name} CT1 Watts
    id: ct1Watts
    lambda: return id(ct1Amps).state * id(ic1Volts).state;
    accuracy_decimals: 0
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
  - platform: template
    name: ${disp_name} CT2 Watts
    id: ct2Watts
    lambda: return id(ct2Amps).state * id(ic1Volts).state;
    accuracy_decimals: 0
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
  - platform: template
    name: ${disp_name} CT3 Watts
    id: ct3Watts
    lambda: return id(ct3Amps).state * id(ic1Volts).state;
    accuracy_decimals: 0
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
  - platform: template
    name: ${disp_name} CT4 Watts
    id: ct4Watts
    lambda: return id(ct4Amps).state * id(ic2Volts).state;
    accuracy_decimals: 0
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
  - platform: template
    name: ${disp_name} CT5 Watts
    id: ct5Watts
    lambda: return id(ct5Amps).state * id(ic2Volts).state;
    accuracy_decimals: 0
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
  - platform: template
    name: ${disp_name} CT6 Watts
    id: ct6Watts
    lambda: return id(ct6Amps).state * id(ic2Volts).state;
    accuracy_decimals: 0
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
#Total Amps
  - platform: template
    name: ${disp_name} Total Amps
    id: totalAmps
    lambda: return id(ct1Amps).state + id(ct2Amps).state + id(ct3Amps).state + id(ct4Amps).state + id(ct5Amps).state + id(ct6Amps).state ;
    accuracy_decimals: 2
    unit_of_measurement: A
    icon: "mdi:flash"
    update_interval: ${update_time}
#Total Watts
  - platform: template
    name: ${disp_name} Total Watts
    id: totalWatts
    lambda: return id(totalAmps).state * id(ic1Volts).state;
    accuracy_decimals: 1
    unit_of_measurement: W
    icon: "mdi:flash-circle"
    update_interval: ${update_time}
#kWh
  - platform: total_daily_energy
    name: ${disp_name} Total kWh
    power_id: totalWatts
    filters:
      - multiply: 0.001
    unit_of_measurement: kWh

Harmonic Power

Harmonic power in AC systems refers to deviations from the ideal sinusoidal waveform, caused by multiples of the fundamental frequency. It results from non-linear loads and can lead to issues like voltage distortion, equipment overheating, and miss operation of protective devices. The ATM90E32 can output advanced harmonic power measurements providing important analysis data for monitoring power anomalies on the bus.

Harmonic Power Example:

sensor:
  - platform: atm90e32
    phase_a:
      harmonic_power:
        name: ${disp_name} CT1 Harmonic Power

Phase Angle

Phase angle in AC systems represents the angular displacement of a sinusoidal waveform from a reference point. It’s a measure of timing difference between voltage and current. Phase angle is crucial for power factor assessment and efficient power transfer. This advanced measurement function is available with an ATM90E32.

Phase Angle Example:

sensor:
  - platform: atm90e32
    phase_a:
      phase_angle:
        name: ${disp_name} L1 Phase Angle

Peak Current

Peak current in AC systems refers to the maximum value of the alternating current waveform. It signifies the highest magnitude reached during each cycle of the sinusoidal waveform. Peak current is relevant for sizing components and assessing the capacity of electrical equipment in the system. This advanced measurement is available from the ATM90E32. Peak current can be displayed in signed or unsigned format using a boolean parameter which spans all phases. The default is false which is unsigned.

Peak Current Example:

sensor:
  - platform: atm90e32
    phase_a:
      peak_current:
        name: ${disp_name} CT1 Peak Current
  peak_current_signed: True

See Also