ATM90E32 Arduino Library

This library powers the CircuitSetup Split Single Phase Energy Meter and the 6 Channel Expandable Energy Meter.

Highlights

• Keeps the legacy begin(...) API for existing sketches.
• Adds ATM90E32::Config and per-phase configuration for ESPHome-style setup.
• Supports 50 Hz / 60 Hz setup, 2-phase / 3-phase mode, harmonic power, peak current, and signed phase angles.
• Adds cumulative per-phase forward/reverse active energy in Wh.
• Adds phase and frequency status helpers.
• Adds gain, voltage/current offset, and power offset calibration flows.
• Saves calibration data on ESP32 with Preferences; other Arduino targets keep calibration runtime-only.

Legacy Setup

Existing sketches can keep using the original begin(...) signature:

#include <ATM90E32.h>

ATM90E32 energyMeter;

void setup() {
  energyMeter.begin(CS_pin, lineFreq, PGAGain, VoltageGain, CurrentGainCT1, CurrentGainCT2, CurrentGainCT3);
}

Config-Driven Setup

The new API mirrors ESPHome's configuration model more closely:

#include <ATM90E32.h>

ATM90E32 energyMeter;

void setup() {
  ATM90E32::Config config;
  config.csPin = 5;
  config.lineFrequency = ATM90E32::LINE_FREQUENCY_60HZ;
  config.currentPhases = ATM90E32::CURRENT_PHASES_2;
  config.pgaGain = ATM90E32::PGA_GAIN_1X;
  config.enableGainCalibration = true;
  config.enableOffsetCalibration = true;

  config.phase[ATM90E32::PHASE_A].voltageGain = 7305;
  config.phase[ATM90E32::PHASE_A].currentGain = 27961;
  config.phase[ATM90E32::PHASE_A].referenceVoltage = 120.0f;
  config.phase[ATM90E32::PHASE_A].referenceCurrent = 5.0f;

  config.phase[ATM90E32::PHASE_B].voltageGain = 7305;
  config.phase[ATM90E32::PHASE_B].currentGain = 27961;

  config.phase[ATM90E32::PHASE_C].voltageGain = 7305;
  config.phase[ATM90E32::PHASE_C].currentGain = 27961;

  if (!energyMeter.begin(config)) {
    Serial.println("ATM90E32 init failed");
  }
}

Common Measurements

void loop() {
  double voltageA = energyMeter.GetLineVoltageA();
  double currentA = energyMeter.GetLineCurrentA();
  double powerA = energyMeter.GetActivePowerA();
  double totalPower = energyMeter.GetTotalActivePower();
  double harmonicPowerA = energyMeter.GetHarmonicActivePowerA();
  double peakCurrentA = energyMeter.GetPeakCurrentA();
  double signedAngleA = energyMeter.GetSignedPhaseAngleA();
}

Other available getters include:

• GetReactivePowerA/B/C() and GetTotalReactivePower()
• GetApparentPowerA/B/C() and GetTotalApparentPower()
• GetPowerFactorA/B/C() and GetTotalPowerFactor()
• GetPhaseA/B/C() for raw phase angle and GetSignedPhaseAngleA/B/C() for [-180, 180]
• GetTotalActiveFundPower() and GetTotalActiveHarPower()
• GetFrequency()
• GetTemperature()

Energy Counters

Total energy getters keep the legacy behavior and return kWh from the ATM90E32 total registers:

• GetImportEnergy()
• GetImportReactiveEnergy()
• GetImportApparentEnergy()
• GetExportEnergy()
• GetExportReactiveEnergy()

Per-phase forward/reverse active energy getters are cumulative Wh counters built on the chip's read-and-clear phase registers:

• GetForwardActiveEnergyA/B/C()
• GetReverseActiveEnergyA/B/C()
• GetImportEnergyA/B/C()
• GetExportEnergyA/B/C()

You can clear the cumulative per-phase counters in software with:

• ResetEnergyAccumulators()

Status Helpers

Raw status registers are still available:

• GetSysStatus0()
• GetSysStatus1()
• GetMeterStatus0()
• GetMeterStatus1()

The new decoded helpers are:

• GetPhaseStatus(ATM90E32::PHASE_A/B/C)
• GetPhaseStatusText(ATM90E32::PHASE_A/B/C)
• GetFrequencyStatus()
• GetFrequencyStatusText()

Calibration

Reference values can be updated in code:

energyMeter.SetReferenceVoltage(ATM90E32::PHASE_A, 120.0f);
energyMeter.SetReferenceCurrent(ATM90E32::PHASE_A, 5.0f);

Calibration helpers:

• RunGainCalibration()
• RunOffsetCalibration()
• RunPowerOffsetCalibration()
• ClearGainCalibration()
• ClearOffsetCalibration()
• ClearPowerOffsetCalibration()

Legacy helpers are still present:

• CalculateVIOffset(...)
• CalculatePowerOffset(...)
• CalibrateVI(...)

On ESP32, the run/clear calibration methods save and restore calibration values with Preferences, keyed by the chip-select pin. On non-ESP32 Arduino targets, the same methods apply calibration values to the ATM90E32 for the current boot only.

Raw Register Access

Any ATM90E32 register defined in ATM90E32.h can still be read directly:

double raw = energyMeter.GetValueRegister(UrmsA);