ct_clamp_sensor.cpp

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#include "ct_clamp_sensor.h"
 
#include "esphome/core/log.h"
#include <cinttypes>
#include <cmath>
 
namespace esphome::ct_clamp {
 
ESPHOME_LOG_TAG(TAG, "ct_clamp");
 
static constexpr uint32_t READ_TIMEOUT_ID = 0;
 
void CTClampSensor::dump_config() {
  LOG_SENSOR("", "CT Clamp Sensor", this);
  ESP_LOGCONFIG(TAG, "  Sample Duration: %.2fs", this->sample_duration_ / 1e3f);
  LOG_UPDATE_INTERVAL(this);
}
 
void CTClampSensor::update() {
  // Update only starts the sampling phase, in loop() the actual sampling is happening.
 
  // Request a high loop() execution interval during sampling phase.
  this->high_freq_.start();
 
  // Set timeout for ending sampling phase
  this->set_timeout(READ_TIMEOUT_ID, this->sample_duration_, [this]() {
    this->is_sampling_ = false;
    this->high_freq_.stop();
 
    if (this->num_samples_ == 0) {
      // Shouldn't happen, but let's not crash if it does.
      this->publish_state(NAN);
      return;
    }
 
    const float rms_ac_dc_squared = this->sample_squared_sum_ / this->num_samples_;
    const float rms_dc = this->sample_sum_ / this->num_samples_;
    const float rms_ac_squared = rms_ac_dc_squared - rms_dc * rms_dc;
    float rms_ac = 0;
    if (rms_ac_squared > 0)
      rms_ac = std::sqrt(rms_ac_squared);
    ESP_LOGD(TAG, "'%s' - Raw AC Value: %.3fA after %" PRIu32 " different samples (%" PRIu32 " SPS)",
             LOG_STR_ARG(this->get_log_name()), rms_ac, this->num_samples_,
             1000 * this->num_samples_ / this->sample_duration_);
    this->publish_state(rms_ac);
  });
 
  // Set sampling values
  this->last_value_ = 0.0;
  this->num_samples_ = 0;
  this->sample_sum_ = 0.0f;
  this->sample_squared_sum_ = 0.0f;
  this->is_sampling_ = true;
}
 
void CTClampSensor::loop() {
  if (!this->is_sampling_)
    return;
 
  // Perform a single sample
  float value = this->source_->sample();
  if (std::isnan(value))
    return;
 
  // Assuming a sine wave, avoid requesting values faster than the ADC can provide them
  if (this->last_value_ == value)
    return;
  this->last_value_ = value;
 
  this->num_samples_++;
  this->sample_sum_ += value;
  this->sample_squared_sum_ += value * value;
}
 
}  // namespace esphome::ct_clamp