ultrasonic_sensor.cpp

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#include "ultrasonic_sensor.h"
#include "esphome/core/log.h"
#include "esphome/core/hal.h"

namespace esphome {
namespace ultrasonic {

static const char *const TAG = "ultrasonic.sensor";

void UltrasonicSensorComponent::setup() {
  ESP_LOGCONFIG(TAG, "Setting up Ultrasonic Sensor...");
  this->trigger_pin_->setup();
  this->trigger_pin_->digital_write(false);
  this->echo_pin_->setup();
  // isr is faster to access
  echo_isr_ = echo_pin_->to_isr();
}
void UltrasonicSensorComponent::update() {
  this->trigger_pin_->digital_write(true);
  delayMicroseconds(this->pulse_time_us_);
  this->trigger_pin_->digital_write(false);

  const uint32_t start = micros();
  while (micros() - start < timeout_us_ && echo_isr_.digital_read())
    ;
  while (micros() - start < timeout_us_ && !echo_isr_.digital_read())
    ;
  const uint32_t pulse_start = micros();
  while (micros() - start < timeout_us_ && echo_isr_.digital_read())
    ;
  const uint32_t pulse_end = micros();

  ESP_LOGV(TAG, "Echo took %" PRIu32 "µs", pulse_end - pulse_start);

  if (pulse_end - start >= timeout_us_) {
    ESP_LOGD(TAG, "'%s' - Distance measurement timed out!", this->name_.c_str());
    this->publish_state(NAN);
  } else {
    float result = UltrasonicSensorComponent::us_to_m(pulse_end - pulse_start);
    ESP_LOGD(TAG, "'%s' - Got distance: %.3f m", this->name_.c_str(), result);
    this->publish_state(result);
  }
}
void UltrasonicSensorComponent::dump_config() {
  LOG_SENSOR("", "Ultrasonic Sensor", this);
  LOG_PIN("  Echo Pin: ", this->echo_pin_);
  LOG_PIN("  Trigger Pin: ", this->trigger_pin_);
  ESP_LOGCONFIG(TAG, "  Pulse time: %" PRIu32 " µs", this->pulse_time_us_);
  ESP_LOGCONFIG(TAG, "  Timeout: %" PRIu32 " µs", this->timeout_us_);
  LOG_UPDATE_INTERVAL(this);
}
float UltrasonicSensorComponent::us_to_m(uint32_t us) {
  const float speed_sound_m_per_s = 343.0f;
  const float time_s = us / 1e6f;
  const float total_dist = time_s * speed_sound_m_per_s;
  return total_dist / 2.0f;
}
float UltrasonicSensorComponent::get_setup_priority() const { return setup_priority::DATA; }
void UltrasonicSensorComponent::set_pulse_time_us(uint32_t pulse_time_us) { this->pulse_time_us_ = pulse_time_us; }
void UltrasonicSensorComponent::set_timeout_us(uint32_t timeout_us) { this->timeout_us_ = timeout_us; }

}  // namespace ultrasonic
}  // namespace esphome