hx711.cpp

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#include "hx711.h"
#include "esphome/core/helpers.h"
#include "esphome/core/log.h"
 
namespace esphome::hx711 {
 
ESPHOME_LOG_TAG(TAG, "hx711");
 
void HX711Sensor::setup() {
  this->sck_pin_->setup();
  this->dout_pin_->setup();
  this->sck_pin_->digital_write(false);
 
  // Read sensor once without publishing to set the gain
  this->read_sensor_(nullptr);
}
 
void HX711Sensor::dump_config() {
  LOG_SENSOR("", "HX711", this);
  LOG_PIN("  DOUT Pin: ", this->dout_pin_);
  LOG_PIN("  SCK Pin: ", this->sck_pin_);
  LOG_UPDATE_INTERVAL(this);
}
void HX711Sensor::update() {
  uint32_t result;
  if (this->read_sensor_(&result)) {
    int32_t value = static_cast<int32_t>(result);
    ESP_LOGD(TAG, "'%s': Got value %" PRId32, LOG_STR_ARG(this->get_log_name()), value);
    this->publish_state(value);
  }
}
bool HX711Sensor::read_sensor_(uint32_t *result) {
  if (this->dout_pin_->digital_read()) {
    ESP_LOGW(TAG, "HX711 is not ready for new measurements yet!");
    this->status_set_warning();
    return false;
  }
 
  uint32_t data = 0;
  bool final_dout;
 
  {
    InterruptLock lock;
    for (uint8_t i = 0; i < 24; i++) {
      this->sck_pin_->digital_write(true);
      delayMicroseconds(1);
      data |= uint32_t(this->dout_pin_->digital_read()) << (23 - i);
      this->sck_pin_->digital_write(false);
      delayMicroseconds(1);
    }
 
    // Cycle clock pin for gain setting
    for (uint8_t i = 0; i < static_cast<uint8_t>(this->gain_); i++) {
      this->sck_pin_->digital_write(true);
      delayMicroseconds(1);
      this->sck_pin_->digital_write(false);
      delayMicroseconds(1);
    }
    final_dout = this->dout_pin_->digital_read();
  }
 
  if (!this->status_comm_result(final_dout)) {
    ESP_LOGW(TAG, "HX711 DOUT pin not high after reading (data 0x%" PRIx32 ")!", data);
    return false;
  }
 
  data = static_cast<uint32_t>(sign_extend<24>(data));
 
  if (result != nullptr)
    *result = data;
  return true;
}
 
}  // namespace esphome::hx711