max6675.cpp

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#include "max6675.h"
#include "esphome/core/log.h"
 
namespace esphome::max6675 {
 
ESPHOME_LOG_TAG(TAG, "max6675");
 
static constexpr uint32_t READ_TIMEOUT_ID = 0;
 
void MAX6675Sensor::update() {
  this->enable();
  delay(1);
  // conversion initiated by rising edge
  this->disable();
 
  // Conversion time typ: 170ms, max: 220ms
  this->set_timeout(READ_TIMEOUT_ID, 250, [this]() { this->read_data_(); });
}
 
void MAX6675Sensor::setup() { this->spi_setup(); }
void MAX6675Sensor::dump_config() {
  LOG_SENSOR("", "MAX6675", this);
  LOG_PIN("  CS Pin: ", this->cs_);
  LOG_UPDATE_INTERVAL(this);
}
void MAX6675Sensor::read_data_() {
  this->enable();
  delay(1);
  uint8_t data[2];
  this->read_array(data, 2);
  uint16_t val = data[1] | (uint16_t(data[0]) << 8);
  this->disable();
 
  // Bit 2 set means the thermocouple is open
  if (!this->status_comm_result((val & 0x04) == 0, nullptr)) {
    ESP_LOGW(TAG, "Got invalid value from MAX6675Sensor (0x%04X)", val);
    return;
  }
 
  float temperature = float(val >> 3) / 4.0f;
  ESP_LOGD(TAG, "'%s': Got temperature=%.1f°C", LOG_STR_ARG(this->get_log_name()), temperature);
  this->publish_state(temperature);
}
 
}  // namespace esphome::max6675