text: #include "max31856.h"
  
  #include "esphome/core/log.h"
  #include <cmath>
  
  namespace esphome {
  namespace max31856 {
  
  static const char *const TAG = "max31856";
  
  // Based on Adafruit's library: https://github.com/adafruit/Adafruit_MAX31856
  
  void MAX31856Sensor::setup() {
    ESP_LOGCONFIG(TAG, "Setting up MAX31856Sensor '%s'...", this->name_.c_str());
    this->spi_setup();
  
    // assert on any fault
    ESP_LOGCONFIG(TAG, "Setting up assertion on all faults");
    this->write_register_(MAX31856_MASK_REG, 0x0);
  
    ESP_LOGCONFIG(TAG, "Setting up open circuit fault detection");
    this->write_register_(MAX31856_CR0_REG, MAX31856_CR0_OCFAULT01);
  
    this->set_thermocouple_type_();
    this->set_noise_filter_();
  
    ESP_LOGCONFIG(TAG, "Completed setting up MAX31856Sensor '%s'...", this->name_.c_str());
  }
  
  void MAX31856Sensor::dump_config() {
    LOG_SENSOR("", "MAX31856", this);
    LOG_PIN("  CS Pin: ", this->cs_);
    ESP_LOGCONFIG(TAG, "  Mains Filter: %s",
                  (filter_ == FILTER_60HZ ? "60 Hz" : (filter_ == FILTER_50HZ ? "50 Hz" : "Unknown!")));
    LOG_UPDATE_INTERVAL(this);
  }
  
  void MAX31856Sensor::update() {
    ESP_LOGVV(TAG, "update");
  
    this->one_shot_temperature_();
  
    // Datasheet max conversion time for 1 shot is 155ms for 60Hz / 185ms for 50Hz
    auto f = std::bind(&MAX31856Sensor::read_thermocouple_temperature_, this);
    this->set_timeout("MAX31856Sensor::read_thermocouple_temperature_", filter_ == FILTER_60HZ ? 155 : 185, f);
  }
  
  void MAX31856Sensor::read_thermocouple_temperature_() {
    if (this->has_fault_()) {
      // Faults have been logged, clear it for next loop
      this->clear_fault_();
    } else {
      int32_t temp24 = this->read_register24_(MAX31856_LTCBH_REG);
      if (temp24 & 0x800000) {
        temp24 |= 0xFF000000;  // fix sign
      }
  
      temp24 >>= 5;  // bottom 5 bits are unused
  
      float temp_c = temp24;
      temp_c *= 0.0078125;
  
      ESP_LOGD(TAG, "Got thermocouple temperature: %.2f°C", temp_c);
      this->publish_state(temp_c);
    }
  }
  
  void MAX31856Sensor::one_shot_temperature_() {
    ESP_LOGVV(TAG, "one_shot_temperature_");
    this->write_register_(MAX31856_CJTO_REG, 0x0);
  
    uint8_t t = this->read_register_(MAX31856_CR0_REG);
  
    t &= ~MAX31856_CR0_AUTOCONVERT;  // turn off autoconversion mode
    t |= MAX31856_CR0_1SHOT;         // turn on one shot mode
  
    this->write_register_(MAX31856_CR0_REG, t);
  }
  
  bool MAX31856Sensor::has_fault_() {
    ESP_LOGVV(TAG, "read_fault_");
    uint8_t faults = this->read_register_(MAX31856_SR_REG);
  
    if (faults == 0) {
      ESP_LOGV(TAG, "status_set_warning");
      this->status_clear_warning();
      return false;
    }
  
    ESP_LOGV(TAG, "status_set_warning");
    this->status_set_warning();
  
    if ((faults & MAX31856_FAULT_CJRANGE) == MAX31856_FAULT_CJRANGE) {
      ESP_LOGW(TAG, "Cold Junction Out-of-Range: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_TCRANGE) == MAX31856_FAULT_TCRANGE) {
      ESP_LOGW(TAG, "Thermocouple Out-of-Range: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_CJHIGH) == MAX31856_FAULT_CJHIGH) {
      ESP_LOGW(TAG, "Cold-Junction High Fault: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_CJLOW) == MAX31856_FAULT_CJLOW) {
      ESP_LOGW(TAG, "Cold-Junction Low Fault: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_TCHIGH) == MAX31856_FAULT_TCHIGH) {
      ESP_LOGW(TAG, "Thermocouple Temperature High Fault: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_TCLOW) == MAX31856_FAULT_TCLOW) {
      ESP_LOGW(TAG, "Thermocouple Temperature Low Fault: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_OVUV) == MAX31856_FAULT_OVUV) {
      ESP_LOGW(TAG, "Overvoltage or Undervoltage Input Fault: '%s'...", this->name_.c_str());
    }
    if ((faults & MAX31856_FAULT_OPEN) == MAX31856_FAULT_OPEN) {
      ESP_LOGW(TAG, "Thermocouple Open-Circuit Fault (possibly not connected): '%s'...", this->name_.c_str());
    }
  
    return true;
  }
  
  void MAX31856Sensor::clear_fault_() {
    ESP_LOGV(TAG, "clear_fault_");
    uint8_t t = this->read_register_(MAX31856_CR0_REG);
  
    t |= MAX31856_CR0_FAULT;     // turn on fault interrupt mode
    t |= MAX31856_CR0_FAULTCLR;  // enable the fault status clear bit
  
    this->write_register_(MAX31856_CR0_REG, t);
  }
  
  void MAX31856Sensor::set_thermocouple_type_() {
    MAX31856ThermocoupleType type = MAX31856_TCTYPE_K;
    ESP_LOGCONFIG(TAG, "set_thermocouple_type_: 0x%02X", type);
    uint8_t t = this->read_register_(MAX31856_CR1_REG);
    t &= 0xF0;  // mask off bottom 4 bits
    t |= (uint8_t) type & 0x0F;
    this->write_register_(MAX31856_CR1_REG, t);
  }
  
  void MAX31856Sensor::set_noise_filter_() {
    ESP_LOGCONFIG(TAG, "set_noise_filter_: 0x%02X", filter_);
    uint8_t t = this->read_register_(MAX31856_CR0_REG);
    if (filter_ == FILTER_50HZ) {
      t |= 0x01;
      ESP_LOGCONFIG(TAG, "set_noise_filter_: 50 Hz, t==0x%02X", t);
    } else {
      t &= 0xfe;
      ESP_LOGCONFIG(TAG, "set_noise_filter_: 60 Hz, t==0x%02X", t);
    }
    this->write_register_(MAX31856_CR0_REG, t);
  }
  
  void MAX31856Sensor::write_register_(uint8_t reg, uint8_t value) {
    ESP_LOGVV(TAG, "write_register_ raw reg=0x%02X value=0x%02X", reg, value);
    reg |= SPI_WRITE_M;
    ESP_LOGVV(TAG, "write_register_ masked reg=0x%02X value=0x%02X", reg, value);
    this->enable();
    ESP_LOGVV(TAG, "write_byte reg=0x%02X", reg);
    this->write_byte(reg);
    ESP_LOGVV(TAG, "write_byte value=0x%02X", value);
    this->write_byte(value);
    this->disable();
    ESP_LOGV(TAG, "write_register_ 0x%02X: 0x%02X", reg, value);
  }
  
  uint8_t MAX31856Sensor::read_register_(uint8_t reg) {
    ESP_LOGVV(TAG, "read_register_ 0x%02X", reg);
    this->enable();
    ESP_LOGVV(TAG, "write_byte reg=0x%02X", reg);
    this->write_byte(reg);
    const uint8_t value(this->read_byte());
    ESP_LOGVV(TAG, "read_byte value=0x%02X", value);
    this->disable();
    ESP_LOGV(TAG, "read_register_ reg=0x%02X: value=0x%02X", reg, value);
    return value;
  }
  
  uint32_t MAX31856Sensor::read_register24_(uint8_t reg) {
    ESP_LOGVV(TAG, "read_register_24_ 0x%02X", reg);
    this->enable();
    ESP_LOGVV(TAG, "write_byte reg=0x%02X", reg);
    this->write_byte(reg);
    const uint8_t msb(this->read_byte());
    ESP_LOGVV(TAG, "read_byte msb=0x%02X", msb);
    const uint8_t mid(this->read_byte());
    ESP_LOGVV(TAG, "read_byte mid=0x%02X", mid);
    const uint8_t lsb(this->read_byte());
    ESP_LOGVV(TAG, "read_byte lsb=0x%02X", lsb);
    this->disable();
    const uint32_t value((msb << 16) | (mid << 8) | lsb);
    ESP_LOGV(TAG, "read_register_24_ reg=0x%02X: value=0x%06X", reg, value);
    return value;
  }
  
  float MAX31856Sensor::get_setup_priority() const { return setup_priority::DATA; }
  
  }  // namespace max31856
  }  // namespace esphome
  