max17048.cpp

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#include "max17048.h"
#include "esphome/core/log.h"
 
namespace esphome::max17048 {
 
// MAX17048/MAX17049 1 and 2 cell fuel gauges with ModelGauge
// Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX17048-MAX17049.pdf
 
ESPHOME_LOG_TAG(TAG, "max17048");
 
static constexpr uint8_t REG_VCELL = 0x02;    // cell voltage
static constexpr uint8_t REG_SOC = 0x04;      // state of charge
static constexpr uint8_t REG_VERSION = 0x08;  // 0x001x
static constexpr uint8_t REG_CRATE = 0x16;    // charge rate, signed
 
static constexpr uint16_t VERSION_MASK = 0xFFF0;
static constexpr uint16_t VERSION_FAMILY = 0x0010;
 
static constexpr float VCELL_VOLTS_PER_LSB = 78.125e-6f;
static constexpr float SOC_PERCENT_PER_LSB = 1.0f / 256.0f;
static constexpr float CRATE_PERCENT_PER_HOUR_PER_LSB = 0.208f;
 
void MAX17048Component::setup() {
  uint16_t version;
  if (!this->read_byte_16(REG_VERSION, &version)) {
    this->mark_failed(LOG_STR(ESP_LOG_MSG_COMM_FAIL));
    return;
  }
  if ((version & VERSION_MASK) != VERSION_FAMILY) {
    ESP_LOGW(TAG, "Unexpected version 0x%04X", version);
  }
}
 
void MAX17048Component::update() {
  bool ok = true;
  uint16_t raw;
  if (this->battery_voltage_sensor_ != nullptr) {
    if (this->read_byte_16(REG_VCELL, &raw)) {
      this->battery_voltage_sensor_->publish_state(raw * VCELL_VOLTS_PER_LSB);
    } else {
      ok = false;
    }
  }
  if (this->battery_level_sensor_ != nullptr) {
    if (this->read_byte_16(REG_SOC, &raw)) {
      this->battery_level_sensor_->publish_state(raw * SOC_PERCENT_PER_LSB);
    } else {
      ok = false;
    }
  }
  if (this->rate_sensor_ != nullptr) {
    if (this->read_byte_16(REG_CRATE, &raw)) {
      this->rate_sensor_->publish_state(static_cast<int16_t>(raw) * CRATE_PERCENT_PER_HOUR_PER_LSB);
    } else {
      ok = false;
    }
  }
  if (ok) {
    this->status_clear_warning();
  } else {
    this->status_set_warning(LOG_STR("Register read failed"));
  }
}
 
void MAX17048Component::dump_config() {
  ESP_LOGCONFIG(TAG, "MAX17048:");
  LOG_I2C_DEVICE(this);
  LOG_UPDATE_INTERVAL(this);
  LOG_SENSOR("  ", "Battery Voltage", this->battery_voltage_sensor_);
  LOG_SENSOR("  ", "Battery Level", this->battery_level_sensor_);
  LOG_SENSOR("  ", "Rate", this->rate_sensor_);
}
 
}  // namespace esphome::max17048