Adafruit_INA2xx.cpp

/*!
 *  @file Adafruit_INA2xx.cpp
 *
 *  @section ina2xx_intro Introduction
 *
 * 	I2C Driver base class for the INA2xx I2C Current and Power sensors
 *
 * 	This is a library for the Adafruit INA228 breakout:
 * 	http://www.adafruit.com/products/5832
 *
 * 	Adafruit invests time and resources providing this open source code,
 *  please support Adafruit and open-source hardware by purchasing products from
 * 	Adafruit!
 *
 *  @section ina2xx_dependencies Dependencies
 *
 *  This library depends on the Adafruit BusIO library
 *
 *  @section ina2xx_author Author
 *
 *  Bryan Siepert for Adafruit Industries
 *
 * 	@section ina2xx_license License
 *
 * 	BSD (see license.txt)
 *
 * 	@section ina2xx_history HISTORY
 *
 *     v1.0 - First release
 */

#include "Adafruit_INA2xx.h"

#include <Wire.h>

#include "Arduino.h"

/*!
 *    @brief  Instantiates a new INA2xx class
 */
Adafruit_INA2xx::Adafruit_INA2xx(void) {}

/*!
 *    @brief  Sets up the HW
 *    @param  i2c_address
 *            The I2C address to be used.
 *    @param  theWire
 *            The Wire object to be used for I2C connections.
 *    @param  skipReset
 *            When set to true, will omit resetting all registers to
 *            their default values. Default: false.
 *    @return True if initialization was successful (including verifying
 *            the manufacturer ID is Texas Instruments: 0x5449), otherwise
 * false.
 */
bool Adafruit_INA2xx::begin(uint8_t i2c_address, TwoWire* theWire,
                            bool skipReset) {
  i2c_dev = new Adafruit_I2CDevice(i2c_address, theWire);

  if (!i2c_dev->begin()) {
    return false;
  }

  Adafruit_I2CRegister* device_register =
      new Adafruit_I2CRegister(i2c_dev, INA2XX_REG_DVC_UID, 2, MSBFIRST);
  Adafruit_I2CRegister* mfg_register =
      new Adafruit_I2CRegister(i2c_dev, INA2XX_REG_MFG_UID, 2, MSBFIRST);
  Adafruit_I2CRegisterBits* device_id =
      new Adafruit_I2CRegisterBits(device_register, 12, 4);

  // Check manufacturer ID (should be 0x5449 for Texas Instruments)
  uint16_t mfg_id = mfg_register->read();
  if (mfg_id != 0x5449) {
    return false;
  }

  // Store device ID for validation in derived classes
  _device_id = device_id->read();

  Config = new Adafruit_I2CRegister(i2c_dev, INA2XX_REG_CONFIG, 2, MSBFIRST);
  ADC_Config =
      new Adafruit_I2CRegister(i2c_dev, INA2XX_REG_ADCCFG, 2, MSBFIRST);
  Diag_Alert =
      new Adafruit_I2CRegister(i2c_dev, INA2XX_REG_DIAGALRT, 2, MSBFIRST);

  if (!skipReset) {
    reset();
    delay(2); // delay 2ms to give time for first measurement to finish
  }
  return true;
}
/**************************************************************************/
/*!
    @brief Resets the hardware. All registers are set to default values,
    the same as a power-on reset.
*/
/**************************************************************************/
void Adafruit_INA2xx::reset(void) {
  Adafruit_I2CRegisterBits reset = Adafruit_I2CRegisterBits(Config, 1, 15);
  reset.write(1);
  Adafruit_I2CRegisterBits alert_conv =
      Adafruit_I2CRegisterBits(Diag_Alert, 1, 14);
  alert_conv.write(1);
  setMode(INA2XX_MODE_CONTINUOUS);
}

/**************************************************************************/
/*!
    @brief Updates the shunt calibration value to the register.
    This is implemented in the derived classes due to different calculations
*/
/**************************************************************************/
void Adafruit_INA2xx::_updateShuntCalRegister() {
  // Implemented in derived classes
}

/**************************************************************************/
/*!
    @brief Sets the shunt calibration by resistor.
    @note This base implementation uses INA228 settings.
          Derived classes override this method for their specific settings.
    @param shunt_res Resistance of the shunt in ohms (floating point)
    @param max_current Maximum expected current in A (floating point)
*/
/**************************************************************************/
void Adafruit_INA2xx::setShunt(float shunt_res, float max_current) {
  _shunt_res = shunt_res;
  // Default to INA228 behavior (2^19 divisor)
  _current_lsb = max_current / (float)(1UL << 19);
  _updateShuntCalRegister();
}

/**************************************************************************/
/*!
    @brief Sets the shunt full scale ADC range across IN+ and IN-.
    @param adc_range
          Shunt full scale ADC range (0: +/-163.84 mV or 1: +/-40.96 mV)
*/
/**************************************************************************/
void Adafruit_INA2xx::setADCRange(uint8_t adc_range) {
  Adafruit_I2CRegisterBits adc_range_bit =
      Adafruit_I2CRegisterBits(Config, 1, 4);
  adc_range_bit.write(adc_range);
  _updateShuntCalRegister();
}

/**************************************************************************/
/*!
    @brief Reads the shunt full scale ADC range across IN+ and IN-.
    @return Shunt full scale ADC range (0: +/-163.84 mV or 1: +/-40.96 mV)
*/
/**************************************************************************/
uint8_t Adafruit_INA2xx::getADCRange() {
  return (Config->read() >> 4) & 1;
}

/**************************************************************************/
/*!
    @brief Reads the die temperature (using INA228 scale factor by default)
    @note This base implementation uses the INA228 conversion factor of 7.8125
   m°C/LSB. Derived classes override this method as needed (e.g., INA237).
    @return The current die temp in deg C
*/
/**************************************************************************/
float Adafruit_INA2xx::readDieTemp(void) {
  Adafruit_I2CRegister temp =
      Adafruit_I2CRegister(i2c_dev, INA2XX_REG_DIETEMP, 2, MSBFIRST);
  int16_t t = temp.read();
  // INA228 uses 16 bits for temperature with 7.8125 m°C/LSB
  return (float)t * 7.8125 / 1000.0;
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Current register.
    @return The current current measurement in mA
*/
/**************************************************************************/
float Adafruit_INA2xx::readCurrent(void) {
  Adafruit_I2CRegister current =
      Adafruit_I2CRegister(i2c_dev, INA2XX_REG_CURRENT, 3, MSBFIRST);
  int32_t i = current.read();
  if (i & 0x800000)
    i |= 0xFF000000;
  return (float)i / 16.0 * _current_lsb * 1000.0;
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Current register.
    @return The current current measurement in mA
*/
/**************************************************************************/
float Adafruit_INA2xx::getCurrent_mA(void) {
  return readCurrent();
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Bus Voltage register.
    @note This base implementation uses the INA228 conversion factor.
          Derived classes override this method for their specific conversion
   factors.
    @return The current bus voltage measurement in V
*/
/**************************************************************************/
float Adafruit_INA2xx::readBusVoltage(void) {
  Adafruit_I2CRegister bus_voltage =
      Adafruit_I2CRegister(i2c_dev, INA2XX_REG_VBUS, 3, MSBFIRST);
  // INA228 uses 195.3125 µV/LSB (microvolts) for bus voltage,
  // so we need to divide by 1e6 to get Volts
  return (float)((uint32_t)bus_voltage.read() >> 4) * 195.3125 / 1e6;
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Bus Voltage register.
    @return The current bus voltage measurement in V
*/
/**************************************************************************/
float Adafruit_INA2xx::getBusVoltage_V(void) {
  return readBusVoltage();
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Shunt Voltage register.
    @return The current shunt voltage measurement in mV
*/
/**************************************************************************/
float Adafruit_INA2xx::readShuntVoltage(void) {
  float scale = 312.5;
  if (getADCRange()) {
    scale = 78.125;
  }

  Adafruit_I2CRegister shunt_voltage =
      Adafruit_I2CRegister(i2c_dev, INA2XX_REG_VSHUNT, 3, MSBFIRST);
  int32_t v = shunt_voltage.read();
  if (v & 0x800000)
    v |= 0xFF000000;
  return (float)v / 16.0 * scale / 1000000.0;
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Shunt Voltage register.
    @return The current shunt voltage measurement in mV
*/
/**************************************************************************/
float Adafruit_INA2xx::getShuntVoltage_mV(void) {
  return readShuntVoltage();
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Power register.
    @return The current Power calculation in mW
*/
/**************************************************************************/
float Adafruit_INA2xx::readPower(void) {
  Adafruit_I2CRegister power =
      Adafruit_I2CRegister(i2c_dev, INA2XX_REG_POWER, 3, MSBFIRST);
  return (float)power.read() * 3.2 * _current_lsb * 1000;
}

/**************************************************************************/
/*!
    @brief Reads and scales the current value of the Power register.
    @return The current Power calculation in mW
*/
/**************************************************************************/
float Adafruit_INA2xx::getPower_mW(void) {
  return readPower();
}

/**************************************************************************/
/*!
    @brief Returns the current measurement mode
    @return The current mode
*/
/**************************************************************************/
INA2XX_MeasurementMode Adafruit_INA2xx::getMode(void) {
  Adafruit_I2CRegisterBits mode = Adafruit_I2CRegisterBits(ADC_Config, 4, 12);
  return (INA2XX_MeasurementMode)mode.read();
}
/**************************************************************************/
/*!
    @brief Sets a new measurement mode
    @param new_mode
          The new mode to be set
*/
/**************************************************************************/
void Adafruit_INA2xx::setMode(INA2XX_MeasurementMode new_mode) {
  Adafruit_I2CRegisterBits mode = Adafruit_I2CRegisterBits(ADC_Config, 4, 12);
  mode.write(new_mode);
}
/**************************************************************************/
/*!
    @brief Reads the current number of averaging samples
    @return The current number of averaging samples
*/
/**************************************************************************/
INA2XX_AveragingCount Adafruit_INA2xx::getAveragingCount(void) {
  Adafruit_I2CRegisterBits averaging_count =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 0);
  return (INA2XX_AveragingCount)averaging_count.read();
}
/**************************************************************************/
/*!
    @brief Sets the number of averaging samples
    @param count
          The number of samples to be averaged
*/
/**************************************************************************/
void Adafruit_INA2xx::setAveragingCount(INA2XX_AveragingCount count) {
  Adafruit_I2CRegisterBits averaging_count =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 0);
  averaging_count.write(count);
}
/**************************************************************************/
/*!
    @brief Reads the current current conversion time
    @return The current current conversion time
*/
/**************************************************************************/
INA2XX_ConversionTime Adafruit_INA2xx::getCurrentConversionTime(void) {
  Adafruit_I2CRegisterBits current_conversion_time =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 6);
  return (INA2XX_ConversionTime)current_conversion_time.read();
}
/**************************************************************************/
/*!
    @brief Sets the current conversion time
    @param time
          The new current conversion time
*/
/**************************************************************************/
void Adafruit_INA2xx::setCurrentConversionTime(INA2XX_ConversionTime time) {
  Adafruit_I2CRegisterBits current_conversion_time =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 6);
  current_conversion_time.write(time);
}
/**************************************************************************/
/*!
    @brief Reads the current bus voltage conversion time
    @return The current bus voltage conversion time
*/
/**************************************************************************/
INA2XX_ConversionTime Adafruit_INA2xx::getVoltageConversionTime(void) {
  Adafruit_I2CRegisterBits voltage_conversion_time =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 9);
  return (INA2XX_ConversionTime)voltage_conversion_time.read();
}
/**************************************************************************/
/*!
    @brief Sets the bus voltage conversion time
    @param time
          The new bus voltage conversion time
*/
/**************************************************************************/
void Adafruit_INA2xx::setVoltageConversionTime(INA2XX_ConversionTime time) {
  Adafruit_I2CRegisterBits voltage_conversion_time =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 9);
  voltage_conversion_time.write(time);
}
/**************************************************************************/
/*!
    @brief Reads the temperature conversion time
    @return The temperature conversion time
*/
/**************************************************************************/
INA2XX_ConversionTime Adafruit_INA2xx::getTemperatureConversionTime(void) {
  Adafruit_I2CRegisterBits temperature_conversion_time =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 3);
  return (INA2XX_ConversionTime)temperature_conversion_time.read();
}
/**************************************************************************/
/*!
    @brief Sets the temperature conversion time
    @param time
          The new temperature conversion time
*/
/**************************************************************************/
void Adafruit_INA2xx::setTemperatureConversionTime(INA2XX_ConversionTime time) {
  Adafruit_I2CRegisterBits temperature_conversion_time =
      Adafruit_I2CRegisterBits(ADC_Config, 3, 3);
  temperature_conversion_time.write(time);
}

/**************************************************************************/
/*!
    @brief Checks if the most recent one shot measurement has completed
    @return true if the conversion has completed
*/
/**************************************************************************/
bool Adafruit_INA2xx::conversionReady(void) {
  Adafruit_I2CRegisterBits conversion_ready =
      Adafruit_I2CRegisterBits(Diag_Alert, 1, 1);
  return conversion_ready.read();
}

/**************************************************************************/
/*!
    @brief Reads the current alert polarity setting
    @return The current bus alert polarity setting
*/
/**************************************************************************/
INA2XX_AlertPolarity Adafruit_INA2xx::getAlertPolarity(void) {
  Adafruit_I2CRegisterBits alert_polarity =
      Adafruit_I2CRegisterBits(Diag_Alert, 1, 12);
  return (INA2XX_AlertPolarity)alert_polarity.read();
}
/**************************************************************************/
/*!
    @brief Sets Alert Polarity Bit
    @param polarity
          The polarity of the alert pin
*/
/**************************************************************************/
void Adafruit_INA2xx::setAlertPolarity(INA2XX_AlertPolarity polarity) {
  Adafruit_I2CRegisterBits alert_polarity =
      Adafruit_I2CRegisterBits(Diag_Alert, 1, 12);
  alert_polarity.write(polarity);
}
/**************************************************************************/
/*!
    @brief Reads the current alert latch setting
    @return The current bus alert latch setting
*/
/**************************************************************************/
INA2XX_AlertLatch Adafruit_INA2xx::getAlertLatch(void) {
  Adafruit_I2CRegisterBits alert_latch =
      Adafruit_I2CRegisterBits(Diag_Alert, 1, 15);
  return (INA2XX_AlertLatch)alert_latch.read();
}
/**************************************************************************/
/*!
    @brief Sets Alert Latch Bit
    @param state
          The parameter which asserts the ALERT pin
*/
/**************************************************************************/
void Adafruit_INA2xx::setAlertLatch(INA2XX_AlertLatch state) {
  Adafruit_I2CRegisterBits alert_latch =
      Adafruit_I2CRegisterBits(Diag_Alert, 1, 15);
  alert_latch.write(state);
}
/**************************************************************************/
/*!
    @brief Reads the alert function flags from DIAG_ALRT
    @return Bits that indicate alert flags
*/
/**************************************************************************/
uint16_t Adafruit_INA2xx::alertFunctionFlags(void) {
  Adafruit_I2CRegisterBits alert_flags =
      Adafruit_I2CRegisterBits(Diag_Alert, 12, 0);
  return alert_flags.read();
}