Adafruit_ADS1X15.cpp

/**************************************************************************/
/*!
    @file     Adafruit_ADS1X15.cpp
    @author   K.Townsend (Adafruit Industries)

    @mainpage Adafruit ADS1X15 ADC Breakout Driver

    @section intro_sec Introduction

    This is a library for the Adafruit ADS1X15 ADC breakout boards.

    Adafruit invests time and resources providing this open source code,
    please support Adafruit and open-source hardware by purchasing
    products from Adafruit!

    @section author Author

    Written by Kevin "KTOWN" Townsend for Adafruit Industries.

    @section  HISTORY

    v1.0  - First release
    v1.1  - Added ADS1115 support - W. Earl
    v2.0  - Refactor - C. Nelson

    @section license License

    BSD license, all text here must be included in any redistribution
*/
/**************************************************************************/
#include "Adafruit_ADS1X15.h"
/*
 * 
 * #include <Adafruit_ADS1X15.h>
 * 
 
 */

 

/**************************************************************************/
/*!
    @brief  Instantiates a new ADS1015 class w/appropriate properties
*/
/**************************************************************************/
Adafruit_ADS1015::Adafruit_ADS1015() {
  _m_bitShift = 4;
  _m_gain  = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
   _m_dataRate = RATE_ADS1015_1600SPS;
}

/**************************************************************************/
/*!
    @brief  Instantiates a new ADS1115 class w/appropriate properties
*/
/**************************************************************************/
Adafruit_ADS1115::Adafruit_ADS1115() {
  _m_bitShift = 0;
  _m_gain  = GAIN_TWOTHIRDS; /* +/- 6.144V range (limited to VDD +0.3V max!) */
   _m_dataRate = RATE_ADS1115_128SPS;
}

/**************************************************************************/
/*!
    @brief  Sets up the HW (reads coefficients values, etc.)

    @param i2c_addr I2C address of device
    @param wire I2C bus

    @return true if successful, otherwise false
*/
// ************************************************************************ 
bool Adafruit_ADS1X15::begin(uint8_t i2c_addr, i2c_port_t i2c_channel) {

   esp_err_t espRc;
   

  _i2c_addr =  i2c_addr ;            // inicializo la variable protegida con el valor recibido de la dirección del dispositivo
  _i2c_channel = i2c_channel;

    // Check if there is a device assigned to the address reveived
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (i2c_addr << 1) | I2C_MASTER_WRITE, 1 /* expect ack */);
    i2c_master_stop(cmd);
    espRc = i2c_master_cmd_begin(_i2c_channel, cmd, 10/portTICK_PERIOD_MS);
    i2c_cmd_link_delete(cmd);
    
    if (espRc == 0) {
      return true;          //  device found
    } else {
      return false;
    }

}
 

/**************************************************************************/
/*!
    @brief  Sets the gain and input voltage range

    @param gain gain setting to use
*/
/**************************************************************************/
void Adafruit_ADS1X15::setGain(adsGain_t gain) { _m_gain  = gain; }

/**************************************************************************/
/*!
    @brief  Gets a gain and input voltage range

    @return the gain setting
*/
/**************************************************************************/
adsGain_t Adafruit_ADS1X15::getGain() { return _m_gain ; }

/**************************************************************************/
/*!
    @brief  Sets the data rate

    @param rate the data rate to use
*/
/**************************************************************************/
void Adafruit_ADS1X15::setDataRate(uint16_t rate) {  _m_dataRate = rate; }

/**************************************************************************/
/*!
    @brief  Gets the current data rate

    @return the data rate
*/
/**************************************************************************/
uint16_t Adafruit_ADS1X15::getDataRate() { return  _m_dataRate; }

/**************************************************************************/
/*!
    @brief  Gets a single-ended ADC reading from the specified channel

    @param channel ADC channel to read

    @return the ADC reading
*/
/**************************************************************************/
int16_t Adafruit_ADS1X15::readADC_SingleEnded(uint8_t channel) {
  if (channel > 3) {
    return 0;
  }

  // Start with default values
  uint16_t config =
      ADS1X15_REG_CONFIG_CQUE_NONE |    // Disable the comparator (default val)
      ADS1X15_REG_CONFIG_CLAT_NONLAT |  // Non-latching (default val)
      ADS1X15_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low   (default val)
      ADS1X15_REG_CONFIG_CMODE_TRAD |   // Traditional comparator (default val)
      ADS1X15_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (default)

  // Set PGA/voltage range
  config |= _m_gain ;

  // Set data rate
  config |=  _m_dataRate;

  // Set single-ended input channel
  switch (channel) {
  case (0):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_0;
    break;
  case (1):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_1;
    break;
  case (2):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_2;
    break;
  case (3):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_3;
    break;
  }

  // Set 'start single-conversion' bit
  config |= ADS1X15_REG_CONFIG_OS_SINGLE;

  // Write config register to the ADC
  writeRegister(ADS1X15_REG_POINTER_CONFIG, config);

  // Wait for the conversion to complete
  while (!conversionComplete())
    ;

  // Read the conversion results
  return getLastConversionResults();
}

/**************************************************************************/
/*!
    @brief  Reads the conversion results, measuring the voltage
            difference between the P (AIN0) and N (AIN1) input.  Generates
            a signed value since the difference can be either
            positive or negative.

    @return the ADC reading
*/
/**************************************************************************/
int16_t Adafruit_ADS1X15::readADC_Differential_0_1() {
  // Start with default values
  uint16_t config =
      ADS1X15_REG_CONFIG_CQUE_NONE |    // Disable the comparator (default val)
      ADS1X15_REG_CONFIG_CLAT_NONLAT |  // Non-latching (default val)
      ADS1X15_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low   (default val)
      ADS1X15_REG_CONFIG_CMODE_TRAD |   // Traditional comparator (default val)
      ADS1X15_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (default)

  // Set PGA/voltage range
  config |= _m_gain ;

  // Set data rate
  config |=  _m_dataRate;

  // Set channels
  config |= ADS1X15_REG_CONFIG_MUX_DIFF_0_1; // AIN0 = P, AIN1 = N

  // Set 'start single-conversion' bit
  config |= ADS1X15_REG_CONFIG_OS_SINGLE;

  // Write config register to the ADC
  writeRegister(ADS1X15_REG_POINTER_CONFIG, config);

  // Wait for the conversion to complete
  while (!conversionComplete())
    ;

  // Read the conversion results
  return getLastConversionResults();
}

/**************************************************************************/
/*!
    @brief  Reads the conversion results, measuring the voltage
            difference between the P (AIN2) and N (AIN3) input.  Generates
            a signed value since the difference can be either
            positive or negative.

    @return the ADC reading
*/
/**************************************************************************/
int16_t Adafruit_ADS1X15::readADC_Differential_2_3() {
  // Start with default values
  uint16_t config =
      ADS1X15_REG_CONFIG_CQUE_NONE |    // Disable the comparator (default val)
      ADS1X15_REG_CONFIG_CLAT_NONLAT |  // Non-latching (default val)
      ADS1X15_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low   (default val)
      ADS1X15_REG_CONFIG_CMODE_TRAD |   // Traditional comparator (default val)
      ADS1X15_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (default)

  // Set PGA/voltage range
  config |= _m_gain ;

  // Set data rate
  config |=  _m_dataRate;

  // Set channels
  config |= ADS1X15_REG_CONFIG_MUX_DIFF_2_3; // AIN2 = P, AIN3 = N

  // Set 'start single-conversion' bit
  config |= ADS1X15_REG_CONFIG_OS_SINGLE;

  // Write config register to the ADC
  writeRegister(ADS1X15_REG_POINTER_CONFIG, config);

  // Wait for the conversion to complete
  while (!conversionComplete())
    ;

  // Read the conversion results
  return getLastConversionResults();
}

/**************************************************************************/
/*!
    @brief  Sets up the comparator to operate in basic mode, causing the
            ALERT/RDY pin to assert (go from high to low) when the ADC
            value exceeds the specified threshold.

            This will also set the ADC in continuous conversion mode.

    @param channel ADC channel to use
    @param threshold comparator threshold
*/
/**************************************************************************/
void Adafruit_ADS1X15::startComparator_SingleEnded(uint8_t channel,
                                                   int16_t threshold) {
  // Start with default values
  uint16_t config =
      ADS1X15_REG_CONFIG_CQUE_1CONV |   // Comparator enabled and asserts on 1
                                        // match
      ADS1X15_REG_CONFIG_CLAT_LATCH |   // Latching mode
      ADS1X15_REG_CONFIG_CPOL_ACTVLOW | // Alert/Rdy active low   (default val)
      ADS1X15_REG_CONFIG_CMODE_TRAD |   // Traditional comparator (default val)
      ADS1X15_REG_CONFIG_MODE_CONTIN |  // Continuous conversion mode
      ADS1X15_REG_CONFIG_MODE_CONTIN;   // Continuous conversion mode

  // Set PGA/voltage range
  config |= _m_gain ;

  // Set data rate
  config |=  _m_dataRate;

  // Set single-ended input channel
  switch (channel) {
  case (0):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_0;
    break;
  case (1):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_1;
    break;
  case (2):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_2;
    break;
  case (3):
    config |= ADS1X15_REG_CONFIG_MUX_SINGLE_3;
    break;
  }

  // Set the high threshold register
  // Shift 12-bit results left 4 bits for the ADS1015
  writeRegister(ADS1X15_REG_POINTER_HITHRESH, threshold << _m_bitShift);

  // Write config register to the ADC
  writeRegister(ADS1X15_REG_POINTER_CONFIG, config);
}

/**************************************************************************/
/*!
    @brief  In order to clear the comparator, we need to read the
            conversion results.  This function reads the last conversion
            results without changing the config value.

    @return the last ADC reading
*/
/**************************************************************************/
int16_t Adafruit_ADS1X15::getLastConversionResults() {

   // Read the conversion results
  uint16_t res = readRegister(ADS1X15_REG_POINTER_CONVERT) >> _m_bitShift;
  
  
  if (_m_bitShift == 0) {
    return (int16_t)res;
  } else {
    // Shift 12-bit results right 4 bits for the ADS1015,
    // making sure we keep the sign bit intact
    if (res > 0x07FF) {
      // negative number - extend the sign to 16th bit
      res |= 0xF000;
    }


    return (int16_t)res;
  }
}

/**************************************************************************/
/*!
    @brief  Returns true if conversion is complete, false otherwise.

    @param counts the ADC reading in raw counts

    @return the ADC reading in volts
*/
/**************************************************************************/
float Adafruit_ADS1X15::computeVolts(int16_t counts) {
  // see data sheet Table 3
  float fsRange;
  switch (_m_gain ) {
  case GAIN_TWOTHIRDS:
    fsRange = 6.144f;
    break;
  case GAIN_ONE:
    fsRange = 4.096f;
    break;
  case GAIN_TWO:
    fsRange = 2.048f;
    break;
  case GAIN_FOUR:
    fsRange = 1.024f;
    break;
  case GAIN_EIGHT:
    fsRange = 0.512f;
    break;
  case GAIN_SIXTEEN:
    fsRange = 0.256f;
    break;
  default:
    fsRange = 0.0f;
  }
  return counts * (fsRange / (32768 >> _m_bitShift));
}

/**************************************************************************/
/*!
    @brief  Returns true if conversion is complete, false otherwise.
*/
/**************************************************************************/
bool Adafruit_ADS1X15::conversionComplete() {

 
  return (readRegister(ADS1X15_REG_POINTER_CONFIG) & 0x8000) != 0;
}

/**************************************************************************/
/*!
    @brief  Writes 16-bits to the specified destination register

    @param reg register address to write to
    @param value value to write to register
*/
/**************************************************************************/
void Adafruit_ADS1X15::writeRegister(uint8_t reg, uint16_t value) {
  
  _buffer[0] = reg;
  _buffer[1] = value >> 8;
  _buffer[2] = value & 0xFF;

    i2c_cmd_handle_t cmd;
     
    cmd = i2c_cmd_link_create();
    ESP_ERROR_CHECK(i2c_master_start(cmd));
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, (_i2c_addr<<1) |I2C_MASTER_WRITE, 1));
     
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, _buffer[0], 1));
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, _buffer[1], 1)); // 0x83
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, _buffer[2], 1));
    ESP_ERROR_CHECK(i2c_master_stop(cmd));
    ESP_ERROR_CHECK(i2c_master_cmd_begin(_i2c_channel, cmd, 1000/portTICK_RATE_MS));
    i2c_cmd_link_delete(cmd);




  
  //m_i2c_dev->write(_buffer, 3);
  

}

/**************************************************************************/
/*!
    @brief  Read 16-bits from the specified destination register

    @param reg register address to read from

    @return 16 bit register value read
*/
/**************************************************************************/
uint16_t Adafruit_ADS1X15::readRegister(uint8_t reg) {
  uint16_t parcial;

    i2c_cmd_handle_t cmd;

    //uint16_t val;
 
  _buffer[0] = reg;

    cmd = i2c_cmd_link_create();
    ESP_ERROR_CHECK(i2c_master_start(cmd));
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, (_i2c_addr<<1)|I2C_MASTER_WRITE, 1));
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, reg, 1));
    ESP_ERROR_CHECK(i2c_master_stop(cmd));
    ESP_ERROR_CHECK(i2c_master_cmd_begin(_i2c_channel, cmd, 1000/portTICK_RATE_MS));
    i2c_cmd_link_delete(cmd);

    cmd = i2c_cmd_link_create();
    ESP_ERROR_CHECK(i2c_master_start(cmd));
    ESP_ERROR_CHECK(i2c_master_write_byte(cmd, (_i2c_addr<<1)|I2C_MASTER_READ, 1));
 
    ESP_ERROR_CHECK(i2c_master_read(cmd, (uint8_t *)&_buffer, 2 ,(i2c_ack_type_t) 0));
    ESP_ERROR_CHECK(i2c_master_stop(cmd));
    ESP_ERROR_CHECK(i2c_master_cmd_begin(_i2c_channel, cmd, 1000/portTICK_RATE_MS));
    i2c_cmd_link_delete(cmd);




 
  return ((_buffer[0] << 8) | _buffer[1]);

  
}