Adafruit_SI1145.cpp

/***************************************************
  This is a library for the Si1145 UV/IR/Visible Light Sensor

  Designed specifically to work with the Si1145 sensor in the
  adafruit shop
  ----> https://www.adafruit.com/products/1777

  These sensors use I2C to communicate, 2 pins are required to
  interface
  Adafruit invests time and resources providing this open source code,
  please support Adafruit and open-source hardware by purchasing
  products from Adafruit!

  Written by Limor Fried/Ladyada for Adafruit Industries.
  BSD license, all text above must be included in any redistribution
 ****************************************************/

#include "Adafruit_SI1145.h"

/**
 * @brief Destructor
 *
 */
Adafruit_SI1145::~Adafruit_SI1145() {
  if (i2c_dev)
    delete i2c_dev;
}
/**
 * @brief Construct a new Adafruit_SI1145::Adafruit_SI1145 object
 *
 */
Adafruit_SI1145::Adafruit_SI1145() {}
/**
 * @brief Initize the driver, specifying the `TwoWire` bus to use
 *
 * @param pBus Pointer to the `TwoWire` I2C bus to use
 * @return boolean true: success false: failure to initialize the sensor
 */
boolean Adafruit_SI1145::begin(TwoWire *pBus) {
  return begin(SI1145_ADDR, pBus);
}
/**
 * @brief Initize the driver, supplying both a `TwoWire` bus and I2C address
 *
 * @param addr The I2C address of the Sensor
 * @param pBus Pointer to the `TwoWire` instance to use
 * @return boolean true: success false: failure to initize the sensor
 */
boolean Adafruit_SI1145::begin(uint8_t addr, TwoWire *pBus) {
  if (i2c_dev)
    delete i2c_dev;
  i2c_dev = new Adafruit_I2CDevice(addr, pBus);
  if (!i2c_dev->begin()) {
    return false;
  }

  uint8_t id = read8(SI1145_REG_PARTID);
  if (id != 0x45)
    return false; // look for SI1145

  reset();

  /***********************************/
  // enable UVindex measurement coefficients!
  write8(SI1145_REG_UCOEFF0, 0x29);
  write8(SI1145_REG_UCOEFF1, 0x89);
  write8(SI1145_REG_UCOEFF2, 0x02);
  write8(SI1145_REG_UCOEFF3, 0x00);

  // enable UV sensor
  writeParam(SI1145_PARAM_CHLIST,
             SI1145_PARAM_CHLIST_ENUV | SI1145_PARAM_CHLIST_ENALSIR |
                 SI1145_PARAM_CHLIST_ENALSVIS | SI1145_PARAM_CHLIST_ENPS1);
  // enable interrupt on every sample
  write8(SI1145_REG_INTCFG, SI1145_REG_INTCFG_INTOE);
  write8(SI1145_REG_IRQEN, SI1145_REG_IRQEN_ALSEVERYSAMPLE);

  /****************************** Prox Sense 1 */

  // program LED current
  write8(SI1145_REG_PSLED21, 0x03); // 20mA for LED 1 only
  writeParam(SI1145_PARAM_PS1ADCMUX, SI1145_PARAM_ADCMUX_LARGEIR);
  // prox sensor #1 uses LED #1
  writeParam(SI1145_PARAM_PSLED12SEL, SI1145_PARAM_PSLED12SEL_PS1LED1);
  // fastest clocks, clock div 1
  writeParam(SI1145_PARAM_PSADCGAIN, 0);
  // take 511 clocks to measure
  writeParam(SI1145_PARAM_PSADCOUNTER, SI1145_PARAM_ADCCOUNTER_511CLK);
  // in prox mode, high range
  writeParam(SI1145_PARAM_PSADCMISC,
             SI1145_PARAM_PSADCMISC_RANGE | SI1145_PARAM_PSADCMISC_PSMODE);

  writeParam(SI1145_PARAM_ALSIRADCMUX, SI1145_PARAM_ADCMUX_SMALLIR);
  // fastest clocks, clock div 1
  writeParam(SI1145_PARAM_ALSIRADCGAIN, 0);
  // take 511 clocks to measure
  writeParam(SI1145_PARAM_ALSIRADCOUNTER, SI1145_PARAM_ADCCOUNTER_511CLK);
  // in high range mode
  writeParam(SI1145_PARAM_ALSIRADCMISC, SI1145_PARAM_ALSIRADCMISC_RANGE);

  // fastest clocks, clock div 1
  writeParam(SI1145_PARAM_ALSVISADCGAIN, 0);
  // take 511 clocks to measure
  writeParam(SI1145_PARAM_ALSVISADCOUNTER, SI1145_PARAM_ADCCOUNTER_511CLK);
  // in high range mode (not normal signal)
  writeParam(SI1145_PARAM_ALSVISADCMISC, SI1145_PARAM_ALSVISADCMISC_VISRANGE);

  /************************/

  // measurement rate for auto
  write8(SI1145_REG_MEASRATE0, 0xFF); // 255 * 31.25uS = 8ms

  // auto run
  write8(SI1145_REG_COMMAND, SI1145_PSALS_AUTO);

  return true;
}
/**
 * @brief Reset the sensor's registers to an initial state
 *
 */
void Adafruit_SI1145::reset() {
  write8(SI1145_REG_MEASRATE0, 0);
  write8(SI1145_REG_MEASRATE1, 0);
  write8(SI1145_REG_IRQEN, 0);
  write8(SI1145_REG_IRQMODE1, 0);
  write8(SI1145_REG_IRQMODE2, 0);
  write8(SI1145_REG_INTCFG, 0);
  write8(SI1145_REG_IRQSTAT, 0xFF);

  write8(SI1145_REG_COMMAND, SI1145_RESET);
  delay(10);
  write8(SI1145_REG_HWKEY, 0x17);

  delay(10);
}

//////////////////////////////////////////////////////

/**
 * @brief Get the current UV reading
 *
 * @return uint16_t The the UV index * 100 (divide by 100 to get the index)
 */
uint16_t Adafruit_SI1145::readUV(void) { return read16(0x2C); }

/**
 * @brief Get the Visible & IR light levels
 *
 * @return uint16_t The Visible & IR light levels
 */
uint16_t Adafruit_SI1145::readVisible(void) { return read16(0x22); }

// returns IR light levels
/**
 * @brief Get the Infrared light level
 *
 * @return uint16_t The Infrared light level
 */
uint16_t Adafruit_SI1145::readIR(void) { return read16(0x24); }

// returns "Proximity" - assumes an IR LED is attached to LED
/**
 * @brief Gets the Proximity measurement - **Requires an attached IR LED**
 *
 * @return uint16_t The proximity measurement
 */
uint16_t Adafruit_SI1145::readProx(void) { return read16(0x26); }

/*********************************************************************/

uint8_t Adafruit_SI1145::writeParam(uint8_t p, uint8_t v) {
  // Serial.print("Param 0x"); Serial.print(p, HEX);
  // Serial.print(" = 0x"); Serial.println(v, HEX);

  write8(SI1145_REG_PARAMWR, v);
  write8(SI1145_REG_COMMAND, p | SI1145_PARAM_SET);
  return read8(SI1145_REG_PARAMRD);
}

uint8_t Adafruit_SI1145::readParam(uint8_t p) {
  write8(SI1145_REG_COMMAND, p | SI1145_PARAM_QUERY);
  return read8(SI1145_REG_PARAMRD);
}

/*********************************************************************/

uint8_t Adafruit_SI1145::read8(uint8_t reg) {
  uint8_t buffer[1] = {reg};
  i2c_dev->write_then_read(buffer, 1, buffer, 1);
  return buffer[0];
}

uint16_t Adafruit_SI1145::read16(uint8_t a) {
  uint8_t buffer[2] = {a, 0};
  i2c_dev->write_then_read(buffer, 1, buffer, 2);
  return ((uint16_t)buffer[0]) | ((uint16_t)buffer[1] << 8);
}

void Adafruit_SI1145::write8(uint8_t reg, uint8_t val) {
  uint8_t buffer[2] = {reg, val};
  i2c_dev->write(buffer, 2);
}