#include "APDS9960.h"

/**
* @brief Constructor - Instantiates APDS9960 object
*/
APDS9960::APDS9960()
{
	gesture_ud_delta_ = 0;
	gesture_lr_delta_ = 0;
	
	gesture_ud_count_ = 0;
	gesture_lr_count_ = 0;
	
	gesture_near_count_ = 0;
	gesture_far_count_ = 0;
	
	gesture_state_ = 0;
	gesture_motion_ = DIR_NONE;
}

/**
* @brief Destructor
*/
APDS9960::~APDS9960()
{

}

/**
* @brief Configures I2C communications and initializes registers to defaults
*
* @return True if initialized successfully. False otherwise.
*/
bool APDS9960::init()
{
	uint8_t id;

	/* Initialize I2C */
	fd_ = wiringPiI2CSetup(APDS9960_I2C_ADDR);
	if(fd_ == -1) {
		return false;
	}
	
	/* Read ID register and check against known values for APDS-9960 */
	if( !wireReadDataByte(APDS9960_ID, id) ) {
		return false;
	}
	if( !(id == APDS9960_ID_1 || id == APDS9960_ID_2) ) {
		return false;
	}
	
	/* Set ENABLE register to 0 (disable all features) */
	if( !setMode(ALL, OFF) ) {
		return false;
	}
	
	/* Set default values for ambient light and proximity registers */
	if( !wireWriteDataByte(APDS9960_ATIME, DEFAULT_ATIME) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_WTIME, DEFAULT_WTIME) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_PPULSE, DEFAULT_PROX_PPULSE) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_POFFSET_UR, DEFAULT_POFFSET_UR) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_POFFSET_DL, DEFAULT_POFFSET_DL) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_CONFIG1, DEFAULT_CONFIG1) ) {
		return false;
	}
	if( !setLEDDrive(DEFAULT_LDRIVE) ) {
		return false;
	}
	if( !setProximityGain(DEFAULT_PGAIN) ) {
		return false;
	}
	if( !setAmbientLightGain(DEFAULT_AGAIN) ) {
		return false;
	}
	if( !setProxIntLowThresh(DEFAULT_PILT) ) {
		return false;
	}
	if( !setProxIntHighThresh(DEFAULT_PIHT) ) {
		return false;
	}
	if( !setLightIntLowThreshold(DEFAULT_AILT) ) {
		return false;
	}
	if( !setLightIntHighThreshold(DEFAULT_AIHT) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_PERS, DEFAULT_PERS) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_CONFIG2, DEFAULT_CONFIG2) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_CONFIG3, DEFAULT_CONFIG3) ) {
		return false;
	}
	
	/* Set default values for gesture sense registers */
	if( !setGestureEnterThresh(DEFAULT_GPENTH) ) {
		return false;
	}
	if( !setGestureExitThresh(DEFAULT_GEXTH) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GCONF1, DEFAULT_GCONF1) ) {
		return false;
	}
	if( !setGestureGain(DEFAULT_GGAIN) ) {
		return false;
	}
	if( !setGestureLEDDrive(DEFAULT_GLDRIVE) ) {
		return false;
	}
	if( !setGestureWaitTime(DEFAULT_GWTIME) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GOFFSET_U, DEFAULT_GOFFSET) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GOFFSET_D, DEFAULT_GOFFSET) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GOFFSET_L, DEFAULT_GOFFSET) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GOFFSET_R, DEFAULT_GOFFSET) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GPULSE, DEFAULT_GPULSE) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_GCONF3, DEFAULT_GCONF3) ) {
		return false;
	}
	if( !setGestureIntEnable(DEFAULT_GIEN) ) {
		return false;
	}
	
#if 0
	/* Gesture config register dump */
	uint8_t reg;
	uint8_t val;

	for(reg = 0x80; reg <= 0xAF; reg++) {
		if( (reg != 0x82) && \
				(reg != 0x8A) && \
				(reg != 0x91) && \
				(reg != 0xA8) && \
				(reg != 0xAC) && \
				(reg != 0xAD) )
		{
			wireReadDataByte(reg, val);
			Serial.print(reg, HEX);
			Serial.print(": 0x");
			Serial.println(val, HEX);
		}
	}

	for(reg = 0xE4; reg <= 0xE7; reg++) {
		wireReadDataByte(reg, val);
		Serial.print(reg, HEX);
		Serial.print(": 0x");
		Serial.println(val, HEX);
	}
#endif

	return true;
}

/*******************************************************************************
* Public methods for controlling the APDS-9960
******************************************************************************/

/**
* @brief Reads and returns the contents of the ENABLE register
*
* @return Contents of the ENABLE register. 0xFF if error.
*/
uint8_t APDS9960::getMode()
{
	uint8_t enable_value;
	
	/* Read current ENABLE register */
	if( !wireReadDataByte(APDS9960_ENABLE, enable_value) ) {
		return ERROR;
	}
	
	return enable_value;
}

/**
* @brief Enables or disables a feature in the APDS-9960
*
* @param[in] mode which feature to enable
* @param[in] enable ON (1) or OFF (0)
* @return True if operation success. False otherwise.
*/
bool APDS9960::setMode(uint8_t mode, uint8_t enable)
{
	uint8_t reg_val;

	/* Read current ENABLE register */
	reg_val = getMode();
	if( reg_val == ERROR ) {
		return false;
	}
	
	/* Change bit(s) in ENABLE register */
	enable = enable & 0x01;
	if( mode >= 0 && mode <= 6 ) {
		if (enable) {
			reg_val |= (1 << mode);
		} else {
			reg_val &= ~(1 << mode);
		}
	} else if( mode == ALL ) {
		if (enable) {
			reg_val = 0x7F;
		} else {
			reg_val = 0x00;
		}
	}
	
	/* Write value back to ENABLE register */
	if( !wireWriteDataByte(APDS9960_ENABLE, reg_val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Starts the light (R/G/B/Ambient) sensor on the APDS-9960
*
* @param[in] interrupts true to enable hardware interrupt on high or low light
* @return True if sensor enabled correctly. False on error.
*/
bool APDS9960::enableLightSensor(bool interrupts)
{
	
	/* Set default gain, interrupts, enable power, and enable sensor */
	if( !setAmbientLightGain(DEFAULT_AGAIN) ) {
		return false;
	}
	if( interrupts ) {
		if( !setAmbientLightIntEnable(1) ) {
			return false;
		}
	} else {
		if( !setAmbientLightIntEnable(0) ) {
			return false;
		}
	}
	if( !enablePower() ){
		return false;
	}
	if( !setMode(AMBIENT_LIGHT, 1) ) {
		return false;
	}
	
	return true;

}

/**
* @brief Ends the light sensor on the APDS-9960
*
* @return True if sensor disabled correctly. False on error.
*/
bool APDS9960::disableLightSensor()
{
	if( !setAmbientLightIntEnable(0) ) {
		return false;
	}
	if( !setMode(AMBIENT_LIGHT, 0) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Starts the proximity sensor on the APDS-9960
*
* @param[in] interrupts true to enable hardware external interrupt on proximity
* @return True if sensor enabled correctly. False on error.
*/
bool APDS9960::enableProximitySensor(bool interrupts)
{
	/* Set default gain, LED, interrupts, enable power, and enable sensor */
	if( !setProximityGain(DEFAULT_PGAIN) ) {
		return false;
	}
	if( !setLEDDrive(DEFAULT_LDRIVE) ) {
		return false;
	}
	if( interrupts ) {
		if( !setProximityIntEnable(1) ) {
			return false;
		}
	} else {
		if( !setProximityIntEnable(0) ) {
			return false;
		}
	}
	if( !enablePower() ){
		return false;
	}
	if( !setMode(PROXIMITY, 1) ) {
		return false;
	}
	
	return true;
}
bool disableProximitySensor();

/**
* @brief Starts the gesture recognition engine on the APDS-9960
*
* @param[in] interrupts true to enable hardware external interrupt on gesture
* @return True if engine enabled correctly. False on error.
*/
bool APDS9960::enableGestureSensor(bool interrupts)
{
	
	/* Enable gesture mode
	Set ENABLE to 0 (power off)
	Set WTIME to 0xFF
	Set AUX to LED_BOOST_300
	Enable PON, WEN, PEN, GEN in ENABLE 
	*/
	resetGestureParameters();
	if( !wireWriteDataByte(APDS9960_WTIME, 0xFF) ) {
		return false;
	}
	if( !wireWriteDataByte(APDS9960_PPULSE, DEFAULT_GESTURE_PPULSE) ) {
		return false;
	}
	if( !setLEDBoost(LED_BOOST_100) ) {
		return false;
	}
	if( interrupts ) {
		if( !setGestureIntEnable(1) ) {
			return false;
		}
	} else {
		if( !setGestureIntEnable(0) ) {
			return false;
		}
	}
	if( !setGestureMode(1) ) {
		return false;
	}
	if( !enablePower() ){
		return false;
	}
	if( !setMode(WAIT, 1) ) {
		return false;
	}
	if( !setMode(PROXIMITY, 1) ) {
		return false;
	}
	if( !setMode(GESTURE, 1) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Ends the gesture recognition engine on the APDS-9960
*
* @return True if engine disabled correctly. False on error.
*/
bool APDS9960::disableGestureSensor()
{
	resetGestureParameters();
	if( !setGestureIntEnable(0) ) {
		return false;
	}
	if( !setGestureMode(0) ) {
		return false;
	}
	if( !setMode(GESTURE, 0) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Determines if there is a gesture available for reading
*
* @return True if gesture available. False otherwise.
*/
bool APDS9960::isGestureAvailable()
{
	uint8_t val;
	
	/* Read value from GSTATUS register */
	if( !wireReadDataByte(APDS9960_GSTATUS, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out GVALID bit */
	val &= APDS9960_GVALID;
	
	/* Return true/false based on GVALID bit */
	if( val == 1) {
		return true;
	} else {
		return false;
	}
}

/**
* @brief Processes a gesture event and returns best guessed gesture
*
* @return Number corresponding to gesture. -1 on error.
*/
int APDS9960::readGesture()
{
	uint8_t fifo_level = 0;
	uint8_t bytes_read = 0;
	uint8_t fifo_data[128];
	uint8_t gstatus;
	int motion;
	int i;
	
	/* Make sure that power and gesture is on and data is valid */
	if( !isGestureAvailable() || !(getMode() & 0b01000001) ) {
		return DIR_NONE;
	}
	
	/* Keep looping as long as gesture data is valid */
	while(1) {
		/* Wait some time to collect next batch of FIFO data */
		delay(FIFO_PAUSE_TIME);
		
		/* Get the contents of the STATUS register. Is data still valid? */
		if( !wireReadDataByte(APDS9960_GSTATUS, gstatus) ) {
			return ERROR;
		}
		
		/* If we have valid data, read in FIFO */
		if( (gstatus & APDS9960_GVALID) == APDS9960_GVALID ) {        

			/* Read the current FIFO level */
			if( !wireReadDataByte(APDS9960_GFLVL, fifo_level) ) {
				return ERROR;
			}

#if DEBUG
			Serial.print("FIFO Level: ");
			Serial.println(fifo_level);
#endif

			/* If there's stuff in the FIFO, read it into our data block */
			if( fifo_level > 0) {
				bytes_read = wireReadDataBlock(  APDS9960_GFIFO_U, 
				(uint8_t*)fifo_data, 
				(fifo_level * 4) );
				if( bytes_read == -1 ) {
					return ERROR;
				}
#if DEBUG
				Serial.print("FIFO Dump: ");
				for ( i = 0; i < bytes_read; i++ ) {
					Serial.print(fifo_data[i]);
					Serial.print(" ");
				}
				Serial.println();
#endif

				/* If at least 1 set of data, sort the data into U/D/L/R */
				if( bytes_read >= 4 ) {
					for( i = 0; i < bytes_read; i += 4 ) {
						gesture_data_.u_data[gesture_data_.index] = \
						fifo_data[i + 0];
						gesture_data_.d_data[gesture_data_.index] = \
						fifo_data[i + 1];
						gesture_data_.l_data[gesture_data_.index] = \
						fifo_data[i + 2];
						gesture_data_.r_data[gesture_data_.index] = \
						fifo_data[i + 3];
						gesture_data_.index++;
						gesture_data_.total_gestures++;
					}
					
#if DEBUG
					Serial.print("Up Data: ");
					for ( i = 0; i < gesture_data_.total_gestures; i++ ) {
						Serial.print(gesture_data_.u_data[i]);
						Serial.print(" ");
					}
					Serial.println();
#endif

					/* Filter and process gesture data. Decode near/far state */
					if( processGestureData() ) {
						if( decodeGesture() ) {
							//***TODO: U-Turn Gestures
#if DEBUG
							//Serial.println(gesture_motion_);
#endif
						}
					}
					
					/* Reset data */
					gesture_data_.index = 0;
					gesture_data_.total_gestures = 0;
				}
			}
		} else {
			
			/* Determine best guessed gesture and clean up */
			delay(FIFO_PAUSE_TIME);
			decodeGesture();
			motion = gesture_motion_;
#if DEBUG
			Serial.print("END: ");
			Serial.println(gesture_motion_);
#endif
			resetGestureParameters();
			return motion;
		}
	}
}

/**
* Turn the APDS-9960 on
*
* @return True if operation successful. False otherwise.
*/
bool APDS9960::enablePower()
{
	if( !setMode(POWER, 1) ) {
		return false;
	}
	
	return true;
}

/**
* Turn the APDS-9960 off
*
* @return True if operation successful. False otherwise.
*/
bool APDS9960::disablePower()
{
	if( !setMode(POWER, 0) ) {
		return false;
	}
	
	return true;
}

/*******************************************************************************
* Ambient light and color sensor controls
******************************************************************************/

/**
* @brief Reads the ambient (clear) light level as a 16-bit value
*
* @param[out] val value of the light sensor.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::readAmbientLight(uint16_t &val)
{
	uint8_t val_byte;
	val = 0;
	
	/* Read value from clear channel, low byte register */
	if( !wireReadDataByte(APDS9960_CDATAL, val_byte) ) {
		return false;
	}
	val = val_byte;
	
	/* Read value from clear channel, high byte register */
	if( !wireReadDataByte(APDS9960_CDATAH, val_byte) ) {
		return false;
	}
	val = val + ((uint16_t)val_byte << 8);
	
	return true;
}

/**
* @brief Reads the red light level as a 16-bit value
*
* @param[out] val value of the light sensor.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::readRedLight(uint16_t &val)
{
	uint8_t val_byte;
	val = 0;
	
	/* Read value from clear channel, low byte register */
	if( !wireReadDataByte(APDS9960_RDATAL, val_byte) ) {
		return false;
	}
	val = val_byte;
	
	/* Read value from clear channel, high byte register */
	if( !wireReadDataByte(APDS9960_RDATAH, val_byte) ) {
		return false;
	}
	val = val + ((uint16_t)val_byte << 8);
	
	return true;
}

/**
* @brief Reads the green light level as a 16-bit value
*
* @param[out] val value of the light sensor.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::readGreenLight(uint16_t &val)
{
	uint8_t val_byte;
	val = 0;
	
	/* Read value from clear channel, low byte register */
	if( !wireReadDataByte(APDS9960_GDATAL, val_byte) ) {
		return false;
	}
	val = val_byte;
	
	/* Read value from clear channel, high byte register */
	if( !wireReadDataByte(APDS9960_GDATAH, val_byte) ) {
		return false;
	}
	val = val + ((uint16_t)val_byte << 8);
	
	return true;
}

/**
* @brief Reads the red light level as a 16-bit value
*
* @param[out] val value of the light sensor.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::readBlueLight(uint16_t &val)
{
	uint8_t val_byte;
	val = 0;
	
	/* Read value from clear channel, low byte register */
	if( !wireReadDataByte(APDS9960_BDATAL, val_byte) ) {
		return false;
	}
	val = val_byte;
	
	/* Read value from clear channel, high byte register */
	if( !wireReadDataByte(APDS9960_BDATAH, val_byte) ) {
		return false;
	}
	val = val + ((uint16_t)val_byte << 8);
	
	return true;
}

/*******************************************************************************
* Proximity sensor controls
******************************************************************************/

/**
* @brief Reads the proximity level as an 8-bit value
*
* @param[out] val value of the proximity sensor.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::readProximity(uint8_t &val)
{
	val = 0;
	
	/* Read value from proximity data register */
	if( !wireReadDataByte(APDS9960_PDATA, val) ) {
		return false;
	}
	
	return true;
}

/*******************************************************************************
* High-level gesture controls
******************************************************************************/

/**
* @brief Resets all the parameters in the gesture data member
*/
void APDS9960::resetGestureParameters()
{
	gesture_data_.index = 0;
	gesture_data_.total_gestures = 0;
	
	gesture_ud_delta_ = 0;
	gesture_lr_delta_ = 0;
	
	gesture_ud_count_ = 0;
	gesture_lr_count_ = 0;
	
	gesture_near_count_ = 0;
	gesture_far_count_ = 0;
	
	gesture_state_ = 0;
	gesture_motion_ = DIR_NONE;
}

/**
* @brief Processes the raw gesture data to determine swipe direction
*
* @return True if near or far state seen. False otherwise.
*/
bool APDS9960::processGestureData()
{
	uint8_t u_first = 0;
	uint8_t d_first = 0;
	uint8_t l_first = 0;
	uint8_t r_first = 0;
	uint8_t u_last = 0;
	uint8_t d_last = 0;
	uint8_t l_last = 0;
	uint8_t r_last = 0;
	int ud_ratio_first;
	int lr_ratio_first;
	int ud_ratio_last;
	int lr_ratio_last;
	int ud_delta;
	int lr_delta;
	int i;

	/* If we have less than 4 total gestures, that's not enough */
	if( gesture_data_.total_gestures <= 4 ) {
		return false;
	}
	
	/* Check to make sure our data isn't out of bounds */
	if( (gesture_data_.total_gestures <= 32) && \
			(gesture_data_.total_gestures > 0) ) {
		
		/* Find the first value in U/D/L/R above the threshold */
		for( i = 0; i < gesture_data_.total_gestures; i++ ) {
			if( (gesture_data_.u_data[i] > GESTURE_THRESHOLD_OUT) &&
					(gesture_data_.d_data[i] > GESTURE_THRESHOLD_OUT) &&
					(gesture_data_.l_data[i] > GESTURE_THRESHOLD_OUT) &&
					(gesture_data_.r_data[i] > GESTURE_THRESHOLD_OUT) ) {
				
				u_first = gesture_data_.u_data[i];
				d_first = gesture_data_.d_data[i];
				l_first = gesture_data_.l_data[i];
				r_first = gesture_data_.r_data[i];
				break;
			}
		}
		
		/* If one of the _first values is 0, then there is no good data */
		if( (u_first == 0) || (d_first == 0) || \
				(l_first == 0) || (r_first == 0) ) {
			
			return false;
		}
		/* Find the last value in U/D/L/R above the threshold */
		for( i = gesture_data_.total_gestures - 1; i >= 0; i-- ) {
#if DEBUG
			Serial.print(F("Finding last: "));
			Serial.print(F("U:"));
			Serial.print(gesture_data_.u_data[i]);
			Serial.print(F(" D:"));
			Serial.print(gesture_data_.d_data[i]);
			Serial.print(F(" L:"));
			Serial.print(gesture_data_.l_data[i]);
			Serial.print(F(" R:"));
			Serial.println(gesture_data_.r_data[i]);
#endif
			if( (gesture_data_.u_data[i] > GESTURE_THRESHOLD_OUT) &&
					(gesture_data_.d_data[i] > GESTURE_THRESHOLD_OUT) &&
					(gesture_data_.l_data[i] > GESTURE_THRESHOLD_OUT) &&
					(gesture_data_.r_data[i] > GESTURE_THRESHOLD_OUT) ) {
				
				u_last = gesture_data_.u_data[i];
				d_last = gesture_data_.d_data[i];
				l_last = gesture_data_.l_data[i];
				r_last = gesture_data_.r_data[i];
				break;
			}
		}
	}
	
	/* Calculate the first vs. last ratio of up/down and left/right */
	ud_ratio_first = ((u_first - d_first) * 100) / (u_first + d_first);
	lr_ratio_first = ((l_first - r_first) * 100) / (l_first + r_first);
	ud_ratio_last = ((u_last - d_last) * 100) / (u_last + d_last);
	lr_ratio_last = ((l_last - r_last) * 100) / (l_last + r_last);
	
#if DEBUG
	Serial.print(F("Last Values: "));
	Serial.print(F("U:"));
	Serial.print(u_last);
	Serial.print(F(" D:"));
	Serial.print(d_last);
	Serial.print(F(" L:"));
	Serial.print(l_last);
	Serial.print(F(" R:"));
	Serial.println(r_last);

	Serial.print(F("Ratios: "));
	Serial.print(F("UD Fi: "));
	Serial.print(ud_ratio_first);
	Serial.print(F(" UD La: "));
	Serial.print(ud_ratio_last);
	Serial.print(F(" LR Fi: "));
	Serial.print(lr_ratio_first);
	Serial.print(F(" LR La: "));
	Serial.println(lr_ratio_last);
#endif
	
	/* Determine the difference between the first and last ratios */
	ud_delta = ud_ratio_last - ud_ratio_first;
	lr_delta = lr_ratio_last - lr_ratio_first;
	
#if DEBUG
	Serial.print("Deltas: ");
	Serial.print("UD: ");
	Serial.print(ud_delta);
	Serial.print(" LR: ");
	Serial.println(lr_delta);
#endif

	/* Accumulate the UD and LR delta values */
	gesture_ud_delta_ += ud_delta;
	gesture_lr_delta_ += lr_delta;
	
#if DEBUG
	Serial.print("Accumulations: ");
	Serial.print("UD: ");
	Serial.print(gesture_ud_delta_);
	Serial.print(" LR: ");
	Serial.println(gesture_lr_delta_);
#endif
	
	/* Determine U/D gesture */
	if( gesture_ud_delta_ >= GESTURE_SENSITIVITY_1 ) {
		gesture_ud_count_ = 1;
	} else if( gesture_ud_delta_ <= -GESTURE_SENSITIVITY_1 ) {
		gesture_ud_count_ = -1;
	} else {
		gesture_ud_count_ = 0;
	}
	
	/* Determine L/R gesture */
	if( gesture_lr_delta_ >= GESTURE_SENSITIVITY_1 ) {
		gesture_lr_count_ = 1;
	} else if( gesture_lr_delta_ <= -GESTURE_SENSITIVITY_1 ) {
		gesture_lr_count_ = -1;
	} else {
		gesture_lr_count_ = 0;
	}
	
	/* Determine Near/Far gesture */
	if( (gesture_ud_count_ == 0) && (gesture_lr_count_ == 0) ) {
		if( (abs(ud_delta) < GESTURE_SENSITIVITY_2) && \
				(abs(lr_delta) < GESTURE_SENSITIVITY_2) ) {
			
			if( (ud_delta == 0) && (lr_delta == 0) ) {
				gesture_near_count_++;
			} else if( (ud_delta != 0) || (lr_delta != 0) ) {
				gesture_far_count_++;
			}
			
			if( (gesture_near_count_ >= 10) && (gesture_far_count_ >= 2) ) {
				if( (ud_delta == 0) && (lr_delta == 0) ) {
					gesture_state_ = NEAR_STATE;
				} else if( (ud_delta != 0) && (lr_delta != 0) ) {
					gesture_state_ = FAR_STATE;
				}
				return true;
			}
		}
	} else {
		if( (abs(ud_delta) < GESTURE_SENSITIVITY_2) && \
				(abs(lr_delta) < GESTURE_SENSITIVITY_2) ) {
			
			if( (ud_delta == 0) && (lr_delta == 0) ) {
				gesture_near_count_++;
			}
			
			if( gesture_near_count_ >= 10 ) {
				gesture_ud_count_ = 0;
				gesture_lr_count_ = 0;
				gesture_ud_delta_ = 0;
				gesture_lr_delta_ = 0;
			}
		}
	}
	
#if DEBUG
	Serial.print("UD_CT: ");
	Serial.print(gesture_ud_count_);
	Serial.print(" LR_CT: ");
	Serial.print(gesture_lr_count_);
	Serial.print(" NEAR_CT: ");
	Serial.print(gesture_near_count_);
	Serial.print(" FAR_CT: ");
	Serial.println(gesture_far_count_);
	Serial.println("----------");
#endif
	
	return false;
}

/**
* @brief Determines swipe direction or near/far state
*
* @return True if near/far event. False otherwise.
*/
bool APDS9960::decodeGesture()
{
	/* Return if near or far event is detected */
	if( gesture_state_ == NEAR_STATE ) {
		gesture_motion_ = DIR_NEAR;
		return true;
	} else if ( gesture_state_ == FAR_STATE ) {
		gesture_motion_ = DIR_FAR;
		return true;
	}
	
	/* Determine swipe direction */
	if( (gesture_ud_count_ == -1) && (gesture_lr_count_ == 0) ) {
		gesture_motion_ = DIR_UP;
	} else if( (gesture_ud_count_ == 1) && (gesture_lr_count_ == 0) ) {
		gesture_motion_ = DIR_DOWN;
	} else if( (gesture_ud_count_ == 0) && (gesture_lr_count_ == 1) ) {
		gesture_motion_ = DIR_RIGHT;
	} else if( (gesture_ud_count_ == 0) && (gesture_lr_count_ == -1) ) {
		gesture_motion_ = DIR_LEFT;
	} else if( (gesture_ud_count_ == -1) && (gesture_lr_count_ == 1) ) {
		if( abs(gesture_ud_delta_) > abs(gesture_lr_delta_) ) {
			gesture_motion_ = DIR_UP;
		} else {
			gesture_motion_ = DIR_RIGHT;
		}
	} else if( (gesture_ud_count_ == 1) && (gesture_lr_count_ == -1) ) {
		if( abs(gesture_ud_delta_) > abs(gesture_lr_delta_) ) {
			gesture_motion_ = DIR_DOWN;
		} else {
			gesture_motion_ = DIR_LEFT;
		}
	} else if( (gesture_ud_count_ == -1) && (gesture_lr_count_ == -1) ) {
		if( abs(gesture_ud_delta_) > abs(gesture_lr_delta_) ) {
			gesture_motion_ = DIR_UP;
		} else {
			gesture_motion_ = DIR_LEFT;
		}
	} else if( (gesture_ud_count_ == 1) && (gesture_lr_count_ == 1) ) {
		if( abs(gesture_ud_delta_) > abs(gesture_lr_delta_) ) {
			gesture_motion_ = DIR_DOWN;
		} else {
			gesture_motion_ = DIR_RIGHT;
		}
	} else {
		return false;
	}
	
	return true;
}

/*******************************************************************************
* Getters and setters for register values
******************************************************************************/

/**
* @brief Returns the lower threshold for proximity detection
*
* @return lower threshold
*/
uint8_t APDS9960::getProxIntLowThresh()
{
	uint8_t val;
	
	/* Read value from PILT register */
	if( !wireReadDataByte(APDS9960_PILT, val) ) {
		val = 0;
	}
	
	return val;
}

/**
* @brief Sets the lower threshold for proximity detection
*
* @param[in] threshold the lower proximity threshold
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProxIntLowThresh(uint8_t threshold)
{
	if( !wireWriteDataByte(APDS9960_PILT, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Returns the high threshold for proximity detection
*
* @return high threshold
*/
uint8_t APDS9960::getProxIntHighThresh()
{
	uint8_t val;
	
	/* Read value from PIHT register */
	if( !wireReadDataByte(APDS9960_PIHT, val) ) {
		val = 0;
	}
	
	return val;
}

/**
* @brief Sets the high threshold for proximity detection
*
* @param[in] threshold the high proximity threshold
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProxIntHighThresh(uint8_t threshold)
{
	if( !wireWriteDataByte(APDS9960_PIHT, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Returns LED drive strength for proximity and ALS
*
* Value    LED Current
*   0        100 mA
*   1         50 mA
*   2         25 mA
*   3         12.5 mA
*
* @return the value of the LED drive strength. 0xFF on failure.
*/
uint8_t APDS9960::getLEDDrive()
{
	uint8_t val;
	
	/* Read value from CONTROL register */
	if( !wireReadDataByte(APDS9960_CONTROL, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out LED drive bits */
	val = (val >> 6) & 0b00000011;
	
	return val;
}

/**
* @brief Sets the LED drive strength for proximity and ALS
*
* Value    LED Current
*   0        100 mA
*   1         50 mA
*   2         25 mA
*   3         12.5 mA
*
* @param[in] drive the value (0-3) for the LED drive strength
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setLEDDrive(uint8_t drive)
{
	uint8_t val;
	
	/* Read value from CONTROL register */
	if( !wireReadDataByte(APDS9960_CONTROL, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	drive &= 0b00000011;
	drive = drive << 6;
	val &= 0b00111111;
	val |= drive;
	
	/* Write register value back into CONTROL register */
	if( !wireWriteDataByte(APDS9960_CONTROL, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Returns receiver gain for proximity detection
*
* Value    Gain
*   0       1x
*   1       2x
*   2       4x
*   3       8x
*
* @return the value of the proximity gain. 0xFF on failure.
*/
uint8_t APDS9960::getProximityGain()
{
	uint8_t val;
	
	/* Read value from CONTROL register */
	if( !wireReadDataByte(APDS9960_CONTROL, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out PDRIVE bits */
	val = (val >> 2) & 0b00000011;
	
	return val;
}

/**
* @brief Sets the receiver gain for proximity detection
*
* Value    Gain
*   0       1x
*   1       2x
*   2       4x
*   3       8x
*
* @param[in] drive the value (0-3) for the gain
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProximityGain(uint8_t drive)
{
	uint8_t val;
	
	/* Read value from CONTROL register */
	if( !wireReadDataByte(APDS9960_CONTROL, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	drive &= 0b00000011;
	drive = drive << 2;
	val &= 0b11110011;
	val |= drive;
	
	/* Write register value back into CONTROL register */
	if( !wireWriteDataByte(APDS9960_CONTROL, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Returns receiver gain for the ambient light sensor (ALS)
*
* Value    Gain
*   0        1x
*   1        4x
*   2       16x
*   3       64x
*
* @return the value of the ALS gain. 0xFF on failure.
*/
uint8_t APDS9960::getAmbientLightGain()
{
	uint8_t val;
	
	/* Read value from CONTROL register */
	if( !wireReadDataByte(APDS9960_CONTROL, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out ADRIVE bits */
	val &= 0b00000011;
	
	return val;
}

/**
* @brief Sets the receiver gain for the ambient light sensor (ALS)
*
* Value    Gain
*   0        1x
*   1        4x
*   2       16x
*   3       64x
*
* @param[in] drive the value (0-3) for the gain
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setAmbientLightGain(uint8_t drive)
{
	uint8_t val;
	
	/* Read value from CONTROL register */
	if( !wireReadDataByte(APDS9960_CONTROL, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	drive &= 0b00000011;
	val &= 0b11111100;
	val |= drive;
	
	/* Write register value back into CONTROL register */
	if( !wireWriteDataByte(APDS9960_CONTROL, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Get the current LED boost value
* 
* Value  Boost Current
*   0        100%
*   1        150%
*   2        200%
*   3        300%
*
* @return The LED boost value. 0xFF on failure.
*/
uint8_t APDS9960::getLEDBoost()
{
	uint8_t val;
	
	/* Read value from CONFIG2 register */
	if( !wireReadDataByte(APDS9960_CONFIG2, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out LED_BOOST bits */
	val = (val >> 4) & 0b00000011;
	
	return val;
}

/**
* @brief Sets the LED current boost value
*
* Value  Boost Current
*   0        100%
*   1        150%
*   2        200%
*   3        300%
*
* @param[in] drive the value (0-3) for current boost (100-300%)
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setLEDBoost(uint8_t boost)
{
	uint8_t val;
	
	/* Read value from CONFIG2 register */
	if( !wireReadDataByte(APDS9960_CONFIG2, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	boost &= 0b00000011;
	boost = boost << 4;
	val &= 0b11001111;
	val |= boost;
	
	/* Write register value back into CONFIG2 register */
	if( !wireWriteDataByte(APDS9960_CONFIG2, val) ) {
		return false;
	}
	
	return true;
}    

/**
* @brief Gets proximity gain compensation enable
*
* @return 1 if compensation is enabled. 0 if not. 0xFF on error.
*/
uint8_t APDS9960::getProxGainCompEnable()
{
	uint8_t val;
	
	/* Read value from CONFIG3 register */
	if( !wireReadDataByte(APDS9960_CONFIG3, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out PCMP bits */
	val = (val >> 5) & 0b00000001;
	
	return val;
}

/**
* @brief Sets the proximity gain compensation enable
*
* @param[in] enable 1 to enable compensation. 0 to disable compensation.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProxGainCompEnable(uint8_t enable)
{
	uint8_t val;
	
	/* Read value from CONFIG3 register */
	if( !wireReadDataByte(APDS9960_CONFIG3, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	enable &= 0b00000001;
	enable = enable << 5;
	val &= 0b11011111;
	val |= enable;
	
	/* Write register value back into CONFIG3 register */
	if( !wireWriteDataByte(APDS9960_CONFIG3, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the current mask for enabled/disabled proximity photodiodes
*
* 1 = disabled, 0 = enabled
* Bit    Photodiode
*  3       UP
*  2       DOWN
*  1       LEFT
*  0       RIGHT
*
* @return Current proximity mask for photodiodes. 0xFF on error.
*/
uint8_t APDS9960::getProxPhotoMask()
{
	uint8_t val;
	
	/* Read value from CONFIG3 register */
	if( !wireReadDataByte(APDS9960_CONFIG3, val) ) {
		return ERROR;
	}
	
	/* Mask out photodiode enable mask bits */
	val &= 0b00001111;
	
	return val;
}

/**
* @brief Sets the mask for enabling/disabling proximity photodiodes
*
* 1 = disabled, 0 = enabled
* Bit    Photodiode
*  3       UP
*  2       DOWN
*  1       LEFT
*  0       RIGHT
*
* @param[in] mask 4-bit mask value
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProxPhotoMask(uint8_t mask)
{
	uint8_t val;
	
	/* Read value from CONFIG3 register */
	if( !wireReadDataByte(APDS9960_CONFIG3, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	mask &= 0b00001111;
	val &= 0b11110000;
	val |= mask;
	
	/* Write register value back into CONFIG3 register */
	if( !wireWriteDataByte(APDS9960_CONFIG3, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the entry proximity threshold for gesture sensing
*
* @return Current entry proximity threshold.
*/
uint8_t APDS9960::getGestureEnterThresh()
{
	uint8_t val;
	
	/* Read value from GPENTH register */
	if( !wireReadDataByte(APDS9960_GPENTH, val) ) {
		val = 0;
	}
	
	return val;
}

/**
* @brief Sets the entry proximity threshold for gesture sensing
*
* @param[in] threshold proximity value needed to start gesture mode
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureEnterThresh(uint8_t threshold)
{
	if( !wireWriteDataByte(APDS9960_GPENTH, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the exit proximity threshold for gesture sensing
*
* @return Current exit proximity threshold.
*/
uint8_t APDS9960::getGestureExitThresh()
{
	uint8_t val;
	
	/* Read value from GEXTH register */
	if( !wireReadDataByte(APDS9960_GEXTH, val) ) {
		val = 0;
	}
	
	return val;
}

/**
* @brief Sets the exit proximity threshold for gesture sensing
*
* @param[in] threshold proximity value needed to end gesture mode
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureExitThresh(uint8_t threshold)
{
	if( !wireWriteDataByte(APDS9960_GEXTH, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the gain of the photodiode during gesture mode
*
* Value    Gain
*   0       1x
*   1       2x
*   2       4x
*   3       8x
*
* @return the current photodiode gain. 0xFF on error.
*/
uint8_t APDS9960::getGestureGain()
{
	uint8_t val;
	
	/* Read value from GCONF2 register */
	if( !wireReadDataByte(APDS9960_GCONF2, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out GGAIN bits */
	val = (val >> 5) & 0b00000011;
	
	return val;
}

/**
* @brief Sets the gain of the photodiode during gesture mode
*
* Value    Gain
*   0       1x
*   1       2x
*   2       4x
*   3       8x
*
* @param[in] gain the value for the photodiode gain
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureGain(uint8_t gain)
{
	uint8_t val;
	
	/* Read value from GCONF2 register */
	if( !wireReadDataByte(APDS9960_GCONF2, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	gain &= 0b00000011;
	gain = gain << 5;
	val &= 0b10011111;
	val |= gain;
	
	/* Write register value back into GCONF2 register */
	if( !wireWriteDataByte(APDS9960_GCONF2, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the drive current of the LED during gesture mode
*
* Value    LED Current
*   0        100 mA
*   1         50 mA
*   2         25 mA
*   3         12.5 mA
*
* @return the LED drive current value. 0xFF on error.
*/
uint8_t APDS9960::getGestureLEDDrive()
{
	uint8_t val;
	
	/* Read value from GCONF2 register */
	if( !wireReadDataByte(APDS9960_GCONF2, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out GLDRIVE bits */
	val = (val >> 3) & 0b00000011;
	
	return val;
}

/**
* @brief Sets the LED drive current during gesture mode
*
* Value    LED Current
*   0        100 mA
*   1         50 mA
*   2         25 mA
*   3         12.5 mA
*
* @param[in] drive the value for the LED drive current
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureLEDDrive(uint8_t drive)
{
	uint8_t val;
	
	/* Read value from GCONF2 register */
	if( !wireReadDataByte(APDS9960_GCONF2, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	drive &= 0b00000011;
	drive = drive << 3;
	val &= 0b11100111;
	val |= drive;
	
	/* Write register value back into GCONF2 register */
	if( !wireWriteDataByte(APDS9960_GCONF2, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the time in low power mode between gesture detections
*
* Value    Wait time
*   0          0 ms
*   1          2.8 ms
*   2          5.6 ms
*   3          8.4 ms
*   4         14.0 ms
*   5         22.4 ms
*   6         30.8 ms
*   7         39.2 ms
*
* @return the current wait time between gestures. 0xFF on error.
*/
uint8_t APDS9960::getGestureWaitTime()
{
	uint8_t val;
	
	/* Read value from GCONF2 register */
	if( !wireReadDataByte(APDS9960_GCONF2, val) ) {
		return ERROR;
	}
	
	/* Mask out GWTIME bits */
	val &= 0b00000111;
	
	return val;
}

/**
* @brief Sets the time in low power mode between gesture detections
*
* Value    Wait time
*   0          0 ms
*   1          2.8 ms
*   2          5.6 ms
*   3          8.4 ms
*   4         14.0 ms
*   5         22.4 ms
*   6         30.8 ms
*   7         39.2 ms
*
* @param[in] the value for the wait time
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureWaitTime(uint8_t time)
{
	uint8_t val;
	
	/* Read value from GCONF2 register */
	if( !wireReadDataByte(APDS9960_GCONF2, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	time &= 0b00000111;
	val &= 0b11111000;
	val |= time;
	
	/* Write register value back into GCONF2 register */
	if( !wireWriteDataByte(APDS9960_GCONF2, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the low threshold for ambient light interrupts
*
* @param[out] threshold current low threshold stored on the APDS-9960
* @return True if operation successful. False otherwise.
*/
bool APDS9960::getLightIntLowThreshold(uint16_t &threshold)
{
	uint8_t val_byte;
	threshold = 0;
	
	/* Read value from ambient light low threshold, low byte register */
	if( !wireReadDataByte(APDS9960_AILTL, val_byte) ) {
		return false;
	}
	threshold = val_byte;
	
	/* Read value from ambient light low threshold, high byte register */
	if( !wireReadDataByte(APDS9960_AILTH, val_byte) ) {
		return false;
	}
	threshold = threshold + ((uint16_t)val_byte << 8);
	
	return true;
}

/**
* @brief Sets the low threshold for ambient light interrupts
*
* @param[in] threshold low threshold value for interrupt to trigger
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setLightIntLowThreshold(uint16_t threshold)
{
	uint8_t val_low;
	uint8_t val_high;
	
	/* Break 16-bit threshold into 2 8-bit values */
	val_low = threshold & 0x00FF;
	val_high = (threshold & 0xFF00) >> 8;
	
	/* Write low byte */
	if( !wireWriteDataByte(APDS9960_AILTL, val_low) ) {
		return false;
	}
	
	/* Write high byte */
	if( !wireWriteDataByte(APDS9960_AILTH, val_high) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the high threshold for ambient light interrupts
*
* @param[out] threshold current low threshold stored on the APDS-9960
* @return True if operation successful. False otherwise.
*/
bool APDS9960::getLightIntHighThreshold(uint16_t &threshold)
{
	uint8_t val_byte;
	threshold = 0;
	
	/* Read value from ambient light high threshold, low byte register */
	if( !wireReadDataByte(APDS9960_AIHTL, val_byte) ) {
		return false;
	}
	threshold = val_byte;
	
	/* Read value from ambient light high threshold, high byte register */
	if( !wireReadDataByte(APDS9960_AIHTH, val_byte) ) {
		return false;
	}
	threshold = threshold + ((uint16_t)val_byte << 8);
	
	return true;
}

/**
* @brief Sets the high threshold for ambient light interrupts
*
* @param[in] threshold high threshold value for interrupt to trigger
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setLightIntHighThreshold(uint16_t threshold)
{
	uint8_t val_low;
	uint8_t val_high;
	
	/* Break 16-bit threshold into 2 8-bit values */
	val_low = threshold & 0x00FF;
	val_high = (threshold & 0xFF00) >> 8;
	
	/* Write low byte */
	if( !wireWriteDataByte(APDS9960_AIHTL, val_low) ) {
		return false;
	}
	
	/* Write high byte */
	if( !wireWriteDataByte(APDS9960_AIHTH, val_high) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the low threshold for proximity interrupts
*
* @param[out] threshold current low threshold stored on the APDS-9960
* @return True if operation successful. False otherwise.
*/
bool APDS9960::getProximityIntLowThreshold(uint8_t &threshold)
{
	threshold = 0;
	
	/* Read value from proximity low threshold register */
	if( !wireReadDataByte(APDS9960_PILT, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Sets the low threshold for proximity interrupts
*
* @param[in] threshold low threshold value for interrupt to trigger
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProximityIntLowThreshold(uint8_t threshold)
{
	
	/* Write threshold value to register */
	if( !wireWriteDataByte(APDS9960_PILT, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets the high threshold for proximity interrupts
*
* @param[out] threshold current low threshold stored on the APDS-9960
* @return True if operation successful. False otherwise.
*/
bool APDS9960::getProximityIntHighThreshold(uint8_t &threshold)
{
	threshold = 0;
	
	/* Read value from proximity low threshold register */
	if( !wireReadDataByte(APDS9960_PIHT, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Sets the high threshold for proximity interrupts
*
* @param[in] threshold high threshold value for interrupt to trigger
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProximityIntHighThreshold(uint8_t threshold)
{
	
	/* Write threshold value to register */
	if( !wireWriteDataByte(APDS9960_PIHT, threshold) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets if ambient light interrupts are enabled or not
*
* @return 1 if interrupts are enabled, 0 if not. 0xFF on error.
*/
uint8_t APDS9960::getAmbientLightIntEnable()
{
	uint8_t val;
	
	/* Read value from ENABLE register */
	if( !wireReadDataByte(APDS9960_ENABLE, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out AIEN bit */
	val = (val >> 4) & 0b00000001;
	
	return val;
}

/**
* @brief Turns ambient light interrupts on or off
*
* @param[in] enable 1 to enable interrupts, 0 to turn them off
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setAmbientLightIntEnable(uint8_t enable)
{
	uint8_t val;
	
	/* Read value from ENABLE register */
	if( !wireReadDataByte(APDS9960_ENABLE, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	enable &= 0b00000001;
	enable = enable << 4;
	val &= 0b11101111;
	val |= enable;
	
	/* Write register value back into ENABLE register */
	if( !wireWriteDataByte(APDS9960_ENABLE, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets if proximity interrupts are enabled or not
*
* @return 1 if interrupts are enabled, 0 if not. 0xFF on error.
*/
uint8_t APDS9960::getProximityIntEnable()
{
	uint8_t val;
	
	/* Read value from ENABLE register */
	if( !wireReadDataByte(APDS9960_ENABLE, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out PIEN bit */
	val = (val >> 5) & 0b00000001;
	
	return val;
}

/**
* @brief Turns proximity interrupts on or off
*
* @param[in] enable 1 to enable interrupts, 0 to turn them off
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setProximityIntEnable(uint8_t enable)
{
	uint8_t val;
	
	/* Read value from ENABLE register */
	if( !wireReadDataByte(APDS9960_ENABLE, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	enable &= 0b00000001;
	enable = enable << 5;
	val &= 0b11011111;
	val |= enable;
	
	/* Write register value back into ENABLE register */
	if( !wireWriteDataByte(APDS9960_ENABLE, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Gets if gesture interrupts are enabled or not
*
* @return 1 if interrupts are enabled, 0 if not. 0xFF on error.
*/
uint8_t APDS9960::getGestureIntEnable()
{
	uint8_t val;
	
	/* Read value from GCONF4 register */
	if( !wireReadDataByte(APDS9960_GCONF4, val) ) {
		return ERROR;
	}
	
	/* Shift and mask out GIEN bit */
	val = (val >> 1) & 0b00000001;
	
	return val;
}

/**
* @brief Turns gesture-related interrupts on or off
*
* @param[in] enable 1 to enable interrupts, 0 to turn them off
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureIntEnable(uint8_t enable)
{
	uint8_t val;
	
	/* Read value from GCONF4 register */
	if( !wireReadDataByte(APDS9960_GCONF4, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	enable &= 0b00000001;
	enable = enable << 1;
	val &= 0b11111101;
	val |= enable;
	
	/* Write register value back into GCONF4 register */
	if( !wireWriteDataByte(APDS9960_GCONF4, val) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Clears the ambient light interrupt
*
* @return True if operation completed successfully. False otherwise.
*/
bool APDS9960::clearAmbientLightInt()
{
	uint8_t throwaway;
	if( !wireReadDataByte(APDS9960_AICLEAR, throwaway) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Clears the proximity interrupt
*
* @return True if operation completed successfully. False otherwise.
*/
bool APDS9960::clearProximityInt()
{
	uint8_t throwaway;
	if( !wireReadDataByte(APDS9960_PICLEAR, throwaway) ) {
		return false;
	}
	
	return true;
}

/**
* @brief Tells if the gesture state machine is currently running
*
* @return 1 if gesture state machine is running, 0 if not. 0xFF on error.
*/
uint8_t APDS9960::getGestureMode()
{
	uint8_t val;
	
	/* Read value from GCONF4 register */
	if( !wireReadDataByte(APDS9960_GCONF4, val) ) {
		return ERROR;
	}
	
	/* Mask out GMODE bit */
	val &= 0b00000001;
	
	return val;
}

/**
* @brief Tells the state machine to either enter or exit gesture state machine
*
* @param[in] mode 1 to enter gesture state machine, 0 to exit.
* @return True if operation successful. False otherwise.
*/
bool APDS9960::setGestureMode(uint8_t mode)
{
	uint8_t val;
	
	/* Read value from GCONF4 register */
	if( !wireReadDataByte(APDS9960_GCONF4, val) ) {
		return false;
	}
	
	/* Set bits in register to given value */
	mode &= 0b00000001;
	val &= 0b11111110;
	val |= mode;
	
	/* Write register value back into GCONF4 register */
	if( !wireWriteDataByte(APDS9960_GCONF4, val) ) {
		return false;
	}
	
	return true;
}

/*******************************************************************************
* Raw I2C Reads and Writes
******************************************************************************/

/**
* @brief Writes a single byte to the I2C device (no register)
*
* @param[in] val the 1-byte value to write to the I2C device
* @return True if successful write operation. False otherwise.
*/
bool APDS9960::wireWriteByte(uint8_t val)
{    
	if(wiringPiI2CWrite(fd_, val) != 0) {
		return false;
	}
	return true;
}

/**
* @brief Writes a single byte to the I2C device and specified register
*
* @param[in] reg the register in the I2C device to write to
* @param[in] val the 1-byte value to write to the I2C device
* @return True if successful write operation. False otherwise.
*/
bool APDS9960::wireWriteDataByte(uint8_t reg, uint8_t val)
{
	if(wiringPiI2CWriteReg8(fd_, reg, val) != 0) {
		return false;
	}

	return true;
}

/**
* @brief Writes a block (array) of bytes to the I2C device and register
*
* @param[in] reg the register in the I2C device to write to
* @param[in] val pointer to the beginning of the data byte array
* @param[in] len the length (in bytes) of the data to write
* @return True if successful write operation. False otherwise.
*/
bool APDS9960::wireWriteDataBlock(  uint8_t reg, 
uint8_t *val, 
unsigned int len)
{
	if(wiringPiI2CWrite(fd_, reg) < 0) {
		return false;
	}

	unsigned char i = 0;
	for(i = 0; i < len; i++) {
		if(wiringPiI2CWrite(fd_, val[i]) < 0) {
			return false;
		}
	}
	return true;
}

/**
* @brief Reads a single byte from the I2C device and specified register
*
* @param[in] reg the register to read from
* @param[out] the value returned from the register
* @return True if successful read operation. False otherwise.
*/
bool APDS9960::wireReadDataByte(uint8_t reg, uint8_t &val)
{
	val = wiringPiI2CReadReg8(fd_, reg);
	return true;
}

/**
* @brief Reads a block (array) of bytes from the I2C device and register
*
* @param[in] reg the register to read from
* @param[out] val pointer to the beginning of the data
* @param[in] len number of bytes to read
* @return Number of bytes read. -1 on read error.
*/
int APDS9960::wireReadDataBlock(   uint8_t reg, 
uint8_t *val, 
unsigned int len)
{
	if(wiringPiI2CWrite(fd_, reg) < 0) {
		return -1;
	}

	unsigned char i = 0;
	for(i = 0; i < len; i++) {
		uint8_t dat;
		if((dat = wiringPiI2CRead(fd_)) < 0) {
			return -1;
		}
		val[i] = dat;
	}
	return i;
}
