File content as of revision 0:726b77a319d8:

/*
 * MAX44009 Ambient Light Sensor with ADC library
 *
 *
 * Copyright (c) 2013 Davy Van Belle, MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
 * and associated documentation files (the "Software"), to deal in the Software without restriction, 
 * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or 
 * substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/** @file
 * @brief MAX44009 I2C
 */
 
#include "mbed.h"
#include "MAX44009.h"
 
    /** init MAX44009 class
     * @param *i2c pointer to I2C serial interface
     * @param addr sensor I2C address
     */
    MAX44009::MAX44009 (I2C* i2c, char addr)
    {
        _i2c = i2c;
        _addr = addr;
    }

    /** Set configuration register for the device
     * @param config desired configuration register bits
     * BIT 7 - CONT: 1 = continuous mode, 0 = single measurement
     * BIT 6 - MANUAL: 1 = CDR, TIM[2:0] set by user, 0 = CDR, TIM[2:0] set by internal autorange
     * BIT [5:4] - Not Used
     * BIT 3 - CDR: 1 = Current divided by 8. (High-brightness), 0 = Current not divided.
     * BIT [2:0] - TIM: Integration Time. See datasheet.
     */
     
    void MAX44009::setConfig (char config)
    {
        char cmd[2];
        cmd[0] = CONFIG;
        cmd[1] = config;
        _i2c->write(_addr,cmd,2);
    }
        
    /** Get device INT_STATUS register
     * BIT 0 : 0 = No interrupt event occurred, 1 = Ambient light intensity is outside the threshold range. 
     */  
    char MAX44009::getIntStatus()
    {
        char status;
        char cmd = INT_STATUS;
        _i2c->write(_addr,&cmd,1,true);
        _i2c->read(_addr+1,&status,1);
        return status;
    }

    /** Set device INT_ENABLE register
     * @param Enable  BIT 0 : 0 = INT pin and INTS bit not effected if an interrupt event occurred, 1 = INT pin pulled low and INTS bit is set if interrupt occurred. /
     */  
    void MAX44009::setIntEnable(bool Enable)
    {
        char cmd[2];
        cmd[0] = INT_ENABLE;
        cmd[1] = 0x00 | Enable;
        _i2c->write(_addr,cmd,2);
    }

    /** Get LUX reading from ADC
     *
     */
    float MAX44009::getLUXReading()
    {
    char buff[2];
    char cmd[2];
    char expo,mant;
    float lux;
    
    cmd[0] = LUX_HIGH_B;
    cmd[1] = LUX_LOW_B;
    
    _i2c->write(_addr,&cmd[0],1,true);
    _i2c->read(_addr+1,&buff[0],1,true);
    _i2c->write(_addr,&cmd[1],1,true);
    _i2c->read(_addr+1,&buff[1],1);
    
    expo = (buff[0] & 0xF0) >> 4;
    mant = ((buff[0] & 0x0F) << 4) | (buff[1] & 0x0F) ;
    
    lux = pow((double)2,(double)expo) * mant * 0.045;
    
    return lux;
    }
    
    /** Set upper threshold
    * @param threshold set upper threshold value. Further info, see datasheet
    */
    void MAX44009::setUpperThres(char threshold)
    {
        char cmd[2];
        cmd[0] = UP_THRESH_HIGH_B;
        cmd[1] = threshold;
        _i2c->write(_addr,cmd,2);
    }
    
    /** Set lower threshold
    * @param threshold set lower threshold value. Further info, see datasheet
    */
    void MAX44009::setLowerThres(char threshold)
    {
        char cmd[2];
        cmd[0] = LOW_THRESH_HIGH_B;
        cmd[1] = threshold;
        _i2c->write(_addr,cmd,2);    
    }
    
    /** Set Threshold time
    * @param time set time to trigger interrupt if value is below or above threshold value. Further info, see datasheet
    */
    void MAX44009::setThresTimer(char time)
    {
        char cmd[2];
        cmd[0] = THRESH_TIMER;
        cmd[1] = time;
        _i2c->write(_addr,cmd,2);       
    }
    
    /*
    float operator= (float d)
    {
        return this.getLUXReading();
    }  
    */