MAX44000.cpp

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00033 
00034 #include "MAX44000.h"
00035 
00036 /***** Definitions *****/
00037 #define I2C_ADDR            (0x94) // 1001_010x
00038 
00039 //******************************************************************************
00040 MAX44000::MAX44000(PinName sda, PinName scl)
00041 {
00042     i2c_ = new I2C(sda, scl);
00043     i2c_owner = true;
00044 
00045     i2c_->frequency(400000);
00046 }
00047 
00048 //******************************************************************************
00049 MAX44000::MAX44000(I2C *i2c) :
00050     i2c_(i2c)
00051 {
00052     i2c_owner = false;
00053 }
00054 
00055 //******************************************************************************
00056 MAX44000::~MAX44000()
00057 {
00058     if(i2c_owner) {
00059         delete i2c_;
00060     }
00061 }
00062 
00063 //******************************************************************************
00064 int MAX44000::init(MAX44000::modes_t mode, MAX44000::alstim_t alstim, MAX44000::alspga_t alspga, MAX44000::drive_t drive)
00065 {
00066     char data[2];
00067 
00068     data[0] = REG_RX_CONFIG;
00069     data[1] = 0xF0 | ((alstim & 0x03)<<2) | (alspga & 0x03);
00070     if (i2c_->write(I2C_ADDR, data, 2) != 0) {
00071         return -1;
00072     }
00073 
00074     data[0] = REG_TX_CONFIG;
00075     data[1] = (drive & 0x0F);
00076     if (i2c_->write(I2C_ADDR, data, 2) != 0) {
00077         return -1;
00078     }
00079 
00080     data[0] = REG_MAIN_CONFIG;
00081     data[1] = ((mode & 0x07)<<2) | (1<<5);  // Set bit 5 to use factory trim data
00082     if (i2c_->write(I2C_ADDR, data, 2) != 0) {
00083         return -1;
00084     }
00085 
00086     return 0;
00087 }
00088 
00089 //******************************************************************************
00090 int MAX44000::writeReg(MAX44000::registers_t reg_addr, char reg_data)
00091 {
00092     char data[2];
00093 
00094     data[0] = reg_addr;
00095     data[1] = reg_data;
00096     if (i2c_->write(I2C_ADDR, data, 2) != 0) {
00097         return -1;
00098     }
00099 
00100     return 0;
00101 }
00102 
00103 //******************************************************************************
00104 int MAX44000::readReg(MAX44000::registers_t reg_addr)
00105 {
00106     char data;
00107 
00108     data = reg_addr;
00109     if (i2c_->write(I2C_ADDR, &data, 1, true) != 0) {
00110         return -1;
00111     }
00112 
00113     if (i2c_->read(I2C_ADDR, &data, 1) != 0) {
00114         return -1;
00115     }
00116 
00117     return (0x0 + data);
00118 }
00119 
00120 //******************************************************************************
00121 int MAX44000::readALS(void)
00122 {
00123     char data;
00124     int alsData;
00125 
00126     data = REG_ALS_DATA_HIGH;
00127     if (i2c_->write(I2C_ADDR, &data, 1, true) != 0) {
00128         return -1;
00129     }
00130 
00131     if (i2c_->read(I2C_ADDR, &data, 1, true) != 0) {  // must use repeated start to protect low byte data
00132         return -1;
00133     }
00134 
00135     if (data & 0x40) { // if the overflow bit is set
00136         return -1;
00137     }
00138 
00139     alsData = (data << 8);
00140     data = REG_ALS_DATA_LOW;
00141     if (i2c_->write(I2C_ADDR, &data, 1, true) != 0) {
00142         return -1;
00143     }
00144 
00145     if (i2c_->read(I2C_ADDR, &data, 1) != 0) {
00146         return -1;
00147     }
00148 
00149     alsData += data;
00150     return alsData;
00151 }