TSL2591.cpp

00001 #include "TSL2591.h"
00002 
00003 TSL2591::TSL2591 (I2C& tsl2591_i2c, uint8_t tsl2591_addr):
00004     _i2c(tsl2591_i2c), _addr(tsl2591_addr<<1)
00005 {
00006     _init = false;
00007     _integ = TSL2591_INTT_100MS;
00008     _gain = TSL2591_GAIN_LOW;
00009 }
00010 /*
00011  *  Initialize TSL2591
00012  *  Checks ID and sets gain and integration time
00013  */
00014 bool TSL2591::init(void)
00015 {
00016     char write[] = {(TSL2591_CMD_BIT|TSL2591_REG_ID)};
00017     if(_i2c.write(_addr, write, 1, 0) == 0) {
00018         char read[1];
00019         _i2c.read(_addr, read, 1, 0);
00020         if(read[0] == TSL2591_ID) {
00021             _init = true;
00022             setGain(TSL2591_GAIN_LOW);
00023             setTime(TSL2591_INTT_100MS);
00024             disable();
00025             return true;
00026         }
00027     }
00028     return false;
00029 }
00030 /*
00031  *  Power On TSL2591
00032  */
00033 void TSL2591::enable(void)
00034 {
00035     char write[] = {(TSL2591_CMD_BIT|TSL2591_REG_ENABLE), (TSL2591_EN_PON|TSL2591_EN_AEN|TSL2591_EN_AIEN|TSL2591_EN_NPIEN)};
00036     _i2c.write(_addr, write, 2, 0);
00037 }
00038 /*
00039  *  Power Off TSL2591
00040  */
00041 void TSL2591::disable(void)
00042 {
00043     char write[] = {(TSL2591_CMD_BIT|TSL2591_REG_ENABLE), (TSL2591_EN_POFF)};
00044     _i2c.write(_addr, write, 2, 0);
00045 }
00046 /*
00047  *  Set Gain and Write
00048  *  Set gain and write time and gain
00049  */
00050 void TSL2591::setGain(tsl2591Gain_t gain)
00051 {
00052     enable();
00053     _gain = gain;
00054     char write[] = {(TSL2591_CMD_BIT|TSL2591_REG_CONTROL), (_integ|_gain)};
00055     _i2c.write(_addr, write, 2, 0);
00056     disable();
00057 }
00058 /*
00059  *  Set Integration Time and Write
00060  *  Set gain and write time and gain
00061  */
00062 void TSL2591::setTime(tsl2591IntegrationTime_t integ)
00063 {
00064     enable();
00065     _integ = integ;
00066     char write[] = {(TSL2591_CMD_BIT|TSL2591_REG_CONTROL), (_integ|_gain)};
00067     _i2c.write(_addr, write, 2, 0);
00068     disable();
00069 }
00070 /*
00071  *  Read ALS
00072  *  Read full spectrum, infrared, and visible
00073  */
00074 void TSL2591::getALS(void)
00075 {
00076     enable();
00077     for(uint8_t t=0; t<=_integ+1; t++) {
00078         wait(0.12);
00079     }
00080     char write1[] = {(TSL2591_CMD_BIT|TSL2591_REG_CHAN1_L)};
00081     _i2c.write(_addr, write1, 1, 0);
00082     char read1[2];
00083     _i2c.read(_addr, read1, 2, 0);
00084     char write2[] = {(TSL2591_CMD_BIT|TSL2591_REG_CHAN0_L)};
00085     _i2c.write(_addr, write2, 1, 0);
00086     char read2[2];
00087     _i2c.read(_addr, read2, 2, 0);
00088     rawALS = (((read1[1]<<8)|read1[0])<<16)|((read2[1]<<8)|read2[0]);
00089     disable();
00090     full = rawALS & 0xFFFF;
00091     ir = rawALS >> 16;
00092     visible = full - ir;
00093 }
00094 /*
00095  *  Calculate Lux
00096  */
00097 void TSL2591::calcLux(void)
00098 {
00099     float atime, again, cpl, lux1, lux2, lux3;
00100     if((full == 0xFFFF)|(ir == 0xFFFF)) {
00101         lux3 = 0;
00102         return;
00103     }
00104     switch(_integ) {
00105         case TSL2591_INTT_100MS:
00106             atime = 100.0F;
00107             break;
00108         case TSL2591_INTT_200MS:
00109             atime = 200.0F;
00110             break;
00111         case TSL2591_INTT_300MS:
00112             atime = 300.0F;
00113             break;
00114         case TSL2591_INTT_400MS:
00115             atime = 400.0F;
00116             break;
00117         case TSL2591_INTT_500MS:
00118             atime = 500.0F;
00119             break;
00120         case TSL2591_INTT_600MS:
00121             atime = 600.0F;
00122             break;
00123         default:
00124             atime = 100.0F;
00125             break;
00126     }
00127     switch(_gain) {
00128         case TSL2591_GAIN_LOW:
00129             again = 1.0F;
00130             break;
00131         case TSL2591_GAIN_MED:
00132             again = 25.0F;
00133             break;
00134         case TSL2591_GAIN_HIGH:
00135             again = 428.0F;
00136             break;
00137         case TSL2591_GAIN_MAX:
00138             again = 9876.0F;
00139             break;
00140         default:
00141             again = 1.0F;
00142             break;
00143     }
00144     cpl = (atime * again) / TSL2591_LUX_DF;
00145     lux1 = ((float)full - (TSL2591_LUX_COEFB * (float)ir)) / cpl;
00146     lux2 = (( TSL2591_LUX_COEFC * (float)full ) - ( TSL2591_LUX_COEFD * (float)ir)) / cpl;
00147     lux3 = lux1 > lux2 ? lux1 : lux2;
00148     lux = (uint32_t)lux3;
00149 }