MAG3110.cpp

00001 
00002 #include "MAG3110.h"
00003 #include "mbed.h"
00004 
00005 /******************************************************************************
00006  * Constructors
00007  ******************************************************************************/
00008 MAG3110::MAG3110(PinName sda, PinName scl,float dateRate, int overSample): _i2c(sda, scl), 
00009     _i2c_address(0x0E<<1), _pc(NULL), _debug(false)
00010 {   
00011     Setdr(dateRate);
00012     Setosr(overSample); 
00013     begin();
00014 }
00015 
00016 MAG3110::MAG3110(PinName sda, PinName scl): _i2c(sda, scl), 
00017     _i2c_address(0x0E<<1), _pc(NULL), _debug(false),dr(MAG_3110_SAMPLE80),osr(MAG_3110_OVERSAMPLE2)
00018 {
00019     begin();
00020 }
00021 
00022 MAG3110::MAG3110(PinName sda, PinName scl, Serial *pc): _i2c(sda, scl), 
00023    _i2c_address(0x0E<<1), _pc(pc), _debug(true),dr(MAG_3110_SAMPLE80),osr(MAG_3110_OVERSAMPLE2)
00024 {
00025     begin();
00026 }
00027 
00028 void MAG3110::begin()
00029 {
00030     
00031     char cmd[2];
00032 
00033     cmd[0] = MAG_CTRL_REG2;
00034     cmd[1] = 0x80;
00035     _i2c.write(_i2c_address, cmd, 2);
00036 
00037     cmd[0] = MAG_CTRL_REG1;
00038 //    cmd[1] = MAG_3110_SAMPLE80+MAG_3110_OVERSAMPLE2+MAG_3110_ACTIVE;
00039     cmd[1] = dr+osr+MAG_3110_ACTIVE;
00040     _i2c.write(_i2c_address, cmd, 2);
00041     
00042     // No adjustment initially
00043     _avgX = 0;
00044     _avgY = 0;
00045 }
00046 
00047 // Read a single byte form 8 bit register, return as int
00048 int MAG3110::readReg(char regAddr)
00049 {
00050     char cmd[1];
00051 
00052     cmd[0] = regAddr;
00053     _i2c.write(_i2c_address, cmd, 1);
00054 
00055     cmd[0] = 0x00;
00056     _i2c.read(_i2c_address, cmd, 1);
00057     return (int)( cmd[0]);
00058 }
00059 
00060 
00061 // read a register per, pass first reg value, reading 2 bytes increments register
00062 // Reads MSB first then LSB
00063 int MAG3110::readVal(char regAddr)
00064 {
00065     char cmd[2];
00066 
00067     cmd[0] = regAddr;
00068     _i2c.write(_i2c_address, cmd, 1);
00069 
00070     cmd[0] = 0x00;
00071     cmd[1] = 0x00;
00072     _i2c.read(_i2c_address, cmd, 2);
00073     return (int)( (cmd[1]|(cmd[0] << 8))); //concatenate the MSB and LSB
00074 }
00075 
00076 
00077 float MAG3110::getHeading()
00078 {
00079     int xVal = readVal(MAG_OUT_X_MSB);
00080     int yVal = readVal(MAG_OUT_Y_MSB);
00081     return (atan2((double)(yVal - _avgY),(double)(xVal - _avgX)))*180/PI;
00082 }
00083 
00084 void MAG3110::getValues(int *xVal, int *yVal, int *zVal)
00085 {
00086     *xVal = readVal(MAG_OUT_X_MSB);
00087     *yVal = readVal(MAG_OUT_Y_MSB);
00088     *zVal = readVal(MAG_OUT_Z_MSB);
00089 }
00090 
00091 
00092 void MAG3110::setCalibration(int minX, int maxX, int minY, int maxY )
00093 {
00094     _avgX=(maxX+minX)/2;
00095     _avgY=(maxY+minY)/2;
00096 }
00097 
00098 void MAG3110::Setdr(float dateRate)
00099 {
00100         if (dateRate==80)
00101             dr=MAG_3110_SAMPLE80;
00102         else if(dateRate==40)
00103             dr=MAG_3110_SAMPLE40;
00104         else if(dateRate==20)
00105             dr=MAG_3110_SAMPLE20;
00106         else if(dateRate==10)
00107             dr=MAG_3110_SAMPLE10;
00108         else if(dateRate==5)
00109             dr=MAG_3110_SAMPLE5;
00110         else if(dateRate==2.5)
00111             dr=MAG_3110_SAMPLE2_5;
00112         else if(dateRate==1.25)
00113             dr=MAG_3110_SAMPLE1_25;
00114         else if(dateRate==0.625)
00115             dr=MAG_3110_SAMPLE0_625;
00116         else 
00117             dr=MAG_3110_SAMPLE80;
00118 }
00119 
00120 void MAG3110::Setosr(int overSample)
00121 {
00122        switch(overSample)
00123     {
00124         case 16:osr=MAG_3110_OVERSAMPLE1;break;
00125         case 32:osr=MAG_3110_OVERSAMPLE2;break;
00126         case 64:osr=MAG_3110_OVERSAMPLE3;break;
00127         case 128:osr=MAG_3110_OVERSAMPLE4;break;
00128         default:osr=MAG_3110_OVERSAMPLE2;break;
00129     }   
00130 }
00131 
00132 void MAG3110::Overwrite_dr_osr(float dateRate,int overSample)
00133 {
00134     char cmd[2];
00135     Setdr(dateRate);
00136     Setosr(overSample);
00137     cmd[0] = MAG_CTRL_REG1;
00138     cmd[1] = dr+osr+MAG_3110_ACTIVE;
00139     _i2c.write(_i2c_address, cmd, 2);
00140 }