Bo-Jhang Ho
/
mbed_test_fastest_rate
fastest sampling rate
Diff: MAG3110/MAG3110.cpp
- Revision:
- 0:459f1731fa6a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MAG3110/MAG3110.cpp Mon Feb 03 02:45:03 2014 +0000 @@ -0,0 +1,91 @@ + +#include "MAG3110.h" +#include "mbed.h" + +/****************************************************************************** + * Constructors + ******************************************************************************/ +MAG3110::MAG3110(PinName sda, PinName scl, int addr): _i2c(sda, scl), + _i2c_address(addr), _pc(NULL), _debug(false) +{ + begin(); +} + +MAG3110::MAG3110(PinName sda, PinName scl, Serial *pc): _i2c(sda, scl), + _i2c_address(0x1D), _pc(pc), _debug(true) +{ + begin(); +} + +void MAG3110::begin() +{ + char cmd[2]; + + cmd[0] = MAG_CTRL_REG2; + cmd[1] = 0x80; + _i2c.write(_i2c_address, cmd, 2); + + cmd[0] = MAG_CTRL_REG1; + cmd[1] = MAG_3110_SAMPLE80+MAG_3110_OVERSAMPLE2+MAG_3110_ACTIVE; + _i2c.write(_i2c_address, cmd, 2); + + // No adjustment initially + _avgX = 0; + _avgY = 0; +} + +// Read a single byte form 8 bit register, return as int +int MAG3110::readReg(char regAddr) +{ + char cmd[1]; + + cmd[0] = regAddr; + _i2c.write(_i2c_address, cmd, 1); + + cmd[0] = 0x00; + _i2c.read(_i2c_address, cmd, 1); + return (int)( cmd[0]); +} + + +// read a register per, pass first reg value, reading 2 bytes increments register +// Reads MSB first then LSB +int MAG3110::readVal(char regAddr) +{ + char cmd[2]; + + cmd[0] = regAddr; + _i2c.write(_i2c_address, cmd, 1); + + cmd[0] = 0x00; + cmd[1] = 0x00; + _i2c.read(_i2c_address, cmd, 2); + return (int)( (cmd[1]|(cmd[0] << 8))); //concatenate the MSB and LSB +} + + +float MAG3110::getHeading() +{ + int xVal = readVal(MAG_OUT_X_MSB); + int yVal = readVal(MAG_OUT_Y_MSB); + return (atan2((double)(yVal - _avgY),(double)(xVal - _avgX)))*180/PI; +} + +void MAG3110::getValues(int *xVal, int *yVal, int *zVal) +{ + *xVal = readVal(MAG_OUT_X_MSB); + *yVal = readVal(MAG_OUT_Y_MSB); + *zVal = readVal(MAG_OUT_Z_MSB); +} + + +void MAG3110::setCalibration(int minX, int maxX, int minY, int maxY ) +{ + _avgX=(maxX+minX)/2; + _avgY=(maxY+minY)/2; +} + + + + +