Simple library for MAG3110 magenetometer as built into FRDM-KL46Z module;
Dependents: serialSENS magsensor_46_v2 fibbo_test_v1
Fork of MAG3110 by
Revision 0:63a8594a3866, committed 2013-05-19
- Comitter:
- SomeRandomBloke
- Date:
- Sun May 19 20:34:27 2013 +0000
- Child:
- 1:5a0e7a58d980
- Commit message:
- Initial library commit
Changed in this revision
MAG3110.cpp | Show annotated file Show diff for this revision Revisions of this file |
MAG3110.h | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MAG3110.cpp Sun May 19 20:34:27 2013 +0000 @@ -0,0 +1,87 @@ + +#include "MAG3110.h" +#include "mbed.h" + +/****************************************************************************** + * Constructors + ******************************************************************************/ +MAG3110::MAG3110(I2C *i2c): + _i2c_address(0x1D), _i2c(i2c),_pc(NULL), _debug(false) +{ + +} + +MAG3110::MAG3110(I2C *i2c, Serial *pc): + _i2c_address(0x1D), _i2c(i2c), _pc(pc), _debug(true) +{ + +} + +// 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 +} + + +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); +} + +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; +} + + + + +
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MAG3110.h Sun May 19 20:34:27 2013 +0000 @@ -0,0 +1,96 @@ +/* + * MAG3110 Sensor Library for mbed + * TODO: Add proper header + */ + +#ifndef MAG3110_H +#define MAG3110_H + +#include "mbed.h" + +#define PI 3.14159265359 + +#define MAG_ADDR 0x1D + +// define registers +#define MAG_DR_STATUS 0x00 +#define MAG_OUT_X_MSB 0x01 +#define MAG_OUT_X_LSB 0x02 +#define MAG_OUT_Y_MSB 0x03 +#define MAG_OUT_Y_LSB 0x04 +#define MAG_OUT_Z_MSB 0x05 +#define MAG_OUT_Z_LSB 0x06 +#define MAG_WHO_AM_I 0x07 +#define MAG_SYSMOD 0x08 +#define MAG_OFF_X_MSB 0x09 +#define MAG_OFF_X_LSB 0x0A +#define MAG_OFF_Y_MSB 0x0B +#define MAG_OFF_Y_LSB 0x0C +#define MAG_OFF_Z_MSB 0x0D +#define MAG_OFF_Z_LSB 0x0E +#define MAG_DIE_TEMP 0x0F +#define MAG_CTRL_REG1 0x10 +#define MAG_CTRL_REG2 0x11 + +// what should WHO_AM_I return? +#define MAG_3110_WHO_AM_I_VALUE 0xC4 + + +// Fields in registers +// CTRL_REG1: dr2,dr1,dr0 os1,os0 fr tm ac + +// Sampling rate from 80Hz down to 0.625Hz +#define MAG_3110_SAMPLE80 0 +#define MAG_3110_SAMPLE40 0x20 +#define MAG_3110_SAMPLE20 0x40 +#define MAG_3110_SAMPLE10 0x60 +#define MAG_3110_SAMPLE5 0x80 +#define MAG_3110_SAMPLE2_5 0xA0 +#define MAG_3110_SAMPLE1_25 0xC0 +#define MAG_3110_SAMPLE0_625 0xE0 + +// How many samples to average (lowers data rate) +#define MAG_3110_OVERSAMPLE1 0 +#define MAG_3110_OVERSAMPLE2 0x08 +#define MAG_3110_OVERSAMPLE3 0x10 +#define MAG_3110_OVERSAMPLE4 0x18 + +// read only 1 byte per axis +#define MAG_3110_FASTREAD 0x04 +// do one measurement (even if in standby mode) +#define MAG_3110_TRIGGER 0x02 +// put in active mode +#define MAG_3110_ACTIVE 0x01 + +// CTRL_REG2: AUTO_MRST_EN _ RAW MAG_RST _ _ _ _ _ +// reset sensor after each reading +#define MAG_3110_AUTO_MRST_EN 0x80 +// don't subtract user offsets +#define MAG_3110_RAW 0x20 +// reset magnetic sensor after too-large field +#define MAG_3110_MAG_RST 0x10 + +// DR_STATUS Register ZYXOW ZOW YOW XOW ZYXDR ZDR YDR XDR +#define MAG_3110_ZYXDR 0x08 + +class MAG3110 +{ + private: + short _i2c_address; + I2C *_i2c; + Serial *_pc; + bool _debug; + int _avgX, _avgY; //, _newX, _tempXmin, _tempXmax, _newY, _tempYmin, _tempYmax; + + + public: + MAG3110(I2C *i2c); + MAG3110(I2C *i2c, Serial *pc); //pass serial for debug + void begin(); + int readReg(char regAddr); + int readVal(char regAddr); + float getHeading(); + void getValues(int *xVal, int *yVal, int *zVal); + void setCalibration(int minX, int maxX, int minY, int maxY); +}; +#endif \ No newline at end of file