Interface library for ST LSM303DLM 3-axis magnetometer/accelerometer
Dependents: AVC_2012 m3pi_Kompass Fish_2014Fall Fish_2014Fall ... more
Revision 0:faef9e4c8bea, committed 2012-01-20
- Comitter:
- shimniok
- Date:
- Fri Jan 20 23:47:25 2012 +0000
- Child:
- 1:fc5c9258ec45
- Commit message:
- Initial version
Changed in this revision
LSM303DLM.cpp | Show annotated file Show diff for this revision Revisions of this file |
LSM303DLM.h | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/LSM303DLM.cpp Fri Jan 20 23:47:25 2012 +0000 @@ -0,0 +1,63 @@ +#include "mbed.h" +#include "LSM303DLM.h" +#include "stdio.h" + +#define MAG_ADDRESS 0x3C +#define ACC_ADDRESS 0x30 + +LSM303DLM::LSM303DLM(PinName sda, PinName scl): _device(sda, scl) +{ + _device.frequency(400000); + init(); +} + +void LSM303DLM::init() +{ + // init mag + // continuous conversion mode + _data[0] = MR_REG_M; + _data[1] = 0x00; + if (!_device.write(MAG_ADDRESS, _data, 2)) + fprintf(stdout, "MR_REG_M: no ack\n"); + // data rate 75hz + _data[0] = CRA_REG_M; + _data[1] = 0x18; // 0b00011000 + if (_device.write(MAG_ADDRESS, _data, 2)) + fprintf(stdout, "CRA_REG_M: no ack\n"); + + // init acc + // data rate 100hz + _data[0] = CTRL_REG1_A; + _data[1] = 0x2F; // 0b00101111 + if (!_device.write(ACC_ADDRESS, _data, 2)) + fprintf(stdout, "CTRL_REG1_A: no ack\n"); +} + +void LSM303DLM::read(int a[3], int m[3]) +{ + readAcc(a); + readMag(m); +} + +void LSM303DLM::readAcc(int a[3]) +{ + _data[0] = OUT_X_L_A | (1<<7); + _device.write(ACC_ADDRESS, _data, 1); + _device.read(ACC_ADDRESS, _data, 6); + + // 12-bit values + a[0] = (short) (_data[0] | _data[1]<<8)>>4; + a[1] = (short) (_data[2] | _data[3]<<8)>>4; + a[2] = (short) (_data[4] | _data[5]<<8)>>4; +} + +void LSM303DLM::readMag(int m[3]) +{ + _data[0] = OUT_X_H_M; + _device.write(MAG_ADDRESS, _data, 1); + _device.read(MAG_ADDRESS, _data, 6); + + m[0] = (short) _data[0]<<8 | _data[1]; // X + m[1] = (short) _data[4]<<8 | _data[5]; // Y + m[2] = (short) _data[2]<<8 | _data[3]; // Z +} \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/LSM303DLM.h Fri Jan 20 23:47:25 2012 +0000 @@ -0,0 +1,130 @@ +#ifndef __LSM303DLM_H +#define __LSM303DLM_H + +#include "mbed.h" + +// register addresses + +#define CTRL_REG1_A 0x20 +#define CTRL_REG2_A 0x21 +#define CTRL_REG3_A 0x22 +#define CTRL_REG4_A 0x23 +#define CTRL_REG5_A 0x24 +#define CTRL_REG6_A 0x25 // DLHC only +#define HP_FILTER_RESET_A 0x25 // DLH, DLM only +#define REFERENCE_A 0x26 +#define STATUS_REG_A 0x27 + +#define OUT_X_L_A 0x28 +#define OUT_X_H_A 0x29 +#define OUT_Y_L_A 0x2A +#define OUT_Y_H_A 0x2B +#define OUT_Z_L_A 0x2C +#define OUT_Z_H_A 0x2D + +#define INT1_CFG_A 0x30 +#define INT1_SRC_A 0x31 +#define INT1_THS_A 0x32 +#define INT1_DURATION_A 0x33 +#define INT2_CFG_A 0x34 +#define INT2_SRC_A 0x35 +#define INT2_THS_A 0x36 +#define INT2_DURATION_A 0x37 + +#define CRA_REG_M 0x00 +#define CRB_REG_M 0x01 +#define MR_REG_M 0x02 + +#define OUT_X_H_M 0x03 +#define OUT_X_L_M 0x04 +#define OUT_Y_H_M 0x07 +#define OUT_Y_L_M 0x08 +#define OUT_Z_H_M 0x05 +#define OUT_Z_L_M 0x06 + +#define SR_REG_M 0x09 +#define IRA_REG_M 0x0A +#define IRB_REG_M 0x0B +#define IRC_REG_M 0x0C + +#define WHO_AM_I_M 0x0F + +#define OUT_Z_H_M 0x05 +#define OUT_Z_L_M 0x06 +#define OUT_Y_H_M 0x07 +#define OUT_Y_L_M 0x08 + +/** Tilt-compensated compass interface Library for the STMicro LSM303DLm 3-axis magnetometer, 3-axis acceleromter + * @author Michael Shimniok http://www.bot-thoughts.com/ + */ +class LSM303DLM { + + public: + /** Create a new interface for an LSM303DLM + * + * @param sda is the pin for the I2C SDA line + * @param scl is the pin for the I2C SCL line + */ + LSM303DLM(PinName sda, PinName scl); + + /** sets the x, y, and z offset corrections for hard iron calibration + * + * Calibration details here: + * http://mbed.org/users/shimniok/notebook/quick-and-dirty-3d-compass-calibration/ + * + * If you gather raw magnetometer data and find, for example, x is offset + * by hard iron by -20 then pass +20 to this member function to correct + * for hard iron. + * + * @param x is the offset correction for the x axis + * @param y is the offset correction for the y axis + * @param z is the offset correction for the z axis + */ + void setOffset(float x, float y, float z); + + /** sets the scale factor for the x, y, and z axes + * + * Calibratio details here: + * http://mbed.org/users/shimniok/notebook/quick-and-dirty-3d-compass-calibration/ + * + * Sensitivity of the three axes is never perfectly identical and this + * function can help to correct differences in sensitivity. You're + * supplying a multipler such that x, y and z will be normalized to the + * same max/min values + */ + void setScale(float x, float y, float z); + + /** read the calibrated accelerometer and magnetometer values + * + * @param a is the accelerometer 3d vector, written by the function + * @param m is the magnetometer 3d vector, written by the function + */ + void read(int a[3], int m[3]); + + /** read the calibrated accelerometer values + * + * @param a is the accelerometer 3d vector, written by the function + */ + void readAcc(int a[3]); + + /** read the calibrated magnetometer values + * + * @param m is the magnetometer 3d vector, written by the function + */ + void readMag(int m[3]); + + /** sets the I2C bus frequency + * + * @param frequency is the I2C bus/clock frequency, either standard (100000) or fast (400000) + */ + void frequency(int hz); + + private: + I2C _device; + char _data[6]; + /** initializes the device + */ + void init(); +}; + +#endif \ No newline at end of file