IMU.h

00001 #ifndef IMU_H
00002 #define IMU_H
00003 
00004 #include "mbed.h"
00005 
00006 // definitions for the gyro sensor
00007 #define L3GD20_ADDR           0xD6
00008 #define L3GD20_CTRL_REG1      0x20
00009 #define L3GD20_CTRL_REG4      0x23
00010 #define L3GD20_STATUS_REG     0x27
00011 #define L3GD20_OUT_X_L        0x28
00012 #define L3GD20_RANGE_250DPS   0x00                // Measurement range selected by CTRL_REG4
00013 #define L3GD20_RANGE_500DPS   0x01                // Default range = 250 Degree-per-Second = 0.7 rev/second
00014 #define L3GD20_RANGE_2000DPS  0x02                // Range determines Sensitivity
00015 #define L3GD20_SENSITIVITY_250DPS   0.00875       // Roughly 22/256 for fixed point match
00016 #define L3GD20_SENSITIVITY_500DPS   0.0175        // Roughly 45/256
00017 #define L3GD20_SENSITIVITY_2000DPS  0.070         // Roughly 18/256
00018 #define L3GD20_DPS_TO_RADS          0.017453293   // = pi/180 degrees/s to rad/s multiplier
00019 
00020 
00021 // definitions for the accelerometer
00022 #define LSM303_A_ADDR            0x32      // address for writing. +1 for reading, see manual p. 20/42.
00023 #define LSM303_A_CTRL_REG1       0x20
00024 #define LSM303_A_CTRL_REG4       0x23
00025 #define LSM303_A_OUT_X_L         0x28
00026 #define LSM303_A_FS_2G           0x00      // Full Scale measuremetn range - selected by CTRL_REG4
00027 #define LSM303_A_Sensitivity     0.001     // Linear acceleration sensitivity
00028 #define LSM303_A_GRAVITY_EARTH   9.80665   // Earth's gravity in m/s^2 upon calibration of sensor
00029 
00030 // definitions for the magnetic sensor
00031 #define LSM303_M_ADDR        0x3C // address for writing. +1 for reading, see datasheet p. 21/42.
00032 #define LSM303_M_CRA_REG     0x00 
00033 #define LSM303_M_CRB_REG     0x01 
00034 #define LSM303_M_MR_REG      0x02
00035 #define LSM303_M_OUT_X_H     0x03        // Watch out: order of H and L reversed 
00036 #define LSM303_M_FS_13G      0x01        // Full Scale measuremetn range - selected by CRB_REG
00037 #define LSM303_M_Sensitivity  1100       // Corresponding sensitivity = 1100 Bits/Gauss
00038 
00039 
00040 class IMU
00041 {
00042   public:
00043 /* constructor */
00044     IMU(PinName sda, PinName scl);
00045 
00046 /* accessible functions */
00047     char init(void);
00048     char readData(float *);
00049     void filterData(float *, double *);
00050     
00051   private:
00052       I2C _i2c;
00053       char address;
00054       int16_t L3GD20_biasX;  /* digit counts */
00055       int16_t L3GD20_biasY;
00056       int16_t L3GD20_biasZ;
00057       double  g_0;
00058       double  FF[3];
00059       double  FD[6][9]; 
00060 };
00061 
00062 #endif