Diff: LSM303DLH/LSM303DLH.h

Revision:

3:f3796683b4c9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM303DLH/LSM303DLH.h	Sun May 06 05:14:30 2012 +0000
@@ -0,0 +1,138 @@
+#include "mbed.h"
+#include "vector.h"
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+/** Tilt-compensated compass interface Library for the STMicro LSM303DLH 3-axis magnetometer, 3-axis acceleromter
+ *
+ * Michael Shimniok http://bot-thoughts.com
+ *
+ * Based on test program by @tosihisa and 
+ *
+ * Pololu sample library for LSM303DLH breakout by ryantm:
+ *
+ * Copyright (c) 2011 Pololu Corporation. For more information, see
+ *
+ * http://www.pololu.com/
+ * http://forum.pololu.com/
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * @code
+ * #include "mbed.h"
+ * #include "LSM303DLH.h"
+ *
+ * Serial debug(USBTX,USBRX);
+ * LSM303DLH compass(p28, p27);
+ *
+ * int main() {
+ *   float hdg;
+ *   debug.format(8,Serial::None,1);
+ *   debug.baud(115200);
+ *   debug.printf("LSM303DLH Test\x0d\x0a");
+ *   compass.setOffset(29.50, -0.50, 4.00); // example calibration
+ *   compass.setScale(1.00, 1.03, 1.21);    // example calibration
+ *   while(1) {
+ *     hdg = compass.heading();
+ *     debug.printf("Heading: %.2f\n", hdg);
+ *     wait(0.1);
+ *   }
+ * }
+ * @endcode
+ */
+class LSM303DLH {
+    public:
+        /** Create a new interface for an LSM303DLH
+         *
+         * @param sda is the pin for the I2C SDA line
+         * @param scl is the pin for the I2C SCL line
+         */
+        LSM303DLH(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 raw accelerometer and compass 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(vector &a, vector &m);
+        
+        /** returns the magnetic heading with respect to the y axis
+         *
+         */
+        float heading(void);
+        
+        /** returns the heading with respect to the specified vector
+         *
+         */
+        float heading(vector from);
+    
+        /** 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 _compass;
+        float _offset_x;
+        float _offset_y;
+        float _offset_z;
+        float _scale_x;
+        float _scale_y;
+        float _scale_z;
+        long _filt_ax;
+        long _filt_ay;
+        long _filt_az;
+       
+        bool write_reg(int addr_i2c,int addr_reg, char v);
+        bool read_reg(int addr_i2c,int addr_reg, char *v);
+        bool read_reg_short(int addr_i2c,int addr_reg, short *v);
+};