Revision 5:c9ce1eeaf001, committed 2013-12-10

Comitter:

xeta05

Date:

Tue Dec 10 10:58:28 2013 +0000

Parent:

4:bc4e1201e092

Commit message:

*Corrected the XZY order instead of the previous XYZ to match the datasheet.; * Added Declination compensation by a define

Changed in this revision

diff -r bc4e1201e092 -r c9ce1eeaf001 HMC5883L.cpp
--- a/HMC5883L.cpp	Tue Nov 06 17:35:51 2012 +0000
+++ b/HMC5883L.cpp	Tue Dec 10 10:58:28 2013 +0000
@@ -1,6 +1,6 @@
 /*
  * @file HMC5883L.cpp
- * @author Tyler Weaver
+ * @author Oskar Lopez de Gamboa
  *
  * @section LICENSE
  *
@@ -22,11 +22,11 @@
  * @section DESCRIPTION
  *
  * HMC5883L 3-Axis Digital Compas IC
- * For use with the Sparkfun 9 Degrees of Freedom - Sensor Stick
+ * The library done by Tyler Weaver with:
  *
- * Datasheet:
- *
- * http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Magneto/HMC5883L-FDS.pdf
+ *  *Corrected the XZY order instead of the previous XYZ to match the datasheet.
+ *  *Added Declination compensation by a define
+ * 
  */
 
 #include "HMC5883L.h"
@@ -51,8 +51,9 @@
 {
     // init - configure your setup here
     setConfigurationA(AVG8_SAMPLES | OUTPUT_RATE_15); // 8 sample average, 15Hz, normal mode
-    setConfigurationB(0x20); // default 
+    setConfigurationB(0x20); // default gain
     setMode(CONTINUOUS_MODE); // continuous sample mode
+    wait(0.006);//wait 6ms as told in the datasheet
 }
 
 void HMC5883L::setConfigurationA(char config)
@@ -133,9 +134,11 @@
 {
     int16_t raw_data[3];
     getXYZ(raw_data);
-    double heading = atan2(static_cast<double>(raw_data[1]), static_cast<double>(raw_data[0])); // heading = arctan(Y/X)
+    //The  HMC5883L gives X Z Y order
+    double heading = atan2(static_cast<double>(raw_data[2]), static_cast<double>(raw_data[0])); // heading = arctan(Y/X)
     
-    // TODO: declenation angle compensation
+    
+    heading += DECLINATION_ANGLE;
     
     if(heading < 0.0) // fix sign
         heading += PI2;

diff -r bc4e1201e092 -r c9ce1eeaf001 HMC5883L.h
--- a/HMC5883L.h	Tue Nov 06 17:35:51 2012 +0000
+++ b/HMC5883L.h	Tue Dec 10 10:58:28 2013 +0000
@@ -1,6 +1,6 @@
 /*
  * @file HMC5883L.h
- * @author Tyler Weaver
+ * @author Oskar Lopez de Gamboa
  *
  * @section LICENSE
  *
@@ -22,11 +22,12 @@
  * @section DESCRIPTION
  *
  * HMC5883L 3-Axis Digital Compas IC
- * For use with the Sparkfun 9 Degrees of Freedom - Sensor Stick
+ * The library done by Tyler Weaver with:
  *
- * Datasheet:
+ *  *Corrected the XZY order instead of the previous XYZ to match the datasheet.
+ *  *Added Declination compensation by a define
+ * 
  *
- * http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Magneto/HMC5883L-FDS.pdf
  */
 
 #ifndef HMC5883L_H
@@ -83,6 +84,17 @@
 #define RAD_TO_DEG  (180.0/M_PI)
 #define DEG_TO_RAD  (M_PI/180.0)
 
+// Once you have your heading, you must then add your 'Declination Angle', 
+// which is  the 'Error' of the magnetic field in your location.
+// Find yours here: http://www.magnetic-declination.com/
+// Mine is:  -1° 13' WEST which is -1.2167 Degrees, or (which we need) 
+// 0,021234839232597676519238237683278  radians, I will use 0.02123
+// If you cannot find your Declination, put 0, your compass will be slightly off.
+
+#define  DECLINATION_ANGLE -0.02123
+//#define  DECLINATION_ANGLE 0
+
+
 /**
  * The HMC5883L 3-Axis Digital Compass IC
  */
@@ -193,8 +205,9 @@
     
     /**
     * Function for retriaval of the raw data
+    * Caution!!  the HMC5883L gives you the data in XZY order
     *
-    * @param output buffer that is atleast 3 in length
+    * @param output buffer that is at least 3 in length
     */
     void getXYZ(int16_t raw[3]);
     
@@ -213,7 +226,7 @@
     * Compass must be held flat and away from an magnetic field generating
     * devices such as cell phones and speakers.
     *
-    * TODO: declenation angle compensation
+    * 
     * 
     * @returns heading in radians
     */
@@ -225,7 +238,7 @@
     * Compass must be held flat and away from an magnetic field generating
     * devices such as cell phones and speakers.
     *
-    * TODO: declenation angle compensation
+    * 
     * 
     * @returns heading in degrees
     */