Interface library for STMicro LSM303DLH 3-axis magnetometer w/ 3-axis acceleromter. Computes magnetic heading.

Dependents:   AVC_20110423

Files at this revision

API Documentation at this revision

Comitter:
shimniok
Date:
Tue Apr 12 18:21:44 2011 +0000
Parent:
1:48d83c63d1d9
Commit message:
Added option to set I2C frequency, disabled IRQ during write/read of mag/acc registers due to apparent conflicts with interrupts during testing

Changed in this revision

LSM303DLH.cpp Show annotated file Show diff for this revision Revisions of this file
LSM303DLH.h Show annotated file Show diff for this revision Revisions of this file
diff -r 48d83c63d1d9 -r aea5caec809c LSM303DLH.cpp
--- a/LSM303DLH.cpp	Fri Apr 08 07:29:51 2011 +0000
+++ b/LSM303DLH.cpp	Tue Apr 12 18:21:44 2011 +0000
@@ -69,18 +69,26 @@
 bool LSM303DLH::read_reg(int addr_i2c,int addr_reg, char *v)
 {
     char data = addr_reg; 
-    if ((LSM303DLH::_compass.write(addr_i2c, &data, 1) == 0) && (LSM303DLH::_compass.read(addr_i2c, &data, 1) == 0)){
+    bool result = false;
+    
+    __disable_irq();
+    if ((_compass.write(addr_i2c, &data, 1) == 0) && (_compass.read(addr_i2c, &data, 1) == 0)){
         *v = data;
-        return true;
+        result = true;
     }
-    return false;
+    __enable_irq();
+    return result;
 }
 
 bool LSM303DLH::read_reg_short(int addr_i2c,int addr_reg, short *v)
 {
     char *pv = (char *)v;
-    read_reg(addr_i2c,addr_reg+0,pv+1);
-    return read_reg(addr_i2c,addr_reg+1,pv+0);
+    bool result;
+    
+    result =  read_reg(addr_i2c,addr_reg+0,pv+1);
+    result &= read_reg(addr_i2c,addr_reg+1,pv+0);
+  
+    return result;
 }
 
 LSM303DLH::LSM303DLH(PinName sda, PinName scl):
@@ -134,13 +142,22 @@
 {
     short a_x, a_y, a_z;
     short m_x, m_y, m_z;
+    //Timer t;
+    //int usec1, usec2;
     
+    //t.reset();
+    //t.start();
+
+    //usec1 = t.read_us();
     read_reg_short(addr_acc, OUT_X_A, &a_x);
     read_reg_short(addr_acc, OUT_Y_A, &a_y);
     read_reg_short(addr_acc, OUT_Z_A, &a_z);
     read_reg_short(addr_mag, OUT_X_M, &m_x);
     read_reg_short(addr_mag, OUT_Y_M, &m_y);
     read_reg_short(addr_mag, OUT_Z_M, &m_z);
+    //usec2 = t.read_us();
+    
+    //if (debug) debug->printf("%d %d %d\n", usec1, usec2, usec2-usec1);
 
     // Perform simple lowpass filtering
     // Intended to stabilize heading despite
@@ -195,3 +212,8 @@
     
     return heading;
 }
+
+void LSM303DLH::frequency(int hz)
+{
+    _compass.frequency(hz);
+}
\ No newline at end of file
diff -r 48d83c63d1d9 -r aea5caec809c LSM303DLH.h
--- a/LSM303DLH.h	Fri Apr 08 07:29:51 2011 +0000
+++ b/LSM303DLH.h	Tue Apr 12 18:21:44 2011 +0000
@@ -63,7 +63,6 @@
  */
 class LSM303DLH {
     public:
-    
         /** Create a new interface for an LSM303DLH
          *
          * @param sda is the pin for the I2C SDA line
@@ -115,6 +114,12 @@
          */
         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;