Diff: LSM303.cpp

Revision:

0:dc35364e2291

Child:

1:3272ece36ce1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM303.cpp	Thu Apr 12 13:47:23 2012 +0000
@@ -0,0 +1,209 @@
+/* mbed LSM303 Library version 0beta1
+ * Copyright (c) 2012 bengo
+ *
+ * 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.
+ */
+ 
+#include <LSM303.h>
+#include <cmath>
+
+// LSM303 I2C addresses
+const int LSM303::ACC_ADDRESS = 0x30;
+const int LSM303::MAG_ADDRESS = 0x3c;
+// LSM303 register addresses
+const int LSM303::ACC_CTRL_REG1 = 0x20;
+const int LSM303::ACC_CTRL_REG2 = 0x21;
+const int LSM303::ACC_CTRL_REC3 = 0x22;
+const int LSM303::ACC_CTRL_REG4 = 0x23;
+const int LSM303::ACC_CTRL_REG5 = 0x24;
+const int LSM303::ACC_HP_FILTER_RESET = 0x25;
+const int LSM303::ACC_REFERENCE = 0x26;
+const int LSM303::ACC_STATUS_REG = 0x27;
+const int LSM303::ACC_OUT_X_L = 0x28;
+const int LSM303::ACC_OUT_X_H = 0x29;
+const int LSM303::ACC_OUT_Y_L = 0x2a;
+const int LSM303::ACC_OUT_Y_H = 0x2b;
+const int LSM303::ACC_OUT_Z_L = 0x2c;
+const int LSM303::ACC_OUT_Z_H = 0x2d;
+const int LSM303::ACC_INT1_CFG = 0x30;
+const int LSM303::ACC_INT1_SOURCE = 0x31;
+const int LSM303::ACC_INT1_THS = 0x32;
+const int LSM303::ACC_INT1_DURATION = 0x33;
+const int LSM303::ACC_INT2_CFG = 0x34;
+const int LSM303::ACC_INT2_SOURCE = 0x35;
+const int LSM303::ACC_INT2_THS = 0x36;
+const int LSM303::ACC_INT2_DURATION = 0x37;
+const int LSM303::MAG_CRA_REG = 0x00;
+const int LSM303::MAG_CRB_REG = 0x01;
+const int LSM303::MAG_MR_REG = 0x02;
+const int LSM303::MAG_OUT_X_H = 0x03;
+const int LSM303::MAG_OUT_X_L = 0x04;
+const int LSM303::MAG_OUT_Y_H = 0x07;
+const int LSM303::MAG_OUT_Y_L = 0x08;
+const int LSM303::MAG_OUT_Z_H = 0x05;
+const int LSM303::MAG_OUT_Z_L = 0x6;
+const int LSM303::MAG_SR_REG = 0x9;
+const int LSM303::MAG_IRA_REG = 0x0a;
+const int LSM303::MAG_IRB_REG = 0x0b;
+const int LSM303::MAG_IRC_REG = 0x0c;
+const int LSM303::MAG_WHO_AM_I = 0x0f;
+//
+
+// -------------------------------------------
+LSM303::LSM303( PinName sda, PinName scl ) : _i2c( sda, scl ) {
+   // Get SA0 pin status
+   _bytes[0] = ACC_CTRL_REG1;
+   _i2c.write( ACC_ADDRESS, _bytes, 1 );
+   int sa0low = _i2c.read( ACC_ADDRESS+1, _bytes, 1 );
+   _bytes[0] = ACC_CTRL_REG1;
+   _i2c.write( ACC_ADDRESS+2, _bytes, 1 );
+   int sa0hig = _i2c.read( ACC_ADDRESS+2+1, _bytes, 1 );
+   if( sa0low == 0 && sa0hig != 0 ) {
+      _SA0Pad = 0x0;
+   }
+   else if( sa0low != 0 && sa0hig == 0 ) {
+      _SA0Pad = 0x2;
+   }
+   else {
+      _status = 1;
+      return;
+   }
+   // Check that you're talking with an LM303DLM device
+   _bytes[0] = MAG_WHO_AM_I;
+   _i2c.write( MAG_ADDRESS, _bytes, 1 );
+   _status = _i2c.read( MAG_ADDRESS+1, _bytes, 1 );   
+   if( _bytes[0] == 0x3c ) {
+      _status = 0;
+   }
+   else {
+      _status = 1;
+      return;
+   }
+   // Enable normal mode... 
+   // ... On accelerometer
+   this->accRegisterWrite( ACC_CTRL_REG1, 0x27 );
+   if( _status != 0 ) {
+      return;  
+   }
+   // ... And on magnetometer
+   this->magRegisterWrite( MAG_MR_REG, 0x00 );
+}
+LSM303::LSM303( void ) : _i2c( p9, p10 ) {}
+// -------------------------------------------
+int LSM303::accRegisterRead( int reg ) {
+  _bytes[0] = reg & 0xff;
+  _status = _i2c.write( ACC_ADDRESS + _SA0Pad, _bytes, 1 );
+  if( _status ==  0 ) {
+    _status = _i2c.read(  ACC_ADDRESS + _SA0Pad + 1, _bytes, 1 );
+    return( _bytes[0] );
+  }
+  return( 0 );
+}
+
+// -------------------------------------------  
+void LSM303::accRegisterWrite( int reg, char data ) {
+  _bytes[0] = reg & 0xff;
+  _bytes[1] = data & 0xff;
+  _status = _i2c.write( ACC_ADDRESS + _SA0Pad, _bytes, 2 );
+}
+
+// -------------------------------------------  
+int LSM303::magRegisterRead( int reg ) {
+  _bytes[0] = reg & 0xff;
+  _status = _i2c.write( MAG_ADDRESS, _bytes, 1 );
+  if( _status ==  0 ) {
+    _status = _i2c.read(  MAG_ADDRESS + 1, _bytes, 1 );
+    return( _bytes[0] );
+  }
+  return( 0 );
+}
+
+// -------------------------------------------  
+void LSM303::magRegisterWrite( int reg, char data ) {
+  _bytes[0] = reg & 0xff;
+  _bytes[1] = data & 0xff;
+  _status = _i2c.write( MAG_ADDRESS, _bytes, 2 );
+}
+
+
+// -------------------------------------------
+std::vector<short> LSM303::accRead( void ) {
+   std::vector<short> acc( 3, 0 );
+   _bytes[0] = ACC_OUT_X_L | (1<<7);
+   _status = _i2c.write( ACC_ADDRESS + _SA0Pad, _bytes, 1 );
+   if( _status == 0 ) {
+      _status = _i2c.read( ACC_ADDRESS + _SA0Pad + 1, _bytes, 6 );
+      if( _status == 0 ) {
+         for( int i=0; i<3; i++ ) {
+            acc[i] = ( short( _bytes[2*i] ) | short(_bytes[2*i+1]) << 8 );
+         }
+      }
+   } 
+   return( acc );
+}
+
+// -------------------------------------------
+std::vector<float> LSM303::acceleration( void ) {
+
+   const float cal[3][2] = { {  16291.5, -16245.4 }, {  16819.0, -16253.0 }, {  16994.8, -15525.6 } };
+   
+   std::vector<float> acc( 3, 0 );
+   int fs = ( this->accRegisterRead( ACC_CTRL_REG4 ) >> 4 ) & 0x3;
+   std::vector<short> a = this->accRead();
+   if( _status == 0 ) {
+      for( int i=0; i<3; i++ ) {
+         acc[i] = acc[i] * ( (cal[i][0] - cal[i][1]) / 32768. ) + (cal[i][0]+cal[i][1])/2.;
+         acc[i] = float( a[i] ) * pow(2.,(fs+1)) / 32768.;
+      }
+   }
+   return( acc );
+}  
+
+// -------------------------------------------
+std::vector<short> LSM303::magRead( void ) {
+   std::vector<short> mag( 3, 0 );
+   _bytes[0] = MAG_OUT_X_H;
+   _status = _i2c.write( MAG_ADDRESS, _bytes, 1 );
+   if( _status == 0 ) {
+      _status = _i2c.read( MAG_ADDRESS + 1, _bytes, 6 );
+      if( _status == 0 ) {
+         mag[0] = (short)( _bytes[0] << 8 ) | (short)( _bytes[1] );
+         mag[1] = (short)( _bytes[4] << 8 ) | (short)( _bytes[5] );
+         mag[2] = (short)( _bytes[2] << 8 ) | (short)( _bytes[3] );
+      }
+   } 
+   return( mag );
+}
+ 
+// ------------------------------------------- 
+std::vector<float> LSM303::magneticField( void ) {
+
+   float gainxy[] = { 1100., 855., 670., 450., 400., 330., 230. };
+   float gainz[]  = {  980., 760., 600., 400., 355., 295., 205. };
+   
+   std::vector<float> mag( 3, 0 );
+   int gn = ( this->magRegisterRead( MAG_CRB_REG ) >> 5 ) & 0x7;
+   std::vector<short> m = this->magRead();
+   if( _status == 0 ) {
+      mag[0] = float( m[0] ) / gainxy[gn-1];
+      mag[1] = float( m[1] ) / gainxy[gn-1];
+      mag[2] = float( m[2] ) / gainz[gn-1];
+   }
+   return( mag );
+}
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