Diff: Sensors/Gyro/L3G4200D.cpp

Revision:

0:1c15748ff0e1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Sensors/Gyro/L3G4200D.cpp	Sat Jul 19 05:35:58 2014 +0000
@@ -0,0 +1,71 @@
+#include "L3G4200D.h"
+
+L3G4200D::L3G4200D(PinName sda, PinName scl) : I2C_Sensor(sda, scl, L3G4200D_I2C_ADDRESS)
+{
+    // Turns on the L3G4200D's gyro and places it in normal mode.
+    // Normal power mode, all axes enabled (for detailed info see datasheet)
+    
+    //writeRegister(L3G4200D_CTRL_REG2, 0x05);               // control filter
+    writeRegister(L3G4200D_CTRL_REG2, 0x00);            // highpass filter disabled
+    writeRegister(L3G4200D_CTRL_REG3, 0x00);
+    writeRegister(L3G4200D_CTRL_REG4, 0x20);            // sets acuracy to 2000 dps (degree per second)
+    
+    writeRegister(L3G4200D_REFERENCE, 0x00);
+    //writeRegister(L3G4200D_STATUS_REG, 0x0F);
+    
+    writeRegister(L3G4200D_INT1_THS_XH, 0x2C); // TODO: WTF??
+    writeRegister(L3G4200D_INT1_THS_XL, 0xA4);
+    writeRegister(L3G4200D_INT1_THS_YH, 0x2C);
+    writeRegister(L3G4200D_INT1_THS_YL, 0xA4);
+    writeRegister(L3G4200D_INT1_THS_ZH, 0x2C);
+    writeRegister(L3G4200D_INT1_THS_ZL, 0xA4);
+    //writeRegister(L3G4200D_INT1_DURATION, 0x00);
+    
+    writeRegister(L3G4200D_CTRL_REG5, 0x00);            // deactivates the filters (only use one of these options)
+    //writeRegister(L3G4200D_CTRL_REG5, 0x12);          // activates both high and low pass filters
+    //writeRegister(L3G4200D_CTRL_REG5, 0x01);          // activates high pass filter
+    
+    writeRegister(L3G4200D_CTRL_REG1, 0x0F);            // starts Gyro measurement
+    
+    //calibrate(50, 0.01);
+}
+
+void L3G4200D::read()
+{
+    readraw();                                          // read raw measurement data
+    
+    for (int i = 0; i < 3; i++)
+            data[i] = (raw[i] - offset[i])*0.07;               // subtract offset from calibration and multiply unit factor (datasheet s.10)
+}
+
+int L3G4200D::readTemp()
+{
+    return (short) readRegister(L3G4200D_OUT_TEMP);     // read the sensors register for the temperature
+}
+
+void L3G4200D::readraw()
+{
+    char buffer[6];                                     // 8-Bit pieces of axis data
+    
+    readMultiRegister(L3G4200D_OUT_X_L | (1 << 7), buffer, 6); // read axis registers using I2C   // TODO: why?!   | (1 << 7)
+    
+    raw[0] = (short) (buffer[1] << 8 | buffer[0]);     // join 8-Bit pieces to 16-bit short integers
+    raw[1] = (short) (buffer[3] << 8 | buffer[2]);
+    raw[2] = (short) (buffer[5] << 8 | buffer[4]);
+}
+
+void L3G4200D::calibrate(int times, float separation_time)
+{
+    // calibrate sensor with an average of count samples (result of calibration stored in offset[])
+    float calib[3] = {0,0,0};                           // temporary array for the sum of calibration measurement
+    
+    for (int i = 0; i < times; i++) {                   // read 'times' times the data in a very short time
+        readraw();
+        for (int j = 0; j < 3; j++)
+            calib[j] += raw[j];
+        wait(separation_time);
+    }
+    
+    for (int i = 0; i < 3; i++)
+        offset[i] = calib[i]/times;                     // take the average of the calibration measurements
+}
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