Diff: MAG3110.cpp.orig

Revision:

7:0f45239e157a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAG3110.cpp.orig	Fri May 09 18:01:36 2014 +0000
@@ -0,0 +1,118 @@
+
+#include "MAG3110.h"
+#include "mbed.h"
+
+/******************************************************************************
+ * Constructors
+ ******************************************************************************/
+MAG3110::MAG3110(PinName sda, PinName scl): _i2c(sda, scl),
+    _i2c_address(0x1D), _pc(NULL), _debug(false)
+{
+    begin();
+}
+
+MAG3110::MAG3110(PinName sda, PinName scl, Serial *pc): _i2c(sda, scl),
+    _i2c_address(0x1D), _pc(pc), _debug(true)
+{
+    begin();
+}
+
+void MAG3110::begin()
+{
+    char cmd[2];
+
+    cmd[0] = MAG_CTRL_REG2;
+    cmd[1] = 0x80;
+    _i2c.write(_i2c_address, cmd, 2);
+
+    cmd[0] = MAG_CTRL_REG1;
+    cmd[1] = MAG_3110_SAMPLE80+MAG_3110_OVERSAMPLE2+MAG_3110_ACTIVE;
+    _i2c.write(_i2c_address, cmd, 2);
+
+    // No adjustment initially
+    _avgX = 0;
+    _avgY = 0;
+}
+
+// Read a single byte form 8 bit register, return as int
+int MAG3110::readReg(char regAddr)
+{
+    char cmd[1];
+
+    cmd[0] = regAddr;
+    _i2c.write(_i2c_address, cmd, 1);
+
+    cmd[0] = 0x00;
+    _i2c.read(_i2c_address, cmd, 1);
+    return (int)( cmd[0]);
+}
+
+
+// read a register per, pass first reg value, reading 2 bytes increments register
+// Reads MSB first then LSB
+int MAG3110::readVal(char regAddr)
+{
+    char cmd[2];
+
+    cmd[0] = regAddr;
+    _i2c.write(_i2c_address, cmd, 1);
+
+    cmd[0] = 0x00;
+    cmd[1] = 0x00;
+    _i2c.read(_i2c_address, cmd, 2);
+    return (int)( (cmd[1]|(cmd[0] << 8))); //concatenate the MSB and LSB
+}
+
+
+float MAG3110::getHeading()
+{
+    int xVal = readVal(MAG_OUT_X_MSB);
+    int yVal = readVal(MAG_OUT_Y_MSB);
+    return (atan2((double)(yVal - _avgY),(double)(xVal - _avgX)))*180/PI;
+}
+
+void MAG3110::getValues(int *xVal, int *yVal, int *zVal)
+{
+    *xVal = readVal(MAG_OUT_X_MSB);
+    *yVal = readVal(MAG_OUT_Y_MSB);
+    *zVal = readVal(MAG_OUT_Z_MSB);
+}
+
+
+void MAG3110::setCalibration(int minX, int maxX, int minY, int maxY )
+{
+    _avgX=(maxX+minX)/2;
+    _avgY=(maxY+minY)/2;
+}
+
+
+
+void MAG3110::calXY(PinName pin, int activeValue )
+{
+    DigitalIn calPin(pin);
+    int tempXmax, tempXmin, tempYmax, tempYmin, newX, newY;
+
+
+    // Wait for Button Press and Release before beginning calibration
+    while(calPin != activeValue) {}
+    while(calPin == activeValue) {}
+
+
+    // Read initial values of magnetomoter - read it here to create a slight delay for calPin to settle
+    tempXmax = tempXmin = readVal(MAG_OUT_X_MSB);
+    tempYmax = tempYmin = readVal(MAG_OUT_Y_MSB);
+
+    // Update min and max values until calPin asserted again
+    while(calPin != activeValue) {
+        newX = readVal(MAG_OUT_X_MSB);
+        newY = readVal(MAG_OUT_Y_MSB);
+        if (newX > tempXmax) tempXmax = newX;
+        if (newX < tempXmin) tempXmin = newX;
+        if (newY > tempYmax) tempYmax = newY;
+        if (newY < tempYmin) tempYmin = newY;
+    }
+
+    setCalibration( tempXmin, tempXmax, tempYmin, tempYmax );
+
+}
+