Diff: main.cpp

Revision:

0:26bfff579f01

Child:

1:d45fc466a46e

diff -r 000000000000 -r 26bfff579f01 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu May 16 22:11:33 2013 +0000
@@ -0,0 +1,282 @@
+#include "mbed.h"
+#include "math.h"
+
+//PwmOut r (LED_RED);
+//PwmOut g (LED_GREEN);
+//PwmOut b (LED_BLUE);
+
+
+
+#define MAG_ADDR 0x1D
+// (0x0E << 1)
+//0x1D
+
+// define register values
+#define MAG_DR_STATUS 0x00
+#define MAG_OUT_X_MSB 0x01
+#define MAG_OUT_X_LSB 0x02
+#define MAG_OUT_Y_MSB 0x03
+#define MAG_OUT_Y_LSB 0x04
+#define MAG_OUT_Z_MSB 0x05
+#define MAG_OUT_Z_LSB 0x06
+#define MAG_WHO_AM_I  0x07
+#define MAG_SYSMOD    0x08
+#define MAG_OFF_X_MSB 0x09
+#define MAG_OFF_X_LSB 0x0A
+#define MAG_OFF_Y_MSB 0x0B
+#define MAG_OFF_Y_LSB 0x0C
+#define MAG_OFF_Z_MSB 0x0D
+#define MAG_OFF_Z_LSB 0x0E
+#define MAG_DIE_TEMP  0x0F
+#define MAG_CTRL_REG1 0x10
+#define MAG_CTRL_REG2 0x11
+
+// what should WHO_AM_I return?
+#define MAG_3110_WHO_AM_I_VALUE 0xC4
+
+
+// Fields in registers
+// CTRL_REG1: dr2,dr1,dr0  os1,os0  fr tm ac
+
+// Sampling rate from 80Hz down to 0.625Hz
+#define MAG_3110_SAMPLE80 0
+#define MAG_3110_SAMPLE40 0x20
+#define MAG_3110_SAMPLE20 0x40
+#define MAG_3110_SAMPLE10 0x60
+#define MAG_3110_SAMPLE5 0x80
+#define MAG_3110_SAMPLE2_5 0xA0
+#define MAG_3110_SAMPLE1_25 0xC0
+#define MAG_3110_SAMPLE0_625 0xE0
+
+// How many samples to average (lowers data rate)
+#define MAG_3110_OVERSAMPLE1 0
+#define MAG_3110_OVERSAMPLE2 0x08
+#define MAG_3110_OVERSAMPLE3 0x10
+#define MAG_3110_OVERSAMPLE4 0x18
+
+// read only 1 byte per axis
+#define MAG_3110_FASTREAD 0x04
+// do one measurement (even if in standby mode)
+#define MAG_3110_TRIGGER 0x02
+// put in active mode
+#define MAG_3110_ACTIVE 0x01
+
+// CTRL_REG2: AUTO_MRST_EN  _ RAW MAG_RST _ _ _ _ _
+// reset sensor after each reading
+#define MAG_3110_AUTO_MRST_EN 0x80
+// don't subtract user offsets
+#define MAG_3110_RAW 0x20
+// reset magnetic sensor after too-large field
+#define MAG_3110_MAG_RST 0x10
+
+// DR_STATUS Register ZYXOW ZOW YOW XOW ZYXDR ZDR YDR XDR
+#define MAG_3110_ZYXDR  0x08
+
+
+//0x0E //7-bit address for the MAG3110, doesn't change
+
+DigitalOut myled(PTB10);
+DigitalOut redLed(LED_RED);
+DigitalOut greenLed(LED_GREEN);
+DigitalOut blueLed(LED_BLUE);
+
+I2C i2c(PTE0, PTE1);
+
+int avgX, avgY, newX, tempXmin, tempXmax, newY, tempYmin, tempYmax;
+struct settings_t {
+    long maxX, minX, maxY, minY;
+}
+settings;
+
+const int addr = MAG_ADDR;
+
+// Read a single byte form 8 bit register, return as int
+int readReg(char regAddr)
+{
+    char cmd[1];
+
+    cmd[0] = regAddr;
+    i2c.write(addr, cmd, 1);
+
+    cmd[0] = 0x00;
+    i2c.read(addr, 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 readVal(char regAddr)
+{
+    char cmd[2];
+
+    cmd[0] = regAddr;
+    i2c.write(addr, cmd, 1);
+
+    cmd[0] = 0x00;
+    cmd[1] = 0x00;
+    i2c.read(addr, cmd, 2);
+    return (int)( (cmd[1]|(cmd[0] << 8))); //concatenate the MSB and LSB
+}
+
+#define PI 3.14159265359
+
+
+void calXY() //magnetometer calibration: finding max and min of X, Y axis
+{
+    int tempXmax, tempXmin, tempYmax, tempYmin, newX, newY;
+    redLed = 0;
+//    lcd.setCursor(0,1);
+//    lcd.print(“Rotate the car “);
+//    delay(1000);
+//    lcd.setCursor(0,1);
+//    lcd.print(“and press button”);
+//    delay(1000);
+//    lcd.setCursor(0,1);
+//    lcd.print(“Now, begin! “);
+//    delay(500);
+    tempXmax = tempXmin = readVal(MAG_OUT_X_MSB);
+    tempYmax = tempYmin = readVal(MAG_OUT_Y_MSB);
+    int changeCount = 10000;
+    bool change = false;
+    while(changeCount) {   // digitalRead(10) == LOW) {
+//    for(int x=0; x<100000; x++); {
+        //newX = readx();
+        //newY = ready();
+        newX = readVal(MAG_OUT_X_MSB);
+        newY = readVal(MAG_OUT_Y_MSB);
+        if (newX > tempXmax) {
+            tempXmax = newX;
+            change = true;
+        }
+        if (newX < tempXmin) {
+            tempXmin = newX;
+            change = true;
+        }
+        if (newY > tempYmax) {
+            tempYmax = newY;
+            change = true;
+        }
+        if (newY < tempYmin) {
+            tempYmin = newY;
+            change = true;
+        }
+        if( change )
+            change = false;
+        else
+            changeCount--;
+//        printf("X max %d min %d, Y max %d min %d\n",tempXmax, tempXmin, tempYmax, tempYmin);
+    }
+    settings.maxX = tempXmax;
+    settings.minX = tempXmin;
+    settings.maxY = tempYmax;
+    settings.minY = tempYmin;
+    //X max 65173 min 64850, Y max 490 min 141
+
+//store new X, Y values in the EEPROM
+//    eeprom_write_block((const void*)&settings, (void*)0, sizeof(settings));
+
+    avgX=(settings.maxX+settings.minX)/2;
+    avgY=(settings.maxY+settings.minY)/2;
+
+    redLed = 1;
+//    lcd.setCursor(0,1);
+//    lcd.print(“Calibration done”);
+    //delay(3000);
+//    lcd.setCursor(0,1);
+//    lcd.print(” “);
+
+}
+
+int main()
+{
+    char cmd[2];
+//    r.period(0.001);
+//    g.period(0.001);
+//    b.period(0.001);
+
+    printf("MAG3110 Test\n");
+
+    redLed = 1;
+    greenLed = 1;
+    blueLed = 1;
+    
+    cmd[0] = MAG_CTRL_REG2;
+    cmd[1] = 0x80;
+    i2c.write(addr, cmd, 2);
+
+//    wait(0.1);
+    cmd[0] = MAG_CTRL_REG1;
+    cmd[1] = MAG_3110_SAMPLE80+MAG_3110_OVERSAMPLE2+MAG_3110_ACTIVE; // 0x91;
+    i2c.write(addr, cmd, 2);
+
+    // Get some values
+    printf("DR_STATUS %X\n", readReg( MAG_DR_STATUS ));
+    printf("WHO_AM_I %X\n", readReg( MAG_WHO_AM_I ));
+    printf("SYSMOD %X\n", readReg( MAG_SYSMOD ));
+    printf("DIE_TEMP %d\n", readReg( MAG_DIE_TEMP ));
+
+    printf("OFF_X %d\n", readVal( MAG_OFF_X_MSB ));
+    printf("OFF_Y %d\n", readVal( MAG_OFF_Y_MSB ));
+    printf("OFF_Z %d\n", readVal( MAG_OFF_Z_MSB ));
+
+    printf("CTRL_REG1 %X\n", readReg( MAG_CTRL_REG1 ));
+    printf("CTRL_REG2 %X\n", readReg( MAG_CTRL_REG2 ));
+
+//    r = 1;
+//    g = 0;
+//    b = 0;
+    settings.maxX = 65173;
+    settings.minX = 64850;
+    settings.maxY = 490;
+    settings.minY = 141;
+    //X max 65173 min 64850, Y max 490 min 141
+    avgX=(settings.maxX+settings.minX)/2;
+    avgY=(settings.maxY+settings.minY)/2;
+    printf("avgX = %d, avgY = %d\n", avgX, avgY);
+
+//    avgX = 0;
+//    avgY = 0;
+
+    printf("calibrate\n");
+    calXY();
+    printf("....Finished\n");
+    printf("avgX = %d, avgY = %d\n", avgX, avgY);
+
+ //   greenLed = 1;
+    redLed = 1;
+    greenLed = 1;
+    blueLed = 1;
+    
+    while (1) {
+        wait(0.5);
+        int xVal = readVal(MAG_OUT_X_MSB);
+        int yVal = readVal(MAG_OUT_Y_MSB);
+        float heading = (atan2((double)(yVal-avgY),(double)(xVal-avgX)))*180/PI;
+//        float heading = (atan2((double)(xVal-avgX),(double)(yVal-avgY)))*180/PI;
+
+        if (abs(heading) <= 22.5) { printf("N\n"); greenLed = 0; } else greenLed = 1;
+        if (abs(heading) >= 157.5) printf("S\n");
+        if (heading >= 67.5 && heading <= 112.5) printf("E \n");
+        if (heading <= -67.5 && heading >= -112.5) printf("W \n");
+        if (heading > 22.5 && heading < 67.5) printf("NE\n");
+        if (heading < -22.5 && heading > -67.5) printf("NW\n");
+        if (heading > 112.5 && heading < 157.5) printf("SE\n");
+        if (heading < -112.5 && heading > -157.5) printf("SW\n");
+
+        if (heading < 0) heading += 360.0;
+        printf("xVal - avgX = %d, yVal - avgY = %d  ", xVal-avgX, yVal-avgY);
+        printf("X = %d, Y = %d, Heading %f\n", xVal, yVal, heading);
+
+
+
+//        printf("2 byte: X = %d ", readVal( 0x01 ));
+//        printf(" Y = %d ", readVal( 0x03 ));
+//        printf(" Z = %d\n", readVal( 0x05 ));
+
+//        printf("1 byte: X = %d ", readx());
+//        printf(" Y = %d ", ready());
+//        printf(" Z = %d\n", readz());
+    }
+}