Revision 1:dc730a26cdc2, committed 2012-10-30

Comitter:

tylerjw

Date:

Tue Oct 30 23:47:14 2012 +0000

Parent:

0:ac2f55940442

Child:

2:d7e66940541d

Commit message:

HMC5883L prof of concept

Changed in this revision

--- a/main.cpp	Tue Oct 30 17:30:03 2012 +0000
+++ b/main.cpp	Tue Oct 30 23:47:14 2012 +0000
@@ -8,23 +8,161 @@
  the temperature drift line.  Data will be logged to help determine the
  thermal drift line.
  See: http://mbed.org/users/gltest26/code/ITG3200/wiki/Thermal-Drift
+
+ The second versoin of this will test the HMC5883L 3 axis magnometer
 */
 
 #include "mbed.h"
-#include "ITG3200.h"
+//#include "ITG3200.h"
+
+// configuration register a
+#define AVG1_SAMPLES    0x00
+#define AVG2_SAMPLES    0x20
+#define AVG4_SAMPLES    0x80
+#define AVG8_SAMPLES    0xC0
+
+#define OUTPUT_RATE_0_75    0x00
+#define OUTPUT_RATE_1_5     0x04
+#define OUTPUT_RATE_3       0x08
+#define OUTPUT_RATE_7_5     0x0C
+#define OUTPUT_RATE_15      0x10
+#define OUTPUT_RATE_30      0x14
+#define OUTPUT_RATE_75      0x18
+
+#define NORMAL_MEASUREMENT  0x00
+#define POSITIVE_BIAS       0x01
+#define NEGATIVE_BIAS       0x02
+
+// mode register
+#define CONTINUOUS_MODE     0x00
+#define SINGLE_MODE         0x01
+#define IDLE_MODE           0x02
+
+// status register 
+#define LOCK        0x02
+#define READY       0x01
+
+char addr = 0x3D;
+
+I2C i2c_(p28, p27); // sda, scl
+
+void setConfigurationA(char,char,char);
+char getConfigurationA();
+void setConfigurationB(char);
+char getConfigurationB();
+void setMode(char);
+char getMode();
+void getXYZ(int*);
+char getStatus();
+
+void setConfigurationA(char averaged_samples = AVG1_SAMPLES, char output_rate = OUTPUT_RATE_15, char measurement_mode = NORMAL_MEASUREMENT)
+{
+    char cmd[2];
+    cmd[0] = 0x00; // register a address
+    cmd[1] = averaged_samples | output_rate | measurement_mode;
+    
+    i2c_.write(addr, cmd, 2);
+}
+
+char getConfigurationA()
+{
+    char cmd[2];
+    cmd[0] = 0x00; // register a address
+    i2c_.write(addr, cmd, 1, true);
+    i2c_.read(addr, &cmd[1], 1, false);
+    return cmd[1];
+}
+
+void setConfigurationB(char gain = 0x20) // default value 0x20
+{
+    char cmd[2];
+    cmd[0] = 0x01;
+    cmd[1] = gain;
+    
+    i2c_.write(addr, cmd, 2);
+}
+
+char getConfigurationB()
+{
+    char cmd[2];
+    cmd[0] = 0x01; // register b address
+    i2c_.write(addr, cmd, 1, true);
+    i2c_.read(addr, &cmd[1], 1, false);
+    return cmd[1];
+}
+
+void setMode(char mode = SINGLE_MODE)
+{
+    char cmd[2];
+    cmd[0] = 0x02; // mode register address
+    cmd[1] = mode;
+    i2c_.write(addr,cmd,2);
+}
+
+char getMode()
+{
+    char cmd[2];
+    cmd[0] = 0x02; // mode register address
+    i2c_.write(addr, cmd, 1, true);
+    i2c_.read(addr, &cmd[1], 1, false);
+    return cmd[1];
+}
+
+void getXYZ(int output[3])
+{
+    char cmd[2];
+    char data[6];
+    cmd[0] = 0x03; // starting point for reading
+    i2c_.write(addr, cmd, 1, true); // set the pointer to the start of x
+    i2c_.read(addr, data, 6, false);
+    
+    for(int i = 0; i < 3; i++) // fill the output variables
+        output[i] = (data[i*2] << 8) + data[i*2+1];
+}
+
+char getStatus()
+{
+    char cmd[2];
+    cmd[0] = 0x09; // status register address
+    i2c_.write(addr, cmd, 1, true);
+    i2c_.read(addr, &cmd[1], 1, false);
+    return cmd[1];
+}
 
 int main()
 {
-    DigitalOut myled(p24);
+    Serial pc(USBTX, USBRX);
+    
+    pc.baud(9600);
+    
+    int data[3];
+    
+    // configure
+    setConfigurationA(AVG8_SAMPLES); // 8 sample average, 15Hz, normal mode
+    setConfigurationB(); // default (0x20)
+    setMode(CONTINUOUS_MODE); // continuous sample mode
+    wait(0.006); // 6 milisecond pause to allow registers to fill up
+    
+    while(1)
+    {
+        getXYZ(data);
+        pc.printf("x: 0x%4x, y: 0x%4x, z: 0x%4x\r\n", data[0], data[1], data[2]);
+        wait(0.067);
+    }
+}
+
+/*
+void itg3200_test()
+{
+    DigitalOut myled(LED1);
     LocalFileSystem local("local");               // Create the local filesystem under the name "local"
     ITG3200 gyro(p28, p27); // sda, scl - gyro
-    //const float offset[3] = {99.53, -45.26, -29.53}; // taken from itg3200_05.xls curve fit
-    //const float slope[3] = {-0.95, 0.95, 0.47};
-    
-    //gyro.setCalibrationCurve(offset, slope);
-    //gyro.calibrate(1.0);
-    gyro.setLpBandwidth(LPFBW_5HZ);
-    
+    const float offset[3] = {99.5, -45.0, -29.7}; // taken from itg3200.xls curve fit test
+    const float slope[3] = {-1.05, 0.95, 0.47};
+
+    gyro.setCalibrationCurve(offset, slope);
+    gyro.setLpBandwidth(LPFBW_5HZ); // lowest rate low-pass filter
+
     Serial pc(USBTX, USBRX);
 
     pc.baud(9600);
@@ -38,11 +176,11 @@
 
     for(int i = 0; i < 120; i++) { // 120 seconds - 600 samples
         myled = 1;
-        gyro.calibrate(1.0);
-        //wait(0.5);
+        //gyro.calibrate(1.0);
+        wait(0.5);
         myled = 0;
-        //gyro.getGyroXYZ(gyro_readings, ITG3200::Calibration);
-        gyro.getOffset(gyro_readings);
+        gyro.getGyroXYZ(gyro_readings, ITG3200::Calibration);
+        //gyro.getOffset(gyro_readings);
         temperature = gyro.getTemperature();
         pc.printf("%3d,%f,%d,%d,%d\r\n",i,temperature,gyro_readings[0],gyro_readings[1],gyro_readings[2]);
         fprintf(fp, "%f,%d,%d,%d\r\n",temperature,gyro_readings[0],gyro_readings[1],gyro_readings[2]);
@@ -50,3 +188,4 @@
     fclose(fp);
     myled = 0;
 }
+*/
\ No newline at end of file