Arduino Uno 连接 HMC5883L 磁场传感器模块

Arduino Uno 连接 HMC5883L 磁场传感器模块



@Date: 2013/03/05
#include <Wire.h>
#include <HMC5883L.h>

HMC5883L compass; //@声明 HMC5883L 对象

void setup()
    Wire.begin(); //@启动 Wire
    compass = HMC5883L(); //@实例化 HMC5883L 对象
    setupHMC5883L(); //@调用后面的 setupHMC5883L 函数,设置 HMC5883L 对象

void loop()
    float heading = getHeading(); //@声明浮点数变量 heading
    Serial.println(heading); //@串口打印输出 heading 的值
    delay(100); //@延时100毫秒

void setupHMC5883L()
    //@配置 HMC5883L 对象,检查I2C是否返回错误代码
    int error;
    error = compass.SetScale(1.3); //@设置放大比率
    if(error != 0) Serial.println(compass.GetErrorText(error)); //@检查错误,如有则串口输出该错误
    error = compass.SetMeasurementMode(Measurement_Continuous); //@设置测量模式.
    if(error != 0) Serial.println(compass.GetErrorText(error)); //@检查错误,如有则串口输出该错误

float getHeading()
    MagnetometerScaled scaled = compass.ReadScaledAxis(); //@格式化
    float heading = atan2(scaled.YAxis, scaled.XAxis);

    if(heading < 0) heading += 2*PI;
    if(heading > 2*PI) heading -= 2*PI;

    return heading * RAD_TO_DEG; //@弧度转换为角度



// Reference the I2C Library
#include <Wire.h>
// Reference the HMC5883L Compass Library
#include <HMC5883L.h>

// Store our compass as a variable.
HMC5883L compass;
// Record any errors that may occur in the compass.
int error = 0;

// Out setup routine, here we will configure the microcontroller and compass.
void setup()
// Initialize the serial port.

Serial.println("Starting the I2C interface.");
Wire.begin(); // Start the I2C interface.

Serial.println("Constructing new HMC5883L");
compass = HMC5883L(); // Construct a new HMC5883 compass.

Serial.println("Setting scale to +/- 1.3 Ga");
error = compass.SetScale(1.3); // Set the scale of the compass.
if(error != 0) // If there is an error, print it out.

Serial.println("Setting measurement mode to continous.");
error = compass.SetMeasurementMode(Measurement_Continuous); // Set the measurement mode to Continuous
if(error != 0) // If there is an error, print it out.

// Our main program loop.
void loop()
// Retrive the raw values from the compass (not scaled).
MagnetometerRaw raw = compass.ReadRawAxis();
// Retrived the scaled values from the compass (scaled to the configured scale).
MagnetometerScaled scaled = compass.ReadScaledAxis();

// Values are accessed like so:
int MilliGauss_OnThe_XAxis = scaled.XAxis;// (or YAxis, or ZAxis)

// Calculate heading when the magnetometer is level, then correct for signs of axis.
float heading = atan2(scaled.YAxis, scaled.XAxis);

// Once you have your heading, you must then add your 'Declination Angle', which is the 'Error' of the magnetic field in your location.
// Find yours here:
// Mine is: 2� 37' W, which is 2.617 Degrees, or (which we need) 0.0456752665 radians, I will use 0.0457
// If you cannot find your Declination, comment out these two lines, your compass will be slightly off.
float declinationAngle = 0.0457;
heading += declinationAngle;

// Correct for when signs are reversed.
if(heading < 0)
  heading += 2*PI;

// Check for wrap due to addition of declination.
if(heading > 2*PI)
  heading -= 2*PI;

// Convert radians to degrees for readability.
float headingDegrees = heading * 180/M_PI;

// Output the data via the serial port.
Output(raw, scaled, heading, headingDegrees);

// Normally we would delay the application by 66ms to allow the loop
// to run at 15Hz (default bandwidth for the HMC5883L).
// However since we have a long serial out (104ms at 9600) we will let
// it run at its natural speed.
// delay(66);

// Output the data down the serial port.
void Output(MagnetometerRaw raw, MagnetometerScaled scaled, float heading, float headingDegrees)
Serial.print("  "); 
Serial.print("  "); 
Serial.print("  \tScaled:\t");

Serial.print("  "); 
Serial.print("  "); 

Serial.print("  \tHeading:\t");
Serial.print(" Radians  \t");
Serial.println(" Degrees  \t");