Arduino学习笔记A3 - Arduino连接HMC5883L三轴电子罗盘传感器
Arduino连接HMC5883L三轴电子罗盘传感器用途：测量地磁方向，测量物体静止时候的方向，测量传感器周围磁力线的方向。注意，测量地磁时候容易受到周围磁场影响，
主芯片HMC5883三轴磁阻传感器特点（抄自网上）：
1，数字量输出：I2C数字量输出接口，设计使用非常方便。
2，尺寸小: 3x3x0.9mm LCC封装，适合大规模量产使用。
3，精度高：1－2度，内置12位A/D,OFFSET, SET/RESET 电路，不会出现磁饱和现象，不会有累加误差。
4，支持自动校准程序，简化使用步骤，终端产品使用非常方便。
5，内置自测试电路，方便量产测试，无需增加额外昂贵的测试设备。
6，功耗低：供电电压1.8V, 功耗睡眠模式-2.5uA 测量模式-0.6mA
连接方法：
只要连接VCC，GND，SDA，SCL四条线。[*]Arduino GND -> HMC5883L GND[*]Arduino 3.3V -> HMC5883L VCC[*]Arduino A4 (SDA) -> HMC5883L SDA[*]Arduino A5 (SCL) -> HMC5883L SCL
(注意，接线是A4，A5，不是D4,D5)
程序编写：[*]下载HMC5883L库文件。下载地址：http://soft2.wmzhe.com/download/AnsifaArduino/HMC5883L.zip[*]解压HMC5883L库文件到arduino文件夹：arduino-0022\libraries下面。[*]编写以下程序，下载下面测试程序到arduino：
#include <Wire.h>
#include <HMC5883L.h>
HMC5883L compass;
void setup()
{
Serial.begin(9600);
Wire.begin();
compass = HMC5883L();
compass.SetScale(1.3);
compass.SetMeasurementMode(Measurement_Continuous);
}
void loop()
{
MagnetometerRaw raw = compass.ReadRawAxis();
MagnetometerScaled scaled = compass.ReadScaledAxis();
float xHeading = atan2(scaled.YAxis, scaled.XAxis);
float yHeading = atan2(scaled.ZAxis, scaled.XAxis);
float zHeading = atan2(scaled.ZAxis, scaled.YAxis);
if(xHeading < 0) xHeading += 2*PI;
if(xHeading > 2*PI) xHeading -= 2*PI;
if(yHeading < 0) yHeading += 2*PI;
if(yHeading > 2*PI) yHeading -= 2*PI;
if(zHeading < 0) zHeading += 2*PI;
if(zHeading > 2*PI) zHeading -= 2*PI;
float xDegrees = xHeading * 180/M_PI;
float yDegrees = yHeading * 180/M_PI;
float zDegrees = zHeading * 180/M_PI;
Serial.print(xDegrees);
Serial.print(",");
Serial.print(yDegrees);
Serial.print(",");
Serial.print(zDegrees);
Serial.println(";");
delay(100);
}
打开Arduino串口监视器即可看到结果（X平面角度，Y平面角度，Z平面角度）：
我按照上面的做了，为什么还是出错啊，求大神解答：
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp:23:23: error: WProgram.h: No such file or directory
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp: In member function 'void HMC5883L::Write(int, int)':
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp:110: error: 'class TwoWire' has no member named 'send'
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp:111: error: 'class TwoWire' has no member named 'send'
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp: In member function 'uint8_t* HMC5883L::Read(int, int)':
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp:118: error: 'class TwoWire' has no member named 'send'
F:\arduino\arduino-1.0-windows\arduino-1.0\libraries\HMC5883L\HMC5883L.cpp:129: error: 'class TwoWire' has no member named 'receive'
LZ好啊，我想问问如果我用的是HMC5843 ，应该还是一样的吧，就稍微改改就好了。。。
还有就是 if(xHeading < 0) xHeading += 2*PI;
if(xHeading > 2*PI) xHeading -= 2*PI;
if(yHeading < 0) yHeading += 2*PI;
if(yHeading > 2*PI) yHeading -= 2*PI;
if(zHeading < 0) zHeading += 2*PI;
if(zHeading > 2*PI) zHeading -= 2*PI;
这一段是不是把，x,y,z局限于一定的范围呢。。。。新人，求指教。。。多些LZ了 本帖最后由 ck59505 于 2011-10-20 15:43 编辑
ck59505 发表于 2011-10-19 22:08 static/image/common/back.gif
LZ好啊，我想问问如果我用的是HMC5843 ，应该还是一样的吧，就稍微改改就好了。。。
还有就是 if(xHea ...
哦，谢谢啦，还有我弱弱的问问。。。PI表示的是Arduino从传感器的来的数据吗，随着物体的移动，传来的PI值就不相同
额。。还是说是 π。。。 ck59505 发表于 2011-10-20 15:32 static/image/common/back.gif
哦，谢谢啦，还有我弱弱的问问。。。PI表示的是Arduino从传感器的来的数据吗，随着物体的移动，传来的P ...
PI是圆周率，其实这个库文件已经把能做的都做了，直接读就行，这一大坨代码无非是变变数据的格式 好东西，但是不知道这些数字是怎么分析的呢？
试问一下上面的模块和你使用的模块有什么区别吗？因为上面只有4个接口，而且没有针脚，要自己焊接挺麻烦的。 树·水·风 发表于 2012-3-7 16:15 static/image/common/back.gif
试问一下上面的模块和你使用的模块有什么区别吗？因为上面只有4个接口，而且没有针脚，要自己焊接挺麻烦的 ...
这种模块，只能3.3V供电，没有上拉电阻，所以连接arduino板子，上拉电阻需要手工接。其他没区别 弘毅 发表于 2012-3-7 17:50 static/image/common/back.gif
这种模块，只能3.3V供电，没有上拉电阻，所以连接arduino板子，上拉电阻需要手工接。其他没区别
哦，谢谢。我在淘宝上搜，有引脚的要贵很多，自己又没有焊接的经验，有点囧啊 本帖最后由 Randy 于 2012-4-28 11:49 编辑
最近在玩这个东西，刚刚测试了一下。我也来提供一下测出地磁场角度的程序！/*
HMC5883L_Example.pde - Example sketch for integration with an HMC5883L triple axis magnetomerwe.
Copyright (C) 2011 Love Electronics (loveelectronics.co.uk)
This program is free software: you can redistribute it and/or modify
it under the terms of the version 3 GNU General Public License as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program.If not, see <http://www.gnu.org/licenses/>.
*/
// 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.begin(9600);
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(compass.GetErrorText(error));
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.
Serial.println(compass.GetErrorText(error));
}
// 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: http://www.magnetic-declination.com/
// 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("Raw:\t");
Serial.print(raw.XAxis);
Serial.print(" ");
Serial.print(raw.YAxis);
Serial.print(" ");
Serial.print(raw.ZAxis);
Serial.print(" \tScaled:\t");
Serial.print(scaled.XAxis);
Serial.print(" ");
Serial.print(scaled.YAxis);
Serial.print(" ");
Serial.print(scaled.ZAxis);
Serial.print(" \tHeading:\t");
Serial.print(heading);
Serial.print(" Radians \t");
Serial.print(headingDegrees);
Serial.println(" Degrees \t");
}结果是这样的，问了HEAVEN的意思！
下面我又测了另外一个的结果，感觉奇怪，楼主懂什么原因？
树·水·风 发表于 2012-3-7 19:08 static/image/common/back.gif
哦，谢谢。我在淘宝上搜，有引脚的要贵很多，自己又没有焊接的经验，有点囧啊
焊接这几个针非常的简单，慢慢来！ 树·水·风 发表于 2012-3-7 19:08 static/image/common/back.gif
哦，谢谢。我在淘宝上搜，有引脚的要贵很多，自己又没有焊接的经验，有点囧啊
不用焊，找个粗的排针，插进去就好，一般过孔都会有镀层。排针插进去和焊接差不读牢固，电信号也非常好（毕竟镀金层的导电能力还是很不错的） 楼主的代码用了，很爽，呵呵
纠结了3天了，就是为了测试新买的10轴模块的好坏
之前用MWC代码测试之后唯独就是HMC5883L的读数不正常，经过这个库文件和楼主的代码，测试很好，呵呵 本帖最后由 darkorigin 于 2012-6-1 17:19 编辑
弘毅 发表于 2012-3-7 17:50 static/image/common/back.gif
这种模块，只能3.3V供电，没有上拉电阻，所以连接arduino板子，上拉电阻需要手工接。其他没区别
arduino不是自带了3.3v的口么？VCC接上去可以不？
另外， 感谢鸟版，感谢管理员弘毅大哥，感谢黑马版主，嘿嘿，最近讨教的东西太多了，你们的代码我也是一遍接一遍的“剽窃”。。。慢慢消化吧，呵呵，感谢能从你们这里学到东西嘿嘿！ darkorigin 发表于 2012-6-1 17:16 static/image/common/back.gif
arduino不是自带了3.3v的口么？VCC接上去可以不？
另外， 感谢鸟版，感谢管理员弘毅大哥，感谢黑马版 ...
可以的，arduino板子上的3V3就是一好NCP1117转换出来所得的电压！可以直接使用！ 用HMC5883L读数结果不正常，误差很大。就是手动偏转90读的话，读数变化不是90度，有时候是120度，也有的时候是140度，非常诡异，大家有没有遇到过类似的情况？