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Rev | Author | Line No. | Line |
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1993 | - | 1 | /* |
2 | * HMC.cpp - Interface a Honeywell HMC5843 magnetometer to an AVR via i2c |
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3 | * Version 0.1 - http://www.timzaman.com/ |
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4 | * Copyright (c) 2011 Tim Zaman |
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5 | * All rights reserved. |
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6 | * |
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7 | * Redistribution and use in source and binary forms, with or without |
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8 | * modification, are permitted provided that the following conditions |
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9 | * are met: |
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10 | * 1. Redistributions of source code must retain the above copyright |
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11 | * notice, this list of conditions and the following disclaimer. |
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12 | * 2. Redistributions in binary form must reproduce the above copyright |
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13 | * notice, this list of conditions and the following disclaimer in the |
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14 | * documentation and/or other materials provided with the distribution. |
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15 | * |
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16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS |
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17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
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18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
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19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
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20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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26 | * POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
29 | #include "HMC.h" |
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30 | #include "WProgram.h" |
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31 | #include <Wire.h> |
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32 | |||
33 | /* PUBLIC METHODS */ |
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34 | |||
35 | HMC5843::HMC5843() |
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36 | { |
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37 | } |
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38 | |||
39 | void HMC5843::init() |
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40 | { |
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41 | } |
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42 | |||
43 | // This can be called at 100ms intervals to get new data |
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44 | void HMC5843::getValues(int *x, int *y, int *z) |
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45 | { |
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46 | Wire.begin(); //Initiate the Wire library and join the I2C bus as a master |
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47 | int regb=0x01; |
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48 | int regbdata=0x40; |
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49 | int outputData[6]; |
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50 | int i; |
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51 | double angle; |
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52 | |||
53 | |||
54 | Wire.beginTransmission(HMC5883_WriteAddress); |
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55 | Wire.send(regb); |
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56 | Wire.send(regbdata); |
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57 | Wire.endTransmission(); |
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58 | |||
59 | delay(1000); |
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60 | Wire.beginTransmission(HMC5883_WriteAddress); //Initiate a transmission with HMC5883 (Write address). |
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61 | Wire.send(HMC5883_ModeRegisterAddress); //Place the Mode Register Address in send-buffer. |
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62 | Wire.send(HMC5883_ContinuousModeCommand); //Place the command for Continuous operation Mode in send-buffer. |
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63 | Wire.endTransmission(); //Send the send-buffer to HMC5883 and end the I2C transmission. |
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64 | delay(100); |
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65 | |||
66 | |||
67 | Wire.beginTransmission(HMC5883_WriteAddress); //Initiate a transmission with HMC5883 (Write address). |
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68 | Wire.requestFrom(HMC5883_WriteAddress,6); //Request 6 bytes of data from the address specified. |
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69 | |||
70 | delay(500); |
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71 | |||
72 | |||
73 | //Read the value of magnetic components X,Y and Z |
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74 | |||
75 | if(6 <= Wire.available()) // If the number of bytes available for reading be <=6. |
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76 | { |
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77 | for(i=0;i<6;i++) |
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78 | { |
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79 | outputData[i]=Wire.receive(); //Store the data in outputData buffer |
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80 | } |
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81 | } |
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82 | |||
83 | *x=outputData[0] << 8 | outputData[1]; //Combine MSB and LSB of X Data output register |
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84 | *z=outputData[2] << 8 | outputData[3]; //Combine MSB and LSB of Z Data output register |
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85 | *y=outputData[4] << 8 | outputData[5]; //Combine MSB and LSB of Y Data output register |
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86 | } |
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87 | |||
88 | void HMC5843::getAngle(int *a) |
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89 | { |
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90 | int fx,fy,fz; |
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91 | getValues(&fx,&fy,&fz); |
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92 | *a= atan((double)fy/(double)fx)*(360/PI); // angle in degrees |
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93 | } |
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94 | |||
95 | |||
96 | |||
97 | // Set the default object |
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98 | HMC5843 HMC = HMC5843(); |
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99 | |||
100 | |||
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108 |