Wiimote.cpp

00001 /* Copyright (c) 2011, mbed
00002  * 
00003  * Permission is hereby granted, free of charge, to any person obtaining a copy
00004  * of this software and associated documentation files (the "Software"), to deal
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00007  * copies of the Software, and to permit persons to whom the Software is
00008  * furnished to do so, subject to the following conditions:
00009  *  
00010  * The above copyright notice and this permission notice shall be included in
00011  * all copies or substantial portions of the Software.
00012  *  
00013  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00014  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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00019  * THE SOFTWARE.
00020  */
00021 
00022 // Simple decode class for Wii Remote data
00023 
00024 #include "Wiimote.h"
00025 
00026 // Wii Report Formats: 
00027 //  * http://wiibrew.org/wiki/Wiimote#0x37:_Core_Buttons_and_Accelerometer_with_10_IR_bytes_and_6_Extension_Bytes
00028 //  * http://wiki.wiimoteproject.com/Reports#0x37_BTN_.2B_XLR_.2B_IR_.2B_6_EXT
00029 
00030 // Input Report 0x37:
00031 // 
00032 // 0 [ ?    |    X(1:0)   | PLUS  | UP | DOWN | RIGHT | LEFT ]
00033 // 1 [ HOME | Z(1) | Y(1) | MINUS |  A |   B  |  ONE  |  TWO ]
00034 // 2 [                        X(9:2)                         ]
00035 // 3 [                        Y(9:2)                         ]
00036 // 4 [                        Z(9:2)                         ]
00037 //
00038 
00039 #include <stdio.h>
00040 #include <math.h>
00041 
00042 #define WII_ZERO 0x206
00043 #define WII_1G   0x6A
00044 
00045 void Wiimote::decode(char* data) {
00046 
00047     // read buttons
00048     left  = (data[0] >> 0) & 0x1;
00049     right = (data[0] >> 1) & 0x1;
00050     down  = (data[0] >> 2) & 0x1;
00051     up    = (data[0] >> 3) & 0x1;
00052     plus  = (data[0] >> 4) & 0x1;
00053     two   = (data[1] >> 0) & 0x1;
00054     one   = (data[1] >> 1) & 0x1;
00055     b     = (data[1] >> 2) & 0x1;
00056     a     = (data[1] >> 3) & 0x1;
00057     minus = (data[1] >> 4) & 0x1;
00058     home  = (data[1] >> 7) & 0x1;
00059     
00060     // read accelerometers
00061     rawx = (data[2] << 2) | (data[0] & 0x60) >> 5;
00062     rawy = (data[3] << 2) | (data[1] & 0x20) >> 4;
00063     rawz = (data[4] << 2) | (data[1] & 0x40) >> 5;
00064 
00065     // calculate accelerometer gravity
00066     x = (float)((int)rawx - WII_ZERO) / (float)WII_1G;
00067     y = (float)((int)rawy - WII_ZERO) / (float)WII_1G;
00068     z = (float)((int)rawz - WII_ZERO) / (float)WII_1G;
00069 
00070     // calculate wheel angle    
00071     wheel = atan2(-y, -x) * (180.0 / 3.141592);
00072 } 
00073 
00074 void Wiimote::dump() {
00075     printf("%d%d%d%d%d%d%d%d%d%d%d %.3f %.3f %.3f %.2f\n", left, right, down, up, plus, two, one, b, a, minus, home, x, y, z, wheel);
00076 }
00077 
00078 
00079 // Accelerometer data
00080 //      y-
00081 //     +---+               +--+
00082 //     | + |               +  B
00083 //     | A |               A  |
00084 //     |   |               |  |
00085 // x+  |   |  x-       z+  |  |  z-
00086 //     | 1 |               1  |
00087 //     | 2 |               2  |
00088 //     +---+               +--+
00089 //      y+
00090 //
00091 // x+ 0x19B
00092 // x0 0x205
00093 // x- 0x26E
00094 //
00095 // y+ 0x19C   0x6A
00096 // y0 0x206
00097 // y- 0x26E   0x68
00098 //
00099 // z+ 0x19C 
00100 // z0 0x208
00101 // z- 0x26E