kashiko aoyama / QEI

r_test1_2017_10_11_Wed_A

Fork of QEI by Aaron Berk

QEI.h@1:8658787f9ec5, 2017-10-11 (annotated)

Committer:
shobonwarrior
Date:
Wed Oct 11 08:14:24 2017 +0000
Revision:
1:8658787f9ec5
Parent:
0:5c2ad81551aa 
r_test1_2017/10/11/Wed_A

Who changed what in which revision?

UserRevisionLine numberNew contents of line
aberk 0:5c2ad81551aa 1 /**
aberk 0:5c2ad81551aa 2 * @author Aaron Berk
aberk 0:5c2ad81551aa 3 *
aberk 0:5c2ad81551aa 4 * @section LICENSE
aberk 0:5c2ad81551aa 5 *
aberk 0:5c2ad81551aa 6 * Copyright (c) 2010 ARM Limited
aberk 0:5c2ad81551aa 7 *
aberk 0:5c2ad81551aa 8 * Permission is hereby granted, free of charge, to any person obtaining a copy
aberk 0:5c2ad81551aa 9 * of this software and associated documentation files (the "Software"), to deal
aberk 0:5c2ad81551aa 10 * in the Software without restriction, including without limitation the rights
aberk 0:5c2ad81551aa 11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
aberk 0:5c2ad81551aa 12 * copies of the Software, and to permit persons to whom the Software is
aberk 0:5c2ad81551aa 13 * furnished to do so, subject to the following conditions:
aberk 0:5c2ad81551aa 14 *
aberk 0:5c2ad81551aa 15 * The above copyright notice and this permission notice shall be included in
aberk 0:5c2ad81551aa 16 * all copies or substantial portions of the Software.
aberk 0:5c2ad81551aa 17 *
aberk 0:5c2ad81551aa 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
aberk 0:5c2ad81551aa 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
aberk 0:5c2ad81551aa 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
aberk 0:5c2ad81551aa 21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
aberk 0:5c2ad81551aa 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
aberk 0:5c2ad81551aa 23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
aberk 0:5c2ad81551aa 24 * THE SOFTWARE.
aberk 0:5c2ad81551aa 25 *
aberk 0:5c2ad81551aa 26 * @section DESCRIPTION
aberk 0:5c2ad81551aa 27 *
aberk 0:5c2ad81551aa 28 * Quadrature Encoder Interface.
aberk 0:5c2ad81551aa 29 *
aberk 0:5c2ad81551aa 30 * A quadrature encoder consists of two code tracks on a disc which are 90
aberk 0:5c2ad81551aa 31 * degrees out of phase. It can be used to determine how far a wheel has
aberk 0:5c2ad81551aa 32 * rotated, relative to a known starting position.
aberk 0:5c2ad81551aa 33 *
aberk 0:5c2ad81551aa 34 * Only one code track changes at a time leading to a more robust system than
aberk 0:5c2ad81551aa 35 * a single track, because any jitter around any edge won't cause a state
aberk 0:5c2ad81551aa 36 * change as the other track will remain constant.
aberk 0:5c2ad81551aa 37 *
aberk 0:5c2ad81551aa 38 * Encoders can be a homebrew affair, consisting of infrared emitters/receivers
aberk 0:5c2ad81551aa 39 * and paper code tracks consisting of alternating black and white sections;
aberk 0:5c2ad81551aa 40 * alternatively, complete disk and PCB emitter/receiver encoder systems can
aberk 0:5c2ad81551aa 41 * be bought, but the interface, regardless of implementation is the same.
aberk 0:5c2ad81551aa 42 *
aberk 0:5c2ad81551aa 43 * +-----+ +-----+ +-----+
aberk 0:5c2ad81551aa 44 * Channel A | ^ | | | | |
aberk 0:5c2ad81551aa 45 * ---+ ^ +-----+ +-----+ +-----
aberk 0:5c2ad81551aa 46 * ^ ^
aberk 0:5c2ad81551aa 47 * ^ +-----+ +-----+ +-----+
aberk 0:5c2ad81551aa 48 * Channel B ^ | | | | | |
aberk 0:5c2ad81551aa 49 * ------+ +-----+ +-----+ +-----
aberk 0:5c2ad81551aa 50 * ^ ^
aberk 0:5c2ad81551aa 51 * ^ ^
aberk 0:5c2ad81551aa 52 * 90deg
aberk 0:5c2ad81551aa 53 *
aberk 0:5c2ad81551aa 54 * The interface uses X2 encoding by default which calculates the pulse count
aberk 0:5c2ad81551aa 55 * based on reading the current state after each rising and falling edge of
aberk 0:5c2ad81551aa 56 * channel A.
aberk 0:5c2ad81551aa 57 *
aberk 0:5c2ad81551aa 58 * +-----+ +-----+ +-----+
aberk 0:5c2ad81551aa 59 * Channel A | | | | | |
aberk 0:5c2ad81551aa 60 * ---+ +-----+ +-----+ +-----
aberk 0:5c2ad81551aa 61 * ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 62 * ^ +-----+ ^ +-----+ ^ +-----+
aberk 0:5c2ad81551aa 63 * Channel B ^ | ^ | ^ | ^ | ^ | |
aberk 0:5c2ad81551aa 64 * ------+ ^ +-----+ ^ +-----+ +--
aberk 0:5c2ad81551aa 65 * ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 66 * ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 67 * Pulse count 0 1 2 3 4 5 ...
aberk 0:5c2ad81551aa 68 *
aberk 0:5c2ad81551aa 69 * This interface can also use X4 encoding which calculates the pulse count
aberk 0:5c2ad81551aa 70 * based on reading the current state after each rising and falling edge of
aberk 0:5c2ad81551aa 71 * either channel.
aberk 0:5c2ad81551aa 72 *
aberk 0:5c2ad81551aa 73 * +-----+ +-----+ +-----+
aberk 0:5c2ad81551aa 74 * Channel A | | | | | |
aberk 0:5c2ad81551aa 75 * ---+ +-----+ +-----+ +-----
aberk 0:5c2ad81551aa 76 * ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 77 * ^ +-----+ ^ +-----+ ^ +-----+
aberk 0:5c2ad81551aa 78 * Channel B ^ | ^ | ^ | ^ | ^ | |
aberk 0:5c2ad81551aa 79 * ------+ ^ +-----+ ^ +-----+ +--
aberk 0:5c2ad81551aa 80 * ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 81 * ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 82 * Pulse count 0 1 2 3 4 5 6 7 8 9 ...
aberk 0:5c2ad81551aa 83 *
aberk 0:5c2ad81551aa 84 * It defaults
aberk 0:5c2ad81551aa 85 *
aberk 0:5c2ad81551aa 86 * An optional index channel can be used which determines when a full
aberk 0:5c2ad81551aa 87 * revolution has occured.
aberk 0:5c2ad81551aa 88 *
aberk 0:5c2ad81551aa 89 * If a 4 pules per revolution encoder was used, with X4 encoding,
aberk 0:5c2ad81551aa 90 * the following would be observed.
aberk 0:5c2ad81551aa 91 *
aberk 0:5c2ad81551aa 92 * +-----+ +-----+ +-----+
aberk 0:5c2ad81551aa 93 * Channel A | | | | | |
aberk 0:5c2ad81551aa 94 * ---+ +-----+ +-----+ +-----
aberk 0:5c2ad81551aa 95 * ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 96 * ^ +-----+ ^ +-----+ ^ +-----+
aberk 0:5c2ad81551aa 97 * Channel B ^ | ^ | ^ | ^ | ^ | |
aberk 0:5c2ad81551aa 98 * ------+ ^ +-----+ ^ +-----+ +--
aberk 0:5c2ad81551aa 99 * ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 100 * ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 101 * ^ ^ ^ +--+ ^ ^ +--+ ^
aberk 0:5c2ad81551aa 102 * ^ ^ ^ | | ^ ^ | | ^
aberk 0:5c2ad81551aa 103 * Index ------------+ +--------+ +-----------
aberk 0:5c2ad81551aa 104 * ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
aberk 0:5c2ad81551aa 105 * Pulse count 0 1 2 3 4 5 6 7 8 9 ...
aberk 0:5c2ad81551aa 106 * Rev. count 0 1 2
aberk 0:5c2ad81551aa 107 *
aberk 0:5c2ad81551aa 108 * Rotational position in degrees can be calculated by:
aberk 0:5c2ad81551aa 109 *
aberk 0:5c2ad81551aa 110 * (pulse count / X * N) * 360
aberk 0:5c2ad81551aa 111 *
aberk 0:5c2ad81551aa 112 * Where X is the encoding type [e.g. X4 encoding => X=4], and N is the number
aberk 0:5c2ad81551aa 113 * of pulses per revolution.
aberk 0:5c2ad81551aa 114 *
aberk 0:5c2ad81551aa 115 * Linear position can be calculated by:
aberk 0:5c2ad81551aa 116 *
aberk 0:5c2ad81551aa 117 * (pulse count / X * N) * (1 / PPI)
aberk 0:5c2ad81551aa 118 *
aberk 0:5c2ad81551aa 119 * Where X is encoding type [e.g. X4 encoding => X=44], N is the number of
aberk 0:5c2ad81551aa 120 * pulses per revolution, and PPI is pulses per inch, or the equivalent for
aberk 0:5c2ad81551aa 121 * any other unit of displacement. PPI can be calculated by taking the
aberk 0:5c2ad81551aa 122 * circumference of the wheel or encoder disk and dividing it by the number
aberk 0:5c2ad81551aa 123 * of pulses per revolution.
aberk 0:5c2ad81551aa 124 */
aberk 0:5c2ad81551aa 125
shobonwarrior 1:8658787f9ec5 126
shobonwarrior 1:8658787f9ec5 127
aberk 0:5c2ad81551aa 128 #ifndef QEI_H
aberk 0:5c2ad81551aa 129 #define QEI_H
shobonwarrior 1:8658787f9ec5 130
shobonwarrior 1:8658787f9ec5 131
aberk 0:5c2ad81551aa 132 #include "mbed.h"
shobonwarrior 1:8658787f9ec5 133
shobonwarrior 1:8658787f9ec5 134
aberk 0:5c2ad81551aa 135 #define PREV_MASK 0x1 //Mask for the previous state in determining direction
aberk 0:5c2ad81551aa 136 //of rotation.
aberk 0:5c2ad81551aa 137 #define CURR_MASK 0x2 //Mask for the current state in determining direction
aberk 0:5c2ad81551aa 138 //of rotation.
aberk 0:5c2ad81551aa 139 #define INVALID 0x3 //XORing two states where both bits have changed.
shobonwarrior 1:8658787f9ec5 140
aberk 0:5c2ad81551aa 141 class QEI {
shobonwarrior 1:8658787f9ec5 142
aberk 0:5c2ad81551aa 143 public:
shobonwarrior 1:8658787f9ec5 144
aberk 0:5c2ad81551aa 145 typedef enum Encoding {
shobonwarrior 1:8658787f9ec5 146
aberk 0:5c2ad81551aa 147 X2_ENCODING,
aberk 0:5c2ad81551aa 148 X4_ENCODING
shobonwarrior 1:8658787f9ec5 149
aberk 0:5c2ad81551aa 150 } Encoding;
shobonwarrior 1:8658787f9ec5 151
shobonwarrior 1:8658787f9ec5 152
aberk 0:5c2ad81551aa 153 QEI(PinName channelA, PinName channelB, PinName index, int pulsesPerRev, Encoding encoding = X2_ENCODING);
shobonwarrior 1:8658787f9ec5 154
aberk 0:5c2ad81551aa 155 void reset(void);
shobonwarrior 1:8658787f9ec5 156
aberk 0:5c2ad81551aa 157 int getCurrentState(void);
shobonwarrior 1:8658787f9ec5 158
shobonwarrior 1:8658787f9ec5 159
shobonwarrior 1:8658787f9ec5 160 void set(int pul , int rev);
shobonwarrior 1:8658787f9ec5 161
aberk 0:5c2ad81551aa 162 int getPulses(void);
shobonwarrior 1:8658787f9ec5 163
aberk 0:5c2ad81551aa 164 int getRevolutions(void);
shobonwarrior 1:8658787f9ec5 165
shobonwarrior 1:8658787f9ec5 166 int getAng_rev();
shobonwarrior 1:8658787f9ec5 167
shobonwarrior 1:8658787f9ec5 168 double getAngle();
shobonwarrior 1:8658787f9ec5 169 double getSumangle();
shobonwarrior 1:8658787f9ec5 170 double getRPM();
shobonwarrior 1:8658787f9ec5 171 double getRPS();
shobonwarrior 1:8658787f9ec5 172 double getRPMS();
shobonwarrior 1:8658787f9ec5 173 double getRPUS();
shobonwarrior 1:8658787f9ec5 174 int pulsesPerRev_;
aberk 0:5c2ad81551aa 175 private:
shobonwarrior 1:8658787f9ec5 176 Timer Mper , Rper ,MSper ,USper;
shobonwarrior 1:8658787f9ec5 177 Ticker Tick;
shobonwarrior 1:8658787f9ec5 178 double RPM , RPS ,RPMS , RPUS;
shobonwarrior 1:8658787f9ec5 179
aberk 0:5c2ad81551aa 180 void encode(void);
shobonwarrior 1:8658787f9ec5 181
shobonwarrior 1:8658787f9ec5 182
aberk 0:5c2ad81551aa 183 void index(void);
shobonwarrior 1:8658787f9ec5 184
aberk 0:5c2ad81551aa 185 Encoding encoding_;
shobonwarrior 1:8658787f9ec5 186
aberk 0:5c2ad81551aa 187 InterruptIn channelA_;
aberk 0:5c2ad81551aa 188 InterruptIn channelB_;
aberk 0:5c2ad81551aa 189 InterruptIn index_;
shobonwarrior 1:8658787f9ec5 190 int round_rev;
shobonwarrior 1:8658787f9ec5 191
aberk 0:5c2ad81551aa 192 int prevState_;
aberk 0:5c2ad81551aa 193 int currState_;
shobonwarrior 1:8658787f9ec5 194 double angle_ , sumangle;
shobonwarrior 1:8658787f9ec5 195 int angle_pulses;
aberk 0:5c2ad81551aa 196 volatile int pulses_;
aberk 0:5c2ad81551aa 197 volatile int revolutions_;
shobonwarrior 1:8658787f9ec5 198
aberk 0:5c2ad81551aa 199 };
shobonwarrior 1:8658787f9ec5 200
shobonwarrior 1:8658787f9ec5 201 #endif
shobonwarrior 1:8658787f9ec5 202
shobonwarrior 1:8658787f9ec5 203 /*
shobonwarrior 1:8658787f9ec5 204 Repository toolbox
shobonwarrior 1:8658787f9ec5 205 Import into Compiler
shobonwarrior 1:8658787f9ec5 206 Export to desktop IDE
shobonwarrior 1:8658787f9ec5 207 Repository details
shobonwarrior 1:8658787f9ec5 208 Type: Library
shobonwarrior 1:8658787f9ec5 209 Created: 17 4月 2015
shobonwarrior 1:8658787f9ec5 210 Imports: 195
shobonwarrior 1:8658787f9ec5 211 Forks: 1
shobonwarrior 1:8658787f9ec5 212 Commits: 1
shobonwarrior 1:8658787f9ec5 213 Dependents: 0
shobonwarrior 1:8658787f9ec5 214 Dependencies: 0
shobonwarrior 1:8658787f9ec5 215 Followers: 5
shobonwarrior 1:8658787f9ec5 216 Software licencing information
aberk 0:5c2ad81551aa 217
shobonwarrior 1:8658787f9ec5 218
shobonwarrior 1:8658787f9ec5 219 The code in this repository is Apache licensed.
shobonwarrior 1:8658787f9ec5 220
shobonwarrior 1:8658787f9ec5 221 */