Krishna Kaushal Panduru
/
QuadratureEncoder
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quadratureEncoder.cpp@1:52fba054be6c, 2011-07-22 (annotated)
- Committer:
- kaushalpkk
- Date:
- Fri Jul 22 15:11:28 2011 +0000
- Revision:
- 1:52fba054be6c
- Parent:
- 0:6b30097d9a45
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| kaushalpkk | 0:6b30097d9a45 | 1 | /* |
| kaushalpkk | 0:6b30097d9a45 | 2 | name: encoder.h |
| kaushalpkk | 0:6b30097d9a45 | 3 | date: 04-june-2011 |
| kaushalpkk | 0:6b30097d9a45 | 4 | header description: contains functions and external variables to interface quadrature encoder |
| kaushalpkk | 0:6b30097d9a45 | 5 | compiler-library: the mbed library interface is used on the whole.. |
| kaushalpkk | 0:6b30097d9a45 | 6 | compatability: can also be compatable with generalised code with diffrerent hardware and software |
| kaushalpkk | 0:6b30097d9a45 | 7 | hardware dependency: works on rover 5 model platform interfaced with mbed controller |
| kaushalpkk | 0:6b30097d9a45 | 8 | |
| kaushalpkk | 0:6b30097d9a45 | 9 | indentation: <mbed default intendation - 4 spaces> |
| kaushalpkk | 0:6b30097d9a45 | 10 | resources: http://www.sparkfun.com/products/10336 |
| kaushalpkk | 0:6b30097d9a45 | 11 | http://letsmakerobots.com/node/24031 |
| kaushalpkk | 0:6b30097d9a45 | 12 | http://www.sparkfun.com/datasheets/Robotics/Rover%205%20Introduction.pdf |
| kaushalpkk | 0:6b30097d9a45 | 13 | */ |
| kaushalpkk | 0:6b30097d9a45 | 14 | #include "mbed.h" |
| kaushalpkk | 0:6b30097d9a45 | 15 | #include "quadratureEncoder.h" |
| kaushalpkk | 0:6b30097d9a45 | 16 | //gets a bit position by shifting 1 |
| kaushalpkk | 0:6b30097d9a45 | 17 | #define Abit 0 |
| kaushalpkk | 0:6b30097d9a45 | 18 | #define Bbit 1 |
| kaushalpkk | 0:6b30097d9a45 | 19 | |
| kaushalpkk | 0:6b30097d9a45 | 20 | #define _BV(x) (1 << x) |
| kaushalpkk | 0:6b30097d9a45 | 21 | |
| kaushalpkk | 0:6b30097d9a45 | 22 | // sbi sets a particular bit and cbi clears the bit (target byte-word, bit position) |
| kaushalpkk | 0:6b30097d9a45 | 23 | #define sbi(y,x) y|=_BV(x) |
| kaushalpkk | 0:6b30097d9a45 | 24 | #define cbi(y,x) y&=~_BV(x) |
| kaushalpkk | 0:6b30097d9a45 | 25 | |
| kaushalpkk | 0:6b30097d9a45 | 26 | quadratureEncoder::quadratureEncoder(PinName pinA, PinName pinB): |
| kaushalpkk | 0:6b30097d9a45 | 27 | _pinA(pinA), _pinB(pinB){ |
| kaushalpkk | 0:6b30097d9a45 | 28 | _pinA.rise(this, &quadratureEncoder::ARise); |
| kaushalpkk | 0:6b30097d9a45 | 29 | _pinA.fall(this, &quadratureEncoder::AFall); |
| kaushalpkk | 0:6b30097d9a45 | 30 | _pinB.rise(this, &quadratureEncoder::BRise); |
| kaushalpkk | 0:6b30097d9a45 | 31 | _pinB.fall(this, &quadratureEncoder::BFall); |
| kaushalpkk | 0:6b30097d9a45 | 32 | |
| kaushalpkk | 0:6b30097d9a45 | 33 | _oldState = 0x00; |
| kaushalpkk | 0:6b30097d9a45 | 34 | _nowState = 0x00; |
| kaushalpkk | 0:6b30097d9a45 | 35 | _moved = 0; |
| kaushalpkk | 0:6b30097d9a45 | 36 | _count = 0; |
| kaushalpkk | 0:6b30097d9a45 | 37 | } |
| kaushalpkk | 0:6b30097d9a45 | 38 | |
| kaushalpkk | 0:6b30097d9a45 | 39 | //////////////////////////////////////////////////////////////////////////////////////// |
| kaushalpkk | 0:6b30097d9a45 | 40 | int quadratureEncoder::getCount() { |
| kaushalpkk | 1:52fba054be6c | 41 | return _count; |
| kaushalpkk | 0:6b30097d9a45 | 42 | } |
| kaushalpkk | 0:6b30097d9a45 | 43 | |
| kaushalpkk | 0:6b30097d9a45 | 44 | void quadratureEncoder::resetCount() { |
| kaushalpkk | 0:6b30097d9a45 | 45 | _count = 0; |
| kaushalpkk | 0:6b30097d9a45 | 46 | } |
| kaushalpkk | 0:6b30097d9a45 | 47 | |
| kaushalpkk | 0:6b30097d9a45 | 48 | void quadratureEncoder::setCount(int setCounter) { |
| kaushalpkk | 0:6b30097d9a45 | 49 | _count = setCounter; |
| kaushalpkk | 0:6b30097d9a45 | 50 | } |
| kaushalpkk | 0:6b30097d9a45 | 51 | |
| kaushalpkk | 0:6b30097d9a45 | 52 | |
| kaushalpkk | 0:6b30097d9a45 | 53 | |
| kaushalpkk | 0:6b30097d9a45 | 54 | //////////////////////////////////////////////////////////////////////////////////////// |
| kaushalpkk | 0:6b30097d9a45 | 55 | void quadratureEncoder::resetMoved() { |
| kaushalpkk | 0:6b30097d9a45 | 56 | _moved = 0; |
| kaushalpkk | 0:6b30097d9a45 | 57 | } |
| kaushalpkk | 0:6b30097d9a45 | 58 | |
| kaushalpkk | 0:6b30097d9a45 | 59 | void quadratureEncoder::setMoved(int setMover) { |
| kaushalpkk | 0:6b30097d9a45 | 60 | _moved = setMover; |
| kaushalpkk | 0:6b30097d9a45 | 61 | } |
| kaushalpkk | 0:6b30097d9a45 | 62 | |
| kaushalpkk | 0:6b30097d9a45 | 63 | int quadratureEncoder::getMoved() { |
| kaushalpkk | 0:6b30097d9a45 | 64 | return _moved; |
| kaushalpkk | 0:6b30097d9a45 | 65 | } |
| kaushalpkk | 0:6b30097d9a45 | 66 | |
| kaushalpkk | 0:6b30097d9a45 | 67 | //////////////////////////////////////////////////////////////////////////////////////// |
| kaushalpkk | 0:6b30097d9a45 | 68 | char quadratureEncoder::saveState(char nowS) { |
| kaushalpkk | 0:6b30097d9a45 | 69 | return nowS; |
| kaushalpkk | 0:6b30097d9a45 | 70 | } |
| kaushalpkk | 0:6b30097d9a45 | 71 | |
| kaushalpkk | 0:6b30097d9a45 | 72 | char quadratureEncoder::getBit(char bitP, char targB) { |
| kaushalpkk | 0:6b30097d9a45 | 73 | targB = targB & _BV(bitP); |
| kaushalpkk | 0:6b30097d9a45 | 74 | if (targB == 0) |
| kaushalpkk | 0:6b30097d9a45 | 75 | return 0; |
| kaushalpkk | 0:6b30097d9a45 | 76 | else |
| kaushalpkk | 0:6b30097d9a45 | 77 | return 1; |
| kaushalpkk | 0:6b30097d9a45 | 78 | } |
| kaushalpkk | 0:6b30097d9a45 | 79 | |
| kaushalpkk | 0:6b30097d9a45 | 80 | |
| kaushalpkk | 0:6b30097d9a45 | 81 | /* |
| kaushalpkk | 0:6b30097d9a45 | 82 | function: the following 8 functions are ISR called by rise and fall of 4 pins |
| kaushalpkk | 0:6b30097d9a45 | 83 | input: none (interupt called) |
| kaushalpkk | 0:6b30097d9a45 | 84 | output: none |
| kaushalpkk | 0:6b30097d9a45 | 85 | functioning:interrupts are called when the pin change occours |
| kaushalpkk | 0:6b30097d9a45 | 86 | sets or clears the respective bit |
| kaushalpkk | 0:6b30097d9a45 | 87 | checks the previous state and increments respective direction |
| kaushalpkk | 0:6b30097d9a45 | 88 | restores new state value into old state |
| kaushalpkk | 0:6b30097d9a45 | 89 | increments a count value for processing */ |
| kaushalpkk | 0:6b30097d9a45 | 90 | void quadratureEncoder::ARise() { |
| kaushalpkk | 0:6b30097d9a45 | 91 | sbi(_nowState,Abit); |
| kaushalpkk | 0:6b30097d9a45 | 92 | if (getBit(Bbit,_oldState)==0 && getBit(Abit,_oldState)==0) |
| kaushalpkk | 0:6b30097d9a45 | 93 | _moved++; |
| kaushalpkk | 0:6b30097d9a45 | 94 | else if (getBit(Bbit,_oldState)==0 && getBit(Abit,_oldState)==1) |
| kaushalpkk | 0:6b30097d9a45 | 95 | _moved--; |
| kaushalpkk | 0:6b30097d9a45 | 96 | _oldState = saveState(_nowState); |
| kaushalpkk | 0:6b30097d9a45 | 97 | _count++; |
| kaushalpkk | 0:6b30097d9a45 | 98 | } |
| kaushalpkk | 0:6b30097d9a45 | 99 | |
| kaushalpkk | 0:6b30097d9a45 | 100 | void quadratureEncoder::AFall() { |
| kaushalpkk | 0:6b30097d9a45 | 101 | cbi(_nowState, Abit); |
| kaushalpkk | 0:6b30097d9a45 | 102 | if (getBit(Bbit,_oldState)==1 && getBit(Abit,_oldState)==1) |
| kaushalpkk | 0:6b30097d9a45 | 103 | _moved++; |
| kaushalpkk | 0:6b30097d9a45 | 104 | else if (getBit(Bbit,_oldState)==1 && getBit(Abit,_oldState)==0) |
| kaushalpkk | 0:6b30097d9a45 | 105 | _moved--; |
| kaushalpkk | 0:6b30097d9a45 | 106 | _oldState = saveState(_nowState); |
| kaushalpkk | 0:6b30097d9a45 | 107 | _count++; |
| kaushalpkk | 0:6b30097d9a45 | 108 | } |
| kaushalpkk | 0:6b30097d9a45 | 109 | |
| kaushalpkk | 0:6b30097d9a45 | 110 | void quadratureEncoder::BRise() { |
| kaushalpkk | 0:6b30097d9a45 | 111 | sbi(_nowState,Bbit); |
| kaushalpkk | 0:6b30097d9a45 | 112 | if (getBit(Bbit,_oldState)==1 && getBit(Abit,_oldState)==0) |
| kaushalpkk | 0:6b30097d9a45 | 113 | _moved++; |
| kaushalpkk | 0:6b30097d9a45 | 114 | else if (getBit(Bbit,_oldState)==0 && getBit(Abit,_oldState)==0) |
| kaushalpkk | 0:6b30097d9a45 | 115 | _moved--; |
| kaushalpkk | 0:6b30097d9a45 | 116 | _oldState = saveState(_nowState); |
| kaushalpkk | 0:6b30097d9a45 | 117 | _count++; |
| kaushalpkk | 0:6b30097d9a45 | 118 | } |
| kaushalpkk | 0:6b30097d9a45 | 119 | |
| kaushalpkk | 0:6b30097d9a45 | 120 | void quadratureEncoder::BFall() { |
| kaushalpkk | 0:6b30097d9a45 | 121 | cbi(_nowState, Bbit); |
| kaushalpkk | 0:6b30097d9a45 | 122 | if (getBit(Bbit,_oldState)==0 && getBit(Abit,_oldState)==1) |
| kaushalpkk | 0:6b30097d9a45 | 123 | _moved++; |
| kaushalpkk | 0:6b30097d9a45 | 124 | else if (getBit(Bbit,_oldState)==1 && getBit(Abit,_oldState)==1) |
| kaushalpkk | 0:6b30097d9a45 | 125 | _moved--; |
| kaushalpkk | 0:6b30097d9a45 | 126 | _oldState = saveState(_nowState); |
| kaushalpkk | 0:6b30097d9a45 | 127 | _count++; |
| kaushalpkk | 0:6b30097d9a45 | 128 | } |
| kaushalpkk | 0:6b30097d9a45 | 129 |