Ian Aherne
driver for incremental encoder
decoder.cpp@4:9913990cfd78, 2019-03-12 (annotated)
- Committer:
- ianaherne
- Date:
- Tue Mar 12 18:12:04 2019 +0000
- Revision:
- 4:9913990cfd78
- Parent:
- 2:b82d31306c4b
- Child:
- 5:1a5772466668
streamlined encoder reading
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| ianaherne | 0:c3a05fe15b84 | 1 | #include "decoder.h" |
| ianaherne | 0:c3a05fe15b84 | 2 | |
| ianaherne | 0:c3a05fe15b84 | 3 | /** |
| ianaherne | 0:c3a05fe15b84 | 4 | * @brief constructor |
| ianaherne | 0:c3a05fe15b84 | 5 | * @details initializes interrupt on channel A, and initialises internal variables |
| ianaherne | 0:c3a05fe15b84 | 6 | * @param NA |
| ianaherne | 0:c3a05fe15b84 | 7 | * @return NA |
| ianaherne | 0:c3a05fe15b84 | 8 | * @warning interrupt functionallity on channel B is not used as it is not required. |
| ianaherne | 0:c3a05fe15b84 | 9 | * |
| ianaherne | 0:c3a05fe15b84 | 10 | */ |
| ianaherne | 0:c3a05fe15b84 | 11 | |
| ianaherne | 0:c3a05fe15b84 | 12 | decoder :: decoder(PinName channelA, PinName channelB):_channelA(channelA),_channelB(channelB) { |
| ianaherne | 0:c3a05fe15b84 | 13 | |
| ianaherne | 0:c3a05fe15b84 | 14 | _channelA.rise(this, &decoder::isr); |
| ianaherne | 4:9913990cfd78 | 15 | |
| ianaherne | 0:c3a05fe15b84 | 16 | _count = 0; |
| ianaherne | 0:c3a05fe15b84 | 17 | _direction = 0; |
| ianaherne | 0:c3a05fe15b84 | 18 | |
| ianaherne | 0:c3a05fe15b84 | 19 | } |
| ianaherne | 0:c3a05fe15b84 | 20 | |
| ianaherne | 0:c3a05fe15b84 | 21 | /** |
| ianaherne | 0:c3a05fe15b84 | 22 | * @brief isr |
| ianaherne | 0:c3a05fe15b84 | 23 | * @details interrupt servive routine to decode the encoder output |
| ianaherne | 0:c3a05fe15b84 | 24 | * @param NA |
| ianaherne | 0:c3a05fe15b84 | 25 | * @return NA |
| ianaherne | 0:c3a05fe15b84 | 26 | * @warning |
| ianaherne | 0:c3a05fe15b84 | 27 | * |
| ianaherne | 0:c3a05fe15b84 | 28 | */ |
| ianaherne | 0:c3a05fe15b84 | 29 | |
| ianaherne | 0:c3a05fe15b84 | 30 | |
| ianaherne | 0:c3a05fe15b84 | 31 | |
| ianaherne | 0:c3a05fe15b84 | 32 | void decoder :: isr(){ |
| ianaherne | 0:c3a05fe15b84 | 33 | |
| ianaherne | 4:9913990cfd78 | 34 | |
| ianaherne | 0:c3a05fe15b84 | 35 | uint8_t chA = _channelA.read(); |
| ianaherne | 4:9913990cfd78 | 36 | |
| ianaherne | 0:c3a05fe15b84 | 37 | uint8_t chB = _channelB.read(); |
| ianaherne | 0:c3a05fe15b84 | 38 | |
| ianaherne | 0:c3a05fe15b84 | 39 | if(chA == 1){ |
| ianaherne | 0:c3a05fe15b84 | 40 | |
| ianaherne | 4:9913990cfd78 | 41 | if(chB == 1){ |
| ianaherne | 4:9913990cfd78 | 42 | |
| ianaherne | 4:9913990cfd78 | 43 | if( _count != UPPER_LIMIT){ |
| ianaherne | 4:9913990cfd78 | 44 | _count++; |
| ianaherne | 4:9913990cfd78 | 45 | } |
| ianaherne | 4:9913990cfd78 | 46 | _direction = 1; |
| ianaherne | 4:9913990cfd78 | 47 | |
| ianaherne | 4:9913990cfd78 | 48 | } |
| ianaherne | 4:9913990cfd78 | 49 | |
| ianaherne | 4:9913990cfd78 | 50 | |
| ianaherne | 0:c3a05fe15b84 | 51 | |
| ianaherne | 4:9913990cfd78 | 52 | if(chB == 0){ |
| ianaherne | 4:9913990cfd78 | 53 | |
| ianaherne | 4:9913990cfd78 | 54 | if(_count != LOWER_LIMIT){ |
| ianaherne | 4:9913990cfd78 | 55 | _count--; |
| ianaherne | 4:9913990cfd78 | 56 | } |
| ianaherne | 4:9913990cfd78 | 57 | _direction = 0; |
| ianaherne | 4:9913990cfd78 | 58 | |
| ianaherne | 4:9913990cfd78 | 59 | } |
| ianaherne | 4:9913990cfd78 | 60 | |
| ianaherne | 4:9913990cfd78 | 61 | } |
| ianaherne | 0:c3a05fe15b84 | 62 | |
| ianaherne | 0:c3a05fe15b84 | 63 | } |
| ianaherne | 0:c3a05fe15b84 | 64 | |
| ianaherne | 0:c3a05fe15b84 | 65 | /** |
| ianaherne | 0:c3a05fe15b84 | 66 | * @brief getDirection() |
| ianaherne | 0:c3a05fe15b84 | 67 | * @details function to return the class private variable _direction |
| ianaherne | 0:c3a05fe15b84 | 68 | * @param NA |
| ianaherne | 0:c3a05fe15b84 | 69 | * @return the direction of encoder |
| ianaherne | 0:c3a05fe15b84 | 70 | * @warning |
| ianaherne | 0:c3a05fe15b84 | 71 | * |
| ianaherne | 0:c3a05fe15b84 | 72 | */ |
| ianaherne | 0:c3a05fe15b84 | 73 | |
| ianaherne | 0:c3a05fe15b84 | 74 | int8_t decoder :: getDirection(){ |
| ianaherne | 0:c3a05fe15b84 | 75 | |
| ianaherne | 0:c3a05fe15b84 | 76 | return _direction; |
| ianaherne | 0:c3a05fe15b84 | 77 | |
| ianaherne | 0:c3a05fe15b84 | 78 | |
| ianaherne | 0:c3a05fe15b84 | 79 | |
| ianaherne | 0:c3a05fe15b84 | 80 | } |
| ianaherne | 0:c3a05fe15b84 | 81 | |
| ianaherne | 0:c3a05fe15b84 | 82 | /** |
| ianaherne | 0:c3a05fe15b84 | 83 | * @brief getCount |
| ianaherne | 0:c3a05fe15b84 | 84 | * @details function to return the class private variable _count |
| ianaherne | 0:c3a05fe15b84 | 85 | * @param NA |
| ianaherne | 0:c3a05fe15b84 | 86 | * @return the number of turns of encoder +/- |
| ianaherne | 0:c3a05fe15b84 | 87 | * @warning |
| ianaherne | 0:c3a05fe15b84 | 88 | * |
| ianaherne | 0:c3a05fe15b84 | 89 | */ |
| ianaherne | 0:c3a05fe15b84 | 90 | |
| ianaherne | 0:c3a05fe15b84 | 91 | int16_t decoder :: getCount(){ |
| ianaherne | 0:c3a05fe15b84 | 92 | |
| ianaherne | 0:c3a05fe15b84 | 93 | |
| ianaherne | 0:c3a05fe15b84 | 94 | return _count; |
| ianaherne | 0:c3a05fe15b84 | 95 | |
| ianaherne | 0:c3a05fe15b84 | 96 | } |
| ianaherne | 0:c3a05fe15b84 | 97 | |
| ianaherne | 1:017efde7ab29 | 98 | /** |
| ianaherne | 1:017efde7ab29 | 99 | * @brief reset() |
| ianaherne | 1:017efde7ab29 | 100 | * @details function to reset all internal counting and directional variables |
| ianaherne | 1:017efde7ab29 | 101 | * @param NA |
| ianaherne | 1:017efde7ab29 | 102 | * @return |
| ianaherne | 1:017efde7ab29 | 103 | * @warning |
| ianaherne | 1:017efde7ab29 | 104 | * |
| ianaherne | 1:017efde7ab29 | 105 | */ |
| ianaherne | 1:017efde7ab29 | 106 | |
| ianaherne | 1:017efde7ab29 | 107 | void decoder :: reset(){ |
| ianaherne | 1:017efde7ab29 | 108 | |
| ianaherne | 4:9913990cfd78 | 109 | |
| ianaherne | 1:017efde7ab29 | 110 | _count = 0; |
| ianaherne | 1:017efde7ab29 | 111 | _direction = 0; |
| ianaherne | 1:017efde7ab29 | 112 | |
| ianaherne | 1:017efde7ab29 | 113 | } |
| ianaherne | 1:017efde7ab29 | 114 |