Michael Ruck / Quadrature_Encoder_Switch

Quadrature Encoder Switch (Alps EC11)

EncoderSwitch.cpp@1:7d24b4076453, 2015-04-01 (annotated)

Committer:
michaelruck
Date:
Wed Apr 01 05:43:10 2015 +0000
Revision:
1:7d24b4076453
Parent:
0:1330a261101d 
Added Timeout to prevent isr chattering

Who changed what in which revision?

UserRevisionLine numberNew contents of line
michaelruck 0:1330a261101d 1 /* michael@ruck.com märz 2015 v0.1*/
michaelruck 0:1330a261101d 2 // Important! Two different EXTI Lines from 0 to 4!
michaelruck 0:1330a261101d 3 // Encoder Alps EC11
michaelruck 0:1330a261101d 4
michaelruck 0:1330a261101d 5 #include "mbed.h"
michaelruck 0:1330a261101d 6 #include "EncoderSwitch.h"
michaelruck 0:1330a261101d 7
michaelruck 0:1330a261101d 8 EncoderSwitch::EncoderSwitch(PinName pinA, PinName pinB, PinMode pull) : _pinA(pinA), _pinB(pinB)
michaelruck 0:1330a261101d 9 {
michaelruck 0:1330a261101d 10 _pinA.mode(pull);
michaelruck 0:1330a261101d 11 _pinB.mode(pull);
michaelruck 0:1330a261101d 12
michaelruck 0:1330a261101d 13 _pinA.fall(this, &EncoderSwitch::isra);
michaelruck 0:1330a261101d 14 _pinA.rise(this, &EncoderSwitch::isra);
michaelruck 0:1330a261101d 15
michaelruck 0:1330a261101d 16 _pinB.fall(this, &EncoderSwitch::isrb);
michaelruck 0:1330a261101d 17 _pinB.rise(this, &EncoderSwitch::isrb);
michaelruck 1:7d24b4076453 18
michaelruck 0:1330a261101d 19 _limit_down=0;
michaelruck 0:1330a261101d 20 _limit_up=9;
michaelruck 0:1330a261101d 21 _increment=0;
michaelruck 0:1330a261101d 22 }
michaelruck 0:1330a261101d 23
michaelruck 0:1330a261101d 24 EncoderSwitch::~EncoderSwitch() {/*none*/}
michaelruck 0:1330a261101d 25
michaelruck 1:7d24b4076453 26 void EncoderSwitch::_enable_isr()
michaelruck 1:7d24b4076453 27 {
michaelruck 1:7d24b4076453 28 _pinA.enable_irq();
michaelruck 1:7d24b4076453 29 _pinB.enable_irq();
michaelruck 1:7d24b4076453 30 }
michaelruck 1:7d24b4076453 31
michaelruck 0:1330a261101d 32 void EncoderSwitch::isra()
michaelruck 0:1330a261101d 33 {
michaelruck 1:7d24b4076453 34 _pinA.disable_irq();
michaelruck 1:7d24b4076453 35 _pinB.disable_irq();
michaelruck 1:7d24b4076453 36 _timeout.attach_us(this, &EncoderSwitch::_enable_isr, 500);
michaelruck 0:1330a261101d 37 int8_t state_a = _pinA.read();
michaelruck 0:1330a261101d 38 int8_t state_b = _pinB.read();
michaelruck 0:1330a261101d 39 if(state_a != state_b) _increment = 1;
michaelruck 0:1330a261101d 40 if((state_a == state_b) && (_increment == -1)) {
michaelruck 0:1330a261101d 41 counter(_increment);
michaelruck 0:1330a261101d 42 _increment = 0;
michaelruck 0:1330a261101d 43 }
michaelruck 0:1330a261101d 44 }
michaelruck 0:1330a261101d 45
michaelruck 0:1330a261101d 46 void EncoderSwitch::isrb()
michaelruck 0:1330a261101d 47 {
michaelruck 1:7d24b4076453 48 _pinA.disable_irq();
michaelruck 1:7d24b4076453 49 _pinB.disable_irq();
michaelruck 1:7d24b4076453 50 _timeout.attach_us(this, &EncoderSwitch::_enable_isr, 500);
michaelruck 0:1330a261101d 51 int8_t state_a = _pinA.read();
michaelruck 0:1330a261101d 52 int8_t state_b = _pinB.read();
michaelruck 0:1330a261101d 53 if(state_a != state_b) _increment = -1;
michaelruck 0:1330a261101d 54 if((state_a == state_b) && (_increment == 1)) {
michaelruck 0:1330a261101d 55 counter(_increment);
michaelruck 0:1330a261101d 56 _increment = 0;
michaelruck 0:1330a261101d 57 }
michaelruck 0:1330a261101d 58 }
michaelruck 0:1330a261101d 59
michaelruck 0:1330a261101d 60
michaelruck 0:1330a261101d 61
michaelruck 0:1330a261101d 62 void EncoderSwitch::setLimits(int16_t limit_down, int16_t limit_up)
michaelruck 0:1330a261101d 63 {
michaelruck 0:1330a261101d 64 _limit_down=limit_down;
michaelruck 0:1330a261101d 65 _limit_up=limit_up;
michaelruck 0:1330a261101d 66 }
michaelruck 0:1330a261101d 67
michaelruck 0:1330a261101d 68 void EncoderSwitch::counter(int16_t increment)
michaelruck 0:1330a261101d 69 {
michaelruck 0:1330a261101d 70 if(increment != 0) {
michaelruck 0:1330a261101d 71 if((count+increment <= _limit_up) & (count+increment >= _limit_down)) count = count+increment;
michaelruck 0:1330a261101d 72 else if(count+increment > _limit_up) count = _limit_down;
michaelruck 0:1330a261101d 73 else if(count+increment < _limit_down) count = _limit_up;
michaelruck 0:1330a261101d 74 }
michaelruck 0:1330a261101d 75 }