Michael Shimniok / Mbed 2 deprecated DataBus

Code for autonomous rover for Sparkfun AVC. DataBus won 3rd in 2012 and the same code was used on Troubled Child, a 1986 Jeep Grand Wagoneer to win 1st in 2014.

Dependencies:   mbed Watchdog SDFileSystem DigoleSerialDisp

Sensors/IncrementalEncoder/IncrementalEncoder.cpp@25:bb5356402687, 2018-11-30 (annotated)

Committer:
shimniok
Date:
Fri Nov 30 16:11:53 2018 +0000
Revision:
25:bb5356402687
Parent:
23:a34af501ea89 
Initial publish of revised version.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
shimniok 0:a6a169de725f 1 #include "IncrementalEncoder.h"
shimniok 0:a6a169de725f 2
shimniok 0:a6a169de725f 3 IncrementalEncoder::IncrementalEncoder(PinName pin): _lastTicks(0), _ticks(0), _new(false), _interrupt(pin) {
shimniok 0:a6a169de725f 4 _interrupt.mode(PullNone); // default is pulldown but my encoder board uses a pull-up and that just don't work
shimniok 23:a34af501ea89 5 _interrupt.rise(callback(this, &IncrementalEncoder::_incRise));
shimniok 23:a34af501ea89 6 _interrupt.fall(callback(this, &IncrementalEncoder::_incFall));
shimniok 0:a6a169de725f 7 _t.start();
shimniok 0:a6a169de725f 8 _t.reset();
shimniok 0:a6a169de725f 9 _lastTime = _t.read_us();
shimniok 0:a6a169de725f 10 }
shimniok 0:a6a169de725f 11
shimniok 0:a6a169de725f 12 unsigned int IncrementalEncoder::read() {
shimniok 0:a6a169de725f 13 // disable interrupts?
shimniok 0:a6a169de725f 14 unsigned int ticks = _ticks - _lastTicks;
shimniok 0:a6a169de725f 15 _lastTicks = _ticks;
shimniok 0:a6a169de725f 16 _new=false;
shimniok 0:a6a169de725f 17 return ticks;
shimniok 0:a6a169de725f 18 }
shimniok 0:a6a169de725f 19
shimniok 0:a6a169de725f 20 unsigned int IncrementalEncoder::readTotal() {
shimniok 0:a6a169de725f 21 _new=false;
shimniok 0:a6a169de725f 22 return _ticks;
shimniok 0:a6a169de725f 23 }
shimniok 0:a6a169de725f 24
shimniok 0:a6a169de725f 25 unsigned int IncrementalEncoder::readRise() {
shimniok 0:a6a169de725f 26 _new=false;
shimniok 0:a6a169de725f 27 return _rise;
shimniok 0:a6a169de725f 28 }
shimniok 0:a6a169de725f 29
shimniok 0:a6a169de725f 30 unsigned int IncrementalEncoder::readFall() {
shimniok 0:a6a169de725f 31 _new=false;
shimniok 0:a6a169de725f 32 return _fall;
shimniok 0:a6a169de725f 33 }
shimniok 0:a6a169de725f 34
shimniok 0:a6a169de725f 35 unsigned int IncrementalEncoder::readTime() {
shimniok 0:a6a169de725f 36 return _time;
shimniok 0:a6a169de725f 37 }
shimniok 0:a6a169de725f 38
shimniok 0:a6a169de725f 39 void IncrementalEncoder::reset() {
shimniok 0:a6a169de725f 40 _ticks = _lastTicks = 0;
shimniok 0:a6a169de725f 41 }
shimniok 0:a6a169de725f 42
shimniok 0:a6a169de725f 43 void IncrementalEncoder::_increment() {
shimniok 0:a6a169de725f 44 _ticks++;
shimniok 0:a6a169de725f 45 }
shimniok 0:a6a169de725f 46
shimniok 0:a6a169de725f 47 #define A 0.3 // mix in how much from previous readings?
shimniok 0:a6a169de725f 48 void IncrementalEncoder::_incRise() {
shimniok 0:a6a169de725f 49 _rise++;
shimniok 0:a6a169de725f 50 _ticks++;
shimniok 0:a6a169de725f 51 _new=true;
shimniok 0:a6a169de725f 52 // compute time between ticks; only do this for rise
shimniok 0:a6a169de725f 53 // to eliminate jitter
shimniok 0:a6a169de725f 54 int now = _t.read_us();
shimniok 0:a6a169de725f 55 _time = A*_time + (1-A)*(now - _lastTime);
shimniok 0:a6a169de725f 56 // Dead band: if _time > xxxx then turn off and wait until next tick
shimniok 0:a6a169de725f 57 // to start up again
shimniok 0:a6a169de725f 58 _lastTime = now;
shimniok 0:a6a169de725f 59 }
shimniok 0:a6a169de725f 60
shimniok 0:a6a169de725f 61 void IncrementalEncoder::_incFall() {
shimniok 0:a6a169de725f 62 _fall++;
shimniok 0:a6a169de725f 63 _ticks++;
shimniok 0:a6a169de725f 64 _new=true;
shimniok 0:a6a169de725f 65 }