Ellie Griffiths / Mbed 2 deprecated TeabagControlDevice

An updated and more polished version of the earlier TeaBasic. This is now finished and works like a treat.

DebouncedIn.cpp@0:36264f703f1c, 2011-06-29 (annotated)

Committer:
Eggotape
Date:
Wed Jun 29 13:20:33 2011 +0000
Revision:
0:36264f703f1c
Haven\t tried it with water yet, so may want to consider slowing the Servo down to avoid splashing.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Eggotape 0:36264f703f1c 1 #include "DebouncedIn.h"
Eggotape 0:36264f703f1c 2 #include "mbed.h"
Eggotape 0:36264f703f1c 3
Eggotape 0:36264f703f1c 4 /*
Eggotape 0:36264f703f1c 5 * Constructor
Eggotape 0:36264f703f1c 6 */
Eggotape 0:36264f703f1c 7 DebouncedIn::DebouncedIn(PinName in)
Eggotape 0:36264f703f1c 8 : _in(in) {
Eggotape 0:36264f703f1c 9
Eggotape 0:36264f703f1c 10 // reset all the flags and counters
Eggotape 0:36264f703f1c 11 _samples = 0;
Eggotape 0:36264f703f1c 12 _output = 0;
Eggotape 0:36264f703f1c 13 _output_last = 0;
Eggotape 0:36264f703f1c 14 _rising_flag = 0;
Eggotape 0:36264f703f1c 15 _falling_flag = 0;
Eggotape 0:36264f703f1c 16 _state_counter = 0;
Eggotape 0:36264f703f1c 17
Eggotape 0:36264f703f1c 18 // Attach ticker
Eggotape 0:36264f703f1c 19 _ticker.attach(this, &DebouncedIn::_sample, 0.005);
Eggotape 0:36264f703f1c 20 }
Eggotape 0:36264f703f1c 21
Eggotape 0:36264f703f1c 22 void DebouncedIn::_sample() {
Eggotape 0:36264f703f1c 23
Eggotape 0:36264f703f1c 24 // take a sample
Eggotape 0:36264f703f1c 25 _samples = _samples >> 1; // shift left
Eggotape 0:36264f703f1c 26
Eggotape 0:36264f703f1c 27 if (_in) {
Eggotape 0:36264f703f1c 28 _samples |= 0x80;
Eggotape 0:36264f703f1c 29 }
Eggotape 0:36264f703f1c 30
Eggotape 0:36264f703f1c 31 // examine the sample window, look for steady state
Eggotape 0:36264f703f1c 32 if (_samples == 0x00) {
Eggotape 0:36264f703f1c 33 _output = 0;
Eggotape 0:36264f703f1c 34 }
Eggotape 0:36264f703f1c 35 else if (_samples == 0xFF) {
Eggotape 0:36264f703f1c 36 _output = 1;
Eggotape 0:36264f703f1c 37 }
Eggotape 0:36264f703f1c 38
Eggotape 0:36264f703f1c 39
Eggotape 0:36264f703f1c 40 // Rising edge detection
Eggotape 0:36264f703f1c 41 if ((_output == 1) && (_output_last == 0)) {
Eggotape 0:36264f703f1c 42 _rising_flag++;
Eggotape 0:36264f703f1c 43 _state_counter = 0;
Eggotape 0:36264f703f1c 44 }
Eggotape 0:36264f703f1c 45
Eggotape 0:36264f703f1c 46 // Falling edge detection
Eggotape 0:36264f703f1c 47 else if ((_output == 0) && (_output_last == 1)) {
Eggotape 0:36264f703f1c 48 _falling_flag++;
Eggotape 0:36264f703f1c 49 _state_counter = 0;
Eggotape 0:36264f703f1c 50 }
Eggotape 0:36264f703f1c 51
Eggotape 0:36264f703f1c 52 // steady state
Eggotape 0:36264f703f1c 53 else {
Eggotape 0:36264f703f1c 54 _state_counter++;
Eggotape 0:36264f703f1c 55 }
Eggotape 0:36264f703f1c 56
Eggotape 0:36264f703f1c 57 // update the output
Eggotape 0:36264f703f1c 58 _output_last = _output;
Eggotape 0:36264f703f1c 59
Eggotape 0:36264f703f1c 60 }
Eggotape 0:36264f703f1c 61
Eggotape 0:36264f703f1c 62
Eggotape 0:36264f703f1c 63
Eggotape 0:36264f703f1c 64 // return number of rising edges
Eggotape 0:36264f703f1c 65 int DebouncedIn::rising(void) {
Eggotape 0:36264f703f1c 66 int return_value = _rising_flag;
Eggotape 0:36264f703f1c 67 _rising_flag = 0;
Eggotape 0:36264f703f1c 68 return(return_value);
Eggotape 0:36264f703f1c 69 }
Eggotape 0:36264f703f1c 70
Eggotape 0:36264f703f1c 71 // return number of falling edges
Eggotape 0:36264f703f1c 72 int DebouncedIn::falling(void) {
Eggotape 0:36264f703f1c 73 int return_value = _falling_flag;
Eggotape 0:36264f703f1c 74 _falling_flag = 0;
Eggotape 0:36264f703f1c 75 return(return_value);
Eggotape 0:36264f703f1c 76 }
Eggotape 0:36264f703f1c 77
Eggotape 0:36264f703f1c 78 // return number of ticsk we've bene steady for
Eggotape 0:36264f703f1c 79 int DebouncedIn::steady(void) {
Eggotape 0:36264f703f1c 80 return(_state_counter);
Eggotape 0:36264f703f1c 81 }
Eggotape 0:36264f703f1c 82
Eggotape 0:36264f703f1c 83 // return the debounced status
Eggotape 0:36264f703f1c 84 int DebouncedIn::read(void) {
Eggotape 0:36264f703f1c 85 return(_output);
Eggotape 0:36264f703f1c 86 }
Eggotape 0:36264f703f1c 87
Eggotape 0:36264f703f1c 88 // shorthand for read()
Eggotape 0:36264f703f1c 89 DebouncedIn::operator int() {
Eggotape 0:36264f703f1c 90 return read();
Eggotape 0:36264f703f1c 91 }
Eggotape 0:36264f703f1c 92
Eggotape 0:36264f703f1c 93