Sergio Londono / Mbed 2 deprecated Tarea3

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Dependencies:   TextLCD-modificad mbed

DebouncedIn.cpp@0:9d62b34e332d, 2013-11-15 (annotated)

Committer:
salondonog
Date:
Fri Nov 15 17:43:51 2013 +0000
Revision:
0:9d62b34e332d
Pid

Who changed what in which revision?

UserRevisionLine numberNew contents of line
salondonog 0:9d62b34e332d 1 #include "DebouncedIn.h"
salondonog 0:9d62b34e332d 2 #include "mbed.h"
salondonog 0:9d62b34e332d 3
salondonog 0:9d62b34e332d 4 /*
salondonog 0:9d62b34e332d 5 * Constructor
salondonog 0:9d62b34e332d 6 */
salondonog 0:9d62b34e332d 7 DebouncedIn::DebouncedIn(PinName in)
salondonog 0:9d62b34e332d 8 : _in(in) {
salondonog 0:9d62b34e332d 9
salondonog 0:9d62b34e332d 10 // reset all the flags and counters
salondonog 0:9d62b34e332d 11 _samples = 0;
salondonog 0:9d62b34e332d 12 _output = 0;
salondonog 0:9d62b34e332d 13 _output_last = 0;
salondonog 0:9d62b34e332d 14 _rising_flag = 0;
salondonog 0:9d62b34e332d 15 _falling_flag = 0;
salondonog 0:9d62b34e332d 16 _state_counter = 0;
salondonog 0:9d62b34e332d 17
salondonog 0:9d62b34e332d 18 // Attach ticker
salondonog 0:9d62b34e332d 19 _ticker.attach(this, &DebouncedIn::_sample, 0.005);
salondonog 0:9d62b34e332d 20 }
salondonog 0:9d62b34e332d 21
salondonog 0:9d62b34e332d 22 void DebouncedIn::_sample() {
salondonog 0:9d62b34e332d 23
salondonog 0:9d62b34e332d 24 // take a sample
salondonog 0:9d62b34e332d 25 _samples = _samples >> 1; // shift left
salondonog 0:9d62b34e332d 26
salondonog 0:9d62b34e332d 27 if (_in) {
salondonog 0:9d62b34e332d 28 _samples |= 0x80;
salondonog 0:9d62b34e332d 29 }
salondonog 0:9d62b34e332d 30
salondonog 0:9d62b34e332d 31 // examine the sample window, look for steady state
salondonog 0:9d62b34e332d 32 if (_samples == 0x00) {
salondonog 0:9d62b34e332d 33 _output = 0;
salondonog 0:9d62b34e332d 34 }
salondonog 0:9d62b34e332d 35 else if (_samples == 0xFF) {
salondonog 0:9d62b34e332d 36 _output = 1;
salondonog 0:9d62b34e332d 37 }
salondonog 0:9d62b34e332d 38
salondonog 0:9d62b34e332d 39
salondonog 0:9d62b34e332d 40 // Rising edge detection
salondonog 0:9d62b34e332d 41 if ((_output == 1) && (_output_last == 0)) {
salondonog 0:9d62b34e332d 42 _rising_flag++;
salondonog 0:9d62b34e332d 43 _state_counter = 0;
salondonog 0:9d62b34e332d 44 }
salondonog 0:9d62b34e332d 45
salondonog 0:9d62b34e332d 46 // Falling edge detection
salondonog 0:9d62b34e332d 47 else if ((_output == 0) && (_output_last == 1)) {
salondonog 0:9d62b34e332d 48 _falling_flag++;
salondonog 0:9d62b34e332d 49 _state_counter = 0;
salondonog 0:9d62b34e332d 50 }
salondonog 0:9d62b34e332d 51
salondonog 0:9d62b34e332d 52 // steady state
salondonog 0:9d62b34e332d 53 else {
salondonog 0:9d62b34e332d 54 _state_counter++;
salondonog 0:9d62b34e332d 55 }
salondonog 0:9d62b34e332d 56
salondonog 0:9d62b34e332d 57 // update the output
salondonog 0:9d62b34e332d 58 _output_last = _output;
salondonog 0:9d62b34e332d 59
salondonog 0:9d62b34e332d 60 }
salondonog 0:9d62b34e332d 61
salondonog 0:9d62b34e332d 62
salondonog 0:9d62b34e332d 63
salondonog 0:9d62b34e332d 64 // return number of rising edges
salondonog 0:9d62b34e332d 65 int DebouncedIn::rising(void) {
salondonog 0:9d62b34e332d 66 int return_value = _rising_flag;
salondonog 0:9d62b34e332d 67 _rising_flag = 0;
salondonog 0:9d62b34e332d 68 return(return_value);
salondonog 0:9d62b34e332d 69 }
salondonog 0:9d62b34e332d 70
salondonog 0:9d62b34e332d 71 // return number of falling edges
salondonog 0:9d62b34e332d 72 int DebouncedIn::falling(void) {
salondonog 0:9d62b34e332d 73 int return_value = _falling_flag;
salondonog 0:9d62b34e332d 74 _falling_flag = 0;
salondonog 0:9d62b34e332d 75 return(return_value);
salondonog 0:9d62b34e332d 76 }
salondonog 0:9d62b34e332d 77
salondonog 0:9d62b34e332d 78 // return number of ticsk we've bene steady for
salondonog 0:9d62b34e332d 79 int DebouncedIn::steady(void) {
salondonog 0:9d62b34e332d 80 return(_state_counter);
salondonog 0:9d62b34e332d 81 }
salondonog 0:9d62b34e332d 82
salondonog 0:9d62b34e332d 83 // return the debounced status
salondonog 0:9d62b34e332d 84 int DebouncedIn::read(void) {
salondonog 0:9d62b34e332d 85 return(_output);
salondonog 0:9d62b34e332d 86 }
salondonog 0:9d62b34e332d 87
salondonog 0:9d62b34e332d 88 // shorthand for read()
salondonog 0:9d62b34e332d 89 DebouncedIn::operator int() {
salondonog 0:9d62b34e332d 90 return read();
salondonog 0:9d62b34e332d 91 }
salondonog 0:9d62b34e332d 92
salondonog 0:9d62b34e332d 93