Bhakti Kulkarni / IOT_HW_5_websockets

Homework_5_IOT

Dependencies:   C12832_lcd EthernetInterface LCD_fonts LM75B MMA7660 NTPClient SimpleSMTPClient WebSocketClient mbed-rtos mbed

DebouncedIn.cpp@0:40afd0d80b51, 2014-05-20 (annotated)

Committer:
bhakti08
Date:
Tue May 20 06:18:16 2014 +0000
Revision:
0:40afd0d80b51
Websockets

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bhakti08 0:40afd0d80b51 1 #include "DebouncedIn.h"
bhakti08 0:40afd0d80b51 2 #include "mbed.h"
bhakti08 0:40afd0d80b51 3
bhakti08 0:40afd0d80b51 4 /*
bhakti08 0:40afd0d80b51 5 * Constructor
bhakti08 0:40afd0d80b51 6 */
bhakti08 0:40afd0d80b51 7 DebouncedIn::DebouncedIn(PinName in)
bhakti08 0:40afd0d80b51 8 : _in(in) {
bhakti08 0:40afd0d80b51 9
bhakti08 0:40afd0d80b51 10 // reset all the flags and counters
bhakti08 0:40afd0d80b51 11 _samples = 0;
bhakti08 0:40afd0d80b51 12 _output = 0;
bhakti08 0:40afd0d80b51 13 _output_last = 0;
bhakti08 0:40afd0d80b51 14 _rising_flag = 0;
bhakti08 0:40afd0d80b51 15 _falling_flag = 0;
bhakti08 0:40afd0d80b51 16 _state_counter = 0;
bhakti08 0:40afd0d80b51 17
bhakti08 0:40afd0d80b51 18 // Attach ticker
bhakti08 0:40afd0d80b51 19 _ticker.attach(this, &DebouncedIn::_sample, 0.005);
bhakti08 0:40afd0d80b51 20 }
bhakti08 0:40afd0d80b51 21
bhakti08 0:40afd0d80b51 22 void DebouncedIn::_sample() {
bhakti08 0:40afd0d80b51 23
bhakti08 0:40afd0d80b51 24 // take a sample
bhakti08 0:40afd0d80b51 25 _samples = _samples >> 1; // shift left
bhakti08 0:40afd0d80b51 26
bhakti08 0:40afd0d80b51 27 if (_in) {
bhakti08 0:40afd0d80b51 28 _samples |= 0x80;
bhakti08 0:40afd0d80b51 29 }
bhakti08 0:40afd0d80b51 30
bhakti08 0:40afd0d80b51 31 // examine the sample window, look for steady state
bhakti08 0:40afd0d80b51 32 if (_samples == 0x00) {
bhakti08 0:40afd0d80b51 33 _output = 0;
bhakti08 0:40afd0d80b51 34 }
bhakti08 0:40afd0d80b51 35 else if (_samples == 0xFF) {
bhakti08 0:40afd0d80b51 36 _output = 1;
bhakti08 0:40afd0d80b51 37 }
bhakti08 0:40afd0d80b51 38
bhakti08 0:40afd0d80b51 39
bhakti08 0:40afd0d80b51 40 // Rising edge detection
bhakti08 0:40afd0d80b51 41 if ((_output == 1) && (_output_last == 0)) {
bhakti08 0:40afd0d80b51 42 _rising_flag++;
bhakti08 0:40afd0d80b51 43 _state_counter = 0;
bhakti08 0:40afd0d80b51 44 }
bhakti08 0:40afd0d80b51 45
bhakti08 0:40afd0d80b51 46 // Falling edge detection
bhakti08 0:40afd0d80b51 47 else if ((_output == 0) && (_output_last == 1)) {
bhakti08 0:40afd0d80b51 48 _falling_flag++;
bhakti08 0:40afd0d80b51 49 _state_counter = 0;
bhakti08 0:40afd0d80b51 50 }
bhakti08 0:40afd0d80b51 51
bhakti08 0:40afd0d80b51 52 // steady state
bhakti08 0:40afd0d80b51 53 else {
bhakti08 0:40afd0d80b51 54 _state_counter++;
bhakti08 0:40afd0d80b51 55 }
bhakti08 0:40afd0d80b51 56
bhakti08 0:40afd0d80b51 57 // update the output
bhakti08 0:40afd0d80b51 58 _output_last = _output;
bhakti08 0:40afd0d80b51 59
bhakti08 0:40afd0d80b51 60 }
bhakti08 0:40afd0d80b51 61
bhakti08 0:40afd0d80b51 62
bhakti08 0:40afd0d80b51 63
bhakti08 0:40afd0d80b51 64 // return number of rising edges
bhakti08 0:40afd0d80b51 65 int DebouncedIn::rising(void) {
bhakti08 0:40afd0d80b51 66 int return_value = _rising_flag;
bhakti08 0:40afd0d80b51 67 _rising_flag = 0;
bhakti08 0:40afd0d80b51 68 return(return_value);
bhakti08 0:40afd0d80b51 69 }
bhakti08 0:40afd0d80b51 70
bhakti08 0:40afd0d80b51 71 // return number of falling edges
bhakti08 0:40afd0d80b51 72 int DebouncedIn::falling(void) {
bhakti08 0:40afd0d80b51 73 int return_value = _falling_flag;
bhakti08 0:40afd0d80b51 74 _falling_flag = 0;
bhakti08 0:40afd0d80b51 75 return(return_value);
bhakti08 0:40afd0d80b51 76 }
bhakti08 0:40afd0d80b51 77
bhakti08 0:40afd0d80b51 78 // return number of ticsk we've bene steady for
bhakti08 0:40afd0d80b51 79 int DebouncedIn::steady(void) {
bhakti08 0:40afd0d80b51 80 return(_state_counter);
bhakti08 0:40afd0d80b51 81 }
bhakti08 0:40afd0d80b51 82
bhakti08 0:40afd0d80b51 83 // return the debounced status
bhakti08 0:40afd0d80b51 84 int DebouncedIn::read(void) {
bhakti08 0:40afd0d80b51 85 return(_output);
bhakti08 0:40afd0d80b51 86 }
bhakti08 0:40afd0d80b51 87
bhakti08 0:40afd0d80b51 88 // shorthand for read()
bhakti08 0:40afd0d80b51 89 DebouncedIn::operator int() {
bhakti08 0:40afd0d80b51 90 return read();
bhakti08 0:40afd0d80b51 91 }
bhakti08 0:40afd0d80b51 92
bhakti08 0:40afd0d80b51 93