Debounce.cpp

00001 #include "mbed.h"
00002 
00003 Serial pc(USBTX, USBRX);
00004 DigitalIn btn(USER_BUTTON);
00005 DigitalOut led(LED1);
00006 Timer timer;
00007 Timer debounce;
00008 
00009 bool state = false;
00010 bool prevState = false;
00011 bool counting = false;
00012 
00013 int main() {
00014     while(true) {
00015         state = btn;
00016         if(state != prevState) {
00017             debounce.start();
00018         }
00019         if(debounce.read_ms() > 20) {
00020             debounce.stop();
00021             debounce.reset();
00022             if(!state) {
00023                 if(!counting) {
00024                     counting = true;
00025                     led = true;
00026                     timer.start();
00027                 } else {
00028                     counting = false;
00029                     led = false;
00030                     timer.stop();
00031                     pc.printf("%i ms\n", timer.read_ms());
00032                     timer.reset();
00033                 }
00034             }
00035         }
00036         prevState = state;
00037     }
00038 }