main.cpp

00001 #include "mbed.h"
00002 
00003 //A slight improvement - however, the pressing of the switch still registers
00004 //spurious falling edges!
00005 
00006 void sw1TimeOutHandler();
00007 void sw1FallingEdge();
00008 
00009 
00010 #define EDGE_RISEN 1
00011 #define EDGE_FALLEN 0
00012 
00013 //Global Objects
00014 DigitalOut  red_led(D7);
00015 DigitalOut  green_led(D5);
00016 InterruptIn   sw1(D4);
00017 InterruptIn   sw2(D3);
00018 
00019 Timeout sw1TimeOut;             //Used to prevent switch bounce
00020 
00021 //Interrupt service routine for handling the timeout
00022 void sw1TimeOutHandler() {
00023     sw1TimeOut.detach();        //Stop the timeout counter firing
00024     sw1.fall(&sw1FallingEdge);  //Now wait for a falling edge
00025 }
00026 
00027 //Interrupt service routive for SW1 falling edge (release)
00028 void sw1FallingEdge() {
00029     sw1.fall(NULL);                             //Disable this interrupt
00030     red_led = !red_led;                         //Toggle LED    
00031     sw1TimeOut.attach(&sw1TimeOutHandler, 0.2); //Start timeout counter    
00032 }
00033 
00034 //Main - only has to initialise and sleep
00035 int main() {
00036     //Initial logging message
00037     puts("START");
00038     
00039     //Initial state
00040     red_led    = 0; //Set RED LED to OFF
00041     green_led  = 1;
00042     
00043     //Configure interrupts, wait for first rising edge
00044     sw1.fall(&sw1FallingEdge);
00045     
00046     //Main Polling Loop
00047     while (true) {
00048         
00049         //Put CPU back to sleep
00050         sleep();
00051         
00052         //You can ONLY reach this point if an ISR wakes the CPU
00053         puts("ISR just woke the MPU");
00054         
00055     } //end while
00056 
00057 }