debounce_button.cpp

00001 #include "debounce_button.h"
00002 
00003 DigitalIn button(USER_BUTTON);
00004 DigitalOut led1(LED1);
00005 DigitalOut led2(LED2);
00006 volatile bool button1_enabled = true;
00007 volatile bool button1_buzy = false;
00008 Timeout someTimeout;
00009 Timeout timer;
00010 int counter = 0;
00011 /**
00012     Some tips and tricks:
00013     -   To use the built-in LED:
00014             DigitalOut led1(LED1);
00015             ...
00016             led1 = 1;
00017     -   To delay the call of a function:
00018             Timeout someTimeout;
00019             ...
00020             someTimeout.attach(callback(&someFunction), 0.5) with 0.5 as 500 milliseconds
00021     -   The variables that are used in interrupt callbacks have to be volatile, 
00022         because these variables can change at any time. Therefore, the compiler is not 
00023         going to make optimisations.
00024 */
00025 
00026 /**
00027     TODO
00028     ----
00029     This function:
00030         -   stores the amount of clicks in a variable which is read by the main loop.
00031         -   resets the click counter which is used inside this file.
00032         -   lowers a flag which tells the main loop that the user stopped pressing the button
00033             such that it can proceed its program.
00034         -   turns the built-in LED off. Therefore, the user gets informed that the program stopped counting the clicks.
00035 */
00036 
00037 void replay(){
00038     //replay the multiclick
00039     for(int i=0;i<counter;i++){
00040         led2 = 1;
00041         wait(0.2);
00042         led2 =0;
00043         wait(0.2);
00044     }
00045 }
00046 
00047 // This function enables the button again, such that unwanted clicks of the bouncing button get ignored.
00048 void button1_enabled_cb(void)
00049 {
00050     button1_enabled = true;
00051     led1 = 0;
00052     replay();
00053 }
00054 
00055 /**
00056     TODO
00057     ----
00058     This function:
00059         -   turns the built-in LED on, so the user gets informed that the program has started with counting clicks
00060         -   disables the button such that the debouncer is active
00061         -   enables the button again after a certain amount of time 
00062             (use interrupts with "button1_enabled_cb()" as callback.
00063         -   counts the amount of clicks within a period of 1 second
00064         -   informs the main loop that the button has been pressed
00065         -   informs the main loop that the user is clicking the button.
00066             Therefore, this main loop cannot continue its procedure until the clicks within 1 second have been counted.
00067 */
00068 
00069 void button1_busy_enable(){
00070     button1_buzy = false;    
00071 }
00072 void button1_onpressed_cb(void)
00073 {
00074     //button is pressed first time, turn led on
00075     if(button1_enabled){
00076         counter = 0;
00077         // turns the built-in LED on, so the user gets informed that the program has started with counting clicks
00078         led1 = 1;
00079         //disables the button such that the debouncer is active
00080         button1_enabled = false;
00081         button1_buzy = true;
00082         timer.attach(callback(&button1_busy_enable),0.1);
00083         // enables the button again after a certain amount of time (use interrupts with "button1_enabled_cb()" as callback.
00084         someTimeout.attach(callback(&button1_enabled_cb), 5);
00085     }else if(!button1_buzy){
00086         counter++;
00087         button1_buzy = true;
00088         timer.attach(callback(&button1_busy_enable),0.1);
00089     }
00090     
00091 }