debounce_button.cpp

00001 #include "debounce_button.h"
00002 
00003 DigitalOut led1(LED1);
00004 volatile int click_counter = 0;
00005 Timeout multiclick;
00006 Timeout debounce;
00007 
00008 /**
00009     Some tips and tricks:
00010     -   To use the built-in LED:
00011             DigitalOut led1(LED1);
00012             ...
00013             led1 = 1;
00014     -   To delay the call of a function:
00015             Timeout someTimeout;
00016             ...
00017             someTimeout.attach(callback(&someFunction), 0.5) with 0.5 as 500 milliseconds
00018     -   The variables that are used in interrupt callbacks have to be volatile, 
00019         because these variables can change at any time. Therefore, the compiler is not 
00020         going to make optimisations.
00021 */
00022 
00023 /**
00024     TODO
00025     ----
00026     This function:
00027         -   stores the amount of clicks in a variable which is read by the main loop.
00028         -   resets the click counter which is used inside this file.
00029         -   lowers a flag which tells the main loop that the user stopped pressing the button
00030             such that it can proceed its program.
00031         -   turns the built-in LED off. Therefore, the user gets informed that the program stopped counting the clicks.
00032 */
00033 void button1_multiclick_reset_cb(void) 
00034 {
00035     button1_busy = false;
00036     multiclick_state = click_counter;
00037     click_counter = 0;    
00038     led1 = 0;
00039 }
00040 
00041 /**
00042     TODO
00043     ----
00044     This function enables the button again, such that unwanted clicks of the bouncing button get ignored.
00045 */
00046 void button1_enabled_cb(void)
00047 {
00048     button1_enabled = true;
00049 }
00050 
00051 /**
00052     TODO
00053     ----
00054     This function:
00055         -   turns the built-in LED on, so the user gets informed that the program has started with counting clicks
00056         -   disables the button such that the debouncer is active
00057         -   enables the button again after a certain amount of time 
00058             (use interrupts with "button1_enabled_cb()" as callback.
00059         -   counts the amount of clicks within a period of 1 second
00060         -   informs the main loop that the button has been pressed
00061         -   informs the main loop that the user is clicking the button.
00062             Therefore, this main loop cannot continue its procedure until the clicks within 1 second have been counted.
00063 */
00064 void button1_onpressed_cb(void)
00065 {
00066     if(!button1_busy)
00067     {
00068         multiclick.attach( &button1_multiclick_reset_cb, 1 );
00069     }
00070     button1_busy = true;
00071     led1 = 1;
00072     if( button1_enabled )
00073     {
00074         button1_enabled = false;
00075         click_counter++;
00076         debounce.attach( &button1_enabled_cb, 0.08 ); // 80ms   
00077     }
00078 }