/*#############################################################

Program Name    : ex1_extint_button_led
Author          : Grant Phillips
Date Modified   : 14/01/2016
Compiler        : ARMmbed
Tested On       : STM32F4-Discovery

Description     : Example to demostrate the use of an external
                  interrupt source and how it influences the 
                  flashing of an LED.    

Requirements    : * STM32F4-Discovery Board
              
Circuit         : * a pushbutton connected to PE8 with a 
                    pullup resitor
                  * a LED connected to PD8

##############################################################*/

#include "mbed.h"
 
InterruptIn button(PA_10);   //use PA_0 as an external interrupt

DigitalOut redled(PD_14);
DigitalOut blueled(PD_15);

/* function to be called for external interrupt (any name)*/
void toggle() {
    blueled = !blueled;     //invert old value of blueled and write new value to blueled (ie. toggle the led)
}
    
int main() {
    button.rise(&toggle);   //when the button goes HIGH (rise) at any time (interrupt), call the toggle function
                            //button.fall could also be used to detect going LOW
    while(1) {
        redled = !redled;   //toggle the red led
        //wait(1.0);          //even during the 1 sec wait will the toggle function be called due to the interrupt
        wait(0.2);
    }
}