/* Configure the push button. 
Configure the PIOs as inputs and generate corresponding interrupt when pressed or released.  */
static void configure_button(void)
/* Configure the push button. 
Configure the PIOs as inputs and generate corresponding interrupt when pressed or released.  */
static void configure_button(void)
{
	pmc_enable_periph_clk(PUSH_BUTTON_ID);
	pio_set_debounce_filter(PUSH_BUTTON_PIO, PUSH_BUTTON_PIN_MSK, 10);
	pio_handler_set(PUSH_BUTTON_PIO, PUSH_BUTTON_ID, PUSH_BUTTON_PIN_MSK,
		PUSH_BUTTON_ATTR, button_handler);
	NVIC_EnableIRQ((IRQn_Type)PUSH_BUTTON_ID);
	pio_enable_interrupt(PUSH_BUTTON_PIO, PUSH_BUTTON_PIN_MSK);
}