/******************************************************************************
   Nome do Arquivo 	: main.c

   Descrição       	: Arquivo principal aula 11, exemplo 1

   Ambiente			    : WOKWI e RP2040 C/C++ SDK

   Responsável		  : Weslley M. Torres

   Versão/Data		  : 1.0.0 - 07/05/2024 - Initial version

 *****************************************************************************/

/******************************************************************************
  HEADER-FILES (Somente os arquivos necessários nesse arquivo)
******************************************************************************/
#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include "hardware/timer.h"
#include "hardware/irq.h"

/*****************************************************************************/

/******************************************************************************
  Variaveis Globais
******************************************************************************/
#define OUT_H 1
#define OUT_L 0

#define LED 28
#define OUT 1
#define IN 0

// Low-level alarm infrastructure we'll be using
#define ALARM_NUM 0
#define ALARM_IRQ TIMER_IRQ_0

#define DELAY 1000000 // 1/Fs (in microseconds)
/*****************************************************************************/

/******************************************************************************
  Prototipos das funções
******************************************************************************/
void system_init(void);
void alarm_irq() ;
/*****************************************************************************/

/******************************************************************************
   Funcao:		void alarm_irq(void) 
   Entrada:		Nenhuma (void)
   Saída:		  Nenhuma (void)
   Descrição:	Função tratamento interrupcao do timer 0
 *****************************************************************************/
void alarm_irq(void) 
{
  static bool toggle = false;
  printf("Timer interrupt occurred!\n");
  // Clear the alarm irq
  hw_clear_bits(&timer_hw->intr, 1u << ALARM_NUM);

  uint64_t target = timer_hw->timerawl + DELAY;

  // Write the lower 32 bits of the target time to the alarm register, arming it.
  timer_hw->alarm[ALARM_NUM] = (uint32_t) target;

  // Toggle an LED or do some other processing
  // For example, toggle an LED on GPIO 28
  gpio_put(LED, toggle);
  toggle = !toggle;
}


/******************************************************************************
   Funcao:		int main(void)
   Entrada:		Nenhuma (void)
   Saída:		Nenhuma (void)
   Descrição:	Função principal
 *****************************************************************************/
int main() 
{
  stdio_init_all();
  system_init();

  printf("Hello, Timer!\n");
  sleep_ms(250);

  while(true)
  {

  }

}

/******************************************************************************
   Funcao:		void system_init(void)
   Entrada:		Nenhuma (void)
   Saída:		Nenhuma (void)
   Descrição:	Inicializa sistema (microcontrolador e periféricos)
 *****************************************************************************/
void system_init(void)
{ 
  uint64_t target = 0;

  gpio_init(LED);
  gpio_set_dir(LED, OUT);

  // Enable the interrupt for the alarm (we're using Alarm 0)
  hw_set_bits(&timer_hw->inte, 1u << ALARM_NUM) ;
  // Associate an interrupt handler with the ALARM_IRQ
  irq_set_exclusive_handler(ALARM_IRQ, alarm_irq) ;
  // Enable the alarm interrupt
  irq_set_enabled(ALARM_IRQ, true) ;
  
  target = timer_hw->timerawl + DELAY;

  // Write the lower 32 bits of the target time to the alarm register, arming it.
  timer_hw->alarm[ALARM_NUM] = (uint32_t) target;
}