led_flash.c

来自「Embedded C 这本书的范例光碟程式」· C语言 代码 · 共 50 行

/*
  LED_flash.C (v1.00)
  Simple 'Flash LED' test function.
*/

#include "Main.H"
#include "Port.H"

#include "LED_flash.H"

// ------ Private variable definitions -----------------------------

static bit LED_state_G;

/*
  LED_FLASH_Init()
  Prepare for LED_Change_State() function - see below.
*/
void LED_FLASH_Init(void)
{
   LED_state_G = 0;
}

/*
  LED_FLASH_Change_State()
  Changes the state of an LED (or pulses a buzzer, etc) on a 
  specified port pin.
  Must call at twice the required flash rate: thus, for 1 Hz
  flash (on for 0.5 seconds, off for 0.5 seconds) must call
  every 0.5 seconds.
*/
void LED_FLASH_Change_State(void)
{
   // Change the LED from OFF to ON (or vice versa)
   if (LED_state_G == 1)
   {
      LED_state_G = 0;
      LED_pin = 0;
   }
   else
   {
      LED_state_G = 1;
      LED_pin = 1;
      }
}

/*------------------------------------------------------------------*-
  ---- END OF FILE -------------------------------------------------
-*------------------------------------------------------------------*/