霓虹燈的電路圖:

霓虹燈的51單片機程序:
#include <reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit  RED_LED  = P1^0;            //端口定義.
sbit  GREEN_LED  = P1^1;
sbit  YELLOW_LED  = P1^2;
uint flicker,i,n;
void int0()
 {
   TMOD=0x01;
   TH0=0x3C;
   TL0=0xAF;
   TR0=1;    //啟動定時器。
   ET0=1;    //開定時器中斷.
   EA=1;    //開總中斷
 }
void main()      //主函數(shù)。
{ 
  n=0;
  i=0;
  GREEN_LED=1;
  YELLOW_LED=1;
  flicker=0;
  int0();
 while(1)
 {
  if(0<=n&&n<20)
      {
        YELLOW_LED=1;
        GREEN_LED=1;
        RED_LED=flicker;
      }
  if(20<=n&&n<40)
      {
         RED_LED=1;
         YELLOW_LED=1;
         GREEN_LED=flicker;
      }
  if(40<=n&&n<60)
      {
         RED_LED=1;
         GREEN_LED=1;
         YELLOW_LED=flicker;
         if(n==59)
          n=0;
      }
   }
}
void Time0() interrupt 1
{
 TR0=0;
 i++;
 if(i==10)
  {
   flicker=~flicker;
   i=0;
   n++;
  }
 TH0=0x3C;
 TL0=0xAF;
 TR0=1;
}
下面是另一個用51單片機的霓虹燈2:
如果網頁復制的代碼無法編譯成功可以從:http://m.izizhuan.cn/f/nhddpj_c.rar 這個鏈接下載
#include <reg52.h>
#define uchar unsigned char
#define uint unsigned int
uchar ss[]={0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,
            0x00,0xff,0x00,0xff,0x00,0x01,0x03,0x06,
            0x0c,0x18,0x30,0x60,0xc0,0x80,0x00,0xff,
   0x00,0xff,0x00,0xff,0x00,0x01,0x03,0x07,
   0x0e,0x1c,0x38,0x70,0xe0,0xc0,0x80,0x00,
   0xff,0x00,0xff,0x00,0x01,0x03,0x07,0x0f,
            0x1e,0x3c,0x78,0xf0,0xe0,0xc0,0x80,0xff,
   0x00,0xff,0x00,0xff,0x00,0x78,0xf0,0xff,
   0x00,0xff,0x00,0x80,0x40,0x20,0x10,0x08,
   0x04,0x02,0x01,0xff,0x00,0xff,0x00,0xff,
   0x00,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,
   0xff,0x7f,0x3f,0x1f,0x0f,0x07,0x03,0x01};
 /*數(shù)組中為霓虹燈閃爍花樣，單流水，雙流水，三流水，四流水和倒流*/
uint m,n,i;
void delay(m)
{
  while(m--)
   for(i=0;i<120;i++);
}
void main()      //主函數(shù)。
{  
 while(1)
 {
  P1=ss[n];
  P3=ss[n];
  delay(400);
  P1=0x00;
    n++;
  if(n==96)
    n=0;
 }
}