//智能顯示終端串口(Uart)通信演示程序。
//
#include <reg51.h>
#include <stdio.h>
#include <string.h>
#define uchar unsigned char

uchar  Fcolor;                 //背景色
uchar  Bcolor;                 //前景色

Lcd_Clr();
dis_wave(unsigned short x0,unsigned short y0,uchar con,unsigned short *p_data);

/********************************************
定義數據常量，這些數據在實際應用中一般由A/D轉換器采樣所得到。
這里的每一個字節代表一個Y軸坐標的大小即幅度。
**********************************************/
unsigned short code y_data1[110] = {
  0x0b,0x0b,0x0b,0x0b,0x0b,
  0x0b,0x0b,0x0b,0x0b,0x0b,
  0x0b,0x0b,0x0b,0x0b,0x0b,
  0x1c,0x1c,0x1c,0x1c,0x1c,
  0x1c,0x1c,0x1c,0x1c,0x1c,
  0x1c,0x1c,0x1c,0x1c,0x1c,
  0x1c,0x1c,0x1c,0x1c,0x1c,
  0x00,0x00,0x00,0x00,0x00,
  0x00,0x00,0x00,0x00,0x00,
  0x00,0x00,0x00,0x00,0x00,
  0x00,0x00,0x00,0x00,0x00,
  0x50,0x50,0x50,0x50,0x50,
  0x50,0x50,0x50,0x50,0x50,
  0x50,0x50,0x50,0x50,0x50,
  0x50,0x50,0x50,0x50,0x50,
  0x50,0x50,0x50,0x50,0x50,
  0x48,0x46,0x44,0x42,0x40,
  0x3e,0x3c,0x3a,0x38,0x36,
  0x34,0x32,0x30,0x2e,0x2c,
  0x2a,0x28,0x26,0x24,0x22,
  0x20,0x1e,0x1c,0x1a,0x18,
  0x16,0x14,0x12,0x10,0x84
  };

unsigned short code y_data2[110] = {
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x015e,0x015e,0x015e,0x015e,0x015e,
  0x00,0x00,0x00,0x00,0x00,
  0x00,0x00,0x00,0x00,0x00,
  0x00,0x00,0x00,0x00,0x00,
  0x00,0x00,0x00,0x00,0x00,
  0x0084,0x0084,0x0084,0x0084,0x0084,
  0x0084,0x0084,0x0084,0x0084,0x0084,
  0x0084,0x0084,0x0084,0x0084,0x0084,
  0x0084,0x0084,0x0084,0x0084,0x0084,
  0x0084,0x0084,0x0084,0x0084,0x0084,
  0x48,0x46,0x44,0x42,0x40,
  0x3e,0x3c,0x3a,0x38,0x36,
  0x34,0x32,0x30,0x2e,0x2c,
  0x2a,0x28,0x26,0x24,0x22,
  0x20,0x1e,0x1c,0x1a,0x18,
  0x16,0x14,0x12,0x10,0xffff
  };
 
main(void)
{
  unsigned int i;

//對AT89C51(11.059MHz)的串口初始化
  TMOD=0x20;                              //定時器1設置為模式2
  SM0=0;
  SM1=1;                                  //設置串口為方式1，10位異步收發
  PCON=PCON|0x80;                         //波特率加倍
  TL1=0xFD;
  TH1=0xFD;                               //波特率為19200
  TR1=1;                                  //啟動定時器1
  REN = 1;                                //允許串口接受使能

  //EA=1;                                   //全局中斷使能，(EA=0,關全局中斷；EA=1，開全局中斷）
  //ES = 1;                                 //串口中斷使能置1，允許串口中斷

  Fcolor = 0x0;
  Bcolor = 0xff;
  i = 0;

  //顯示終端在上電就緒時發送F0.用仿真器時不要檢測F0.
  //當把程序燒寫到單片機上時，顯示終端和單片機同時上電，所以一定
  //要檢測是否收到F0。以判斷顯示終端是否上電就緒
  //while(!(i == 0xF0))
  //{i = SBUF;} 

  Lcd_Clr();     //清除全屏。
  Fcolor = 0xe0;
  dis_wave(0,0,1,y_data1);     //以 (0,0) 為坐標原點顯示波形。幅度為單字節
  Fcolor = 0x1c;
  dis_wave(100,100,2,y_data2);    //以 (80,80) 為坐標原點顯示波形。幅度為雙字節。
  Fcolor = 0xff;
  while(1);
}

//查看一個字符是否傳送完畢，當一個字符傳送完畢后TI位會被硬件置1；
void check_uart(void)
{
  while(TI==0)
  {}
   TI=0;
}
//指令頭，每一條指令都規定為"0x81, command1,command2,Fcolor,Bcolor"
command_head(unsigned char command1,unsigned char command2)
{
   TI=0;
   SBUF= 0x81;
   check_uart();
   SBUF= command1;
   check_uart();
   SBUF= command2;
   check_uart();

   SBUF= Fcolor;
   check_uart();
   SBUF= Bcolor;
   check_uart();
}
//指令頭+x0+y0
command_head2(uchar command1,uchar command2,unsigned short x0,unsigned short y0)
{
   command_head(command1,command2);

   SBUF= x0/100;
   check_uart();
   SBUF= x0%100;
   check_uart();
   SBUF= y0/100;
   check_uart();
   SBUF= y0%100;
   check_uart();
}

//清屏子程序
Lcd_Clr()
{
   command_head(0x43,0x4c);
   SBUF= 0x84;
   check_uart();
}

//顯示波形子程序。
//顯示波形的原理是：x軸從坐標原點開始自動加一，y軸(幅度)是*p_data。
//x0, y0是坐標原點。
//con=1 y軸(幅度)的大小用一個字節表示。con = 2:y軸(幅度)的大小用二個字節表示
dis_wave(unsigned short x0,unsigned short y0,uchar con,unsigned short *p_data)
{
   command_head2(0x53,0x53,x0,y0);
   SBUF= con;
   check_uart();
   switch(con)
      {case 1:
   		   do
   		   {
      	    SBUF = (*p_data%100);    //因為*p_data定義為short類型指針，所以這里要先取模運算再發送
			check_uart();
			p_data++;
   	  	   }
   		   while(*p_data !=0x84);
	    break;

		case 2:
		    do
			{
			 SBUF=(*p_data/100);
			 check_uart();
			 SBUF=(*p_data%100);
			 check_uart();
			 p_data++;
			}
			while(*p_data !=0xffff);   //這里不能定義為Ox84，因為p_data[x]有可能是0x84
		break;

		default: break;
	  }
   SBUF=(0x84);
   check_uart();
}