/*----------------------------------------
CDLEA_Main.c

電腦音源切換控制器
	用AT89C251+CD4016切換控制，可控制四路以上
的立體音源輸入切換，一路立體聲輸出,有紅外遙
控(SAA3010T電視遙控器，只處理四個音源)

Copyright 2003 http://cdle.yeha.net 
               http://cdle.126.com
All rights reserved.		
		明浩 E-mail: pnzwzw@163.com
----------------------------------------*/

#include <AT892051.h>

static unsigned char data CS;
static unsigned char data IRCode[4],IRCON,IRCON2;

void main(void)
{
	unsigned int de;
	void InitCom(unsigned char BaudRate);
	void ComOutChar(unsigned char OutData);
	void CSToOut(void);

	InitCom(6); //設置波特率為9600 1-7波特率300－19200
	EA = 1;	//允許CPU中斷
	ES = 1;	//開串口中斷
	IT0 = 1; //INT0下降沿有效
	EX0 = 1; //開INT0中斷
	CS = 0; //設置CS為0不選任何的音源，如為1則選第1路
	CSToOut();
	do
		{	
			if (P1_0 == 0)  //取按鍵值
				{
					CS = 1;
					P1 = 255; //P1口全為高電平，4-7通過反相為低不選任何音源，0-3為高用于
					CSToOut();
				}
			if (P1_1 == 0)
				{
					CS = 2;
					P1 = 255;
					CSToOut();
				}
			if (P1_2 == 0)
				{
					CS = 3;
					P1 = 255;
					CSToOut();
				}
			if (P1_3 == 0)
				{
					CS = 4;
					P1 = 255;
					CSToOut();
				}
			for (de=0; de<4000; de++);
		}
	while(1);
}


//串口初始化 晶振為11.0592M　方式1 波特率300-57600
void InitCom(unsigned char BaudRate)
{
	unsigned char THTL;
	switch (BaudRate)
		{
			case 1: THTL = 64; break; //波特率300
			case 2: THTL = 160; break; //600
			case 3: THTL = 208; break; //1200
			case 4: THTL = 232; break; //2400
			case 5: THTL = 244; break; //4800
			case 6: THTL = 250; break; //9600
			case 7: THTL = 253; break; //19200
			case 8: THTL = 255; break; //57600
			default: THTL = 208;
		}
	SCON = 0x50; //串口方式1,允許接收
	TMOD = 0x21; //定時器1定時方式2定時器0方式1　用在別處可以不用定時器0,TMOD=0x20
	TCON = 0x40; //設定時器1開始計數
	TH1 = THTL;
	TL1 = THTL;
	PCON = 0x80; //波特率加倍控制,SMOD位
	RI = 0;	//清收發標志
	TI = 0;
	TR1 = 1; //啟動定時器
}

//向串口輸出一個字符（非中斷方式）
void ComOutChar(unsigned char OutData)
{
	SBUF = OutData; //輸出字符
	while(!TI); //空語句判斷字符是否發完
	TI = 0; //清TI
}

//串口接收中斷
void ComInINT(void) interrupt 4 using 1
{
	if (RI) //判斷是不收完字符
		{
			switch(SBUF)
				{
				  case 0x61: CS = 1; break; //根據SBUF設置CS　接收'abcde'調試方便
					case 0x62: CS = 2; break;
					case 0x63: CS = 3; break;
					case 0x64: CS = 4; break;
					case 0x65: CS = 0; break;
				}
			P1 = 255; //P1口全為高電平，4-7通過反相為低不選任何音源，0-3為高用于讀取按鍵
			RI = 0; //RI清零
			CSToOut();
		}
}

//定時器0中斷處理
void timeint(void) interrupt 1 using 2
{
  //unsigned char a;
  TH0=0xFD;
  TL0=0x1E; //設定時值為800us

	if (IRCON<3)
    {
      if (IRCON2<8) //每中斷一次讀一次遙控接收頭的狀態,每二次為遙控編碼中的一個位
        {
          IRCON2++;
		      IRCode[IRCON]=IRCode[IRCON]<<1; //每讀一次放入變量中的二進制的一個位，每次左移一位
		      IRCode[IRCON]=IRCode[IRCON] | P3_2; //每八次填滿一個字節，一個字節存放遙控編碼4個位
        }
      else
        {
          IRCON++; //第填滿一個字節，指向下一個變量
          IRCON2=0; //計數清零
        }
    }
 else
  {
		TR0 = 0; //關閉定時器
		ET0 = 0; //定時器0中斷關閉
		//for (a=0;a<3;a++)
			//ComOutChar(IRCode[a]); //這兩句可通過PC串口調試軟件看接收到的數據，測試用
    if ((IRCode[1] == 0x55) && (IRCode[2] == 0xAB)) //取遙控值,取變量中的2,3字節
			{                        //第一字節是引導碼，第二、三字節是起始位、控制位和系統碼
				CS = 1;               
				P1 = 255;
				CSToOut();
				}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0xAC))
			{
				CS = 2;
				P1 = 255;
				CSToOut();
			}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0xAD))
			{
				CS = 3;
				P1 = 255;
				CSToOut();
			}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0xB2))
			{
				CS = 4;
				P1 = 255;
				CSToOut();
			}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0xD2)) //關閉
			{
				CS = 0;
				P1 = 255;
				CSToOut(); 
			}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0xD3)) //靜音
			{
				ComOutChar(8);
			}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0x2A)) //音量控制+
			{
				ComOutChar(6);
			}
		if ((IRCode[1] == 0x55) && (IRCode[2] == 0x2B)) //音量控制-
			{
				ComOutChar(7);
			}
		ES = 1; //打開串口中斷
		EX0 = 1; //打開
	} 
}

//INT0中斷
void INT0Fun(void) interrupt 0 using 2
{
	ES = 0; //串口中斷關閉
  EX0 = 0; //外部中斷0關閉
  ET0 = 1; //定時器0中斷打開
  TH0=0xFD;
  TL0=0x1E; //設定時值為800us
  
	for (IRCON=0; IRCON<3; IRCON++)
		IRCode[IRCON] = 0;
	IRCON = 0;
	IRCON2 = 0; //計數清零

	TR0 = 1;//開始計數
}

//根據全局變量輸出相應的控制信號
void CSToOut(void)
{
	P3_3 = 0;
	P3_4 = 0;
	P3_5 = 0;
	P3_7 = 0; //用P3=0則燒到片上無法運行，原因不明，可能串口P3_0,P3_1有關
	switch(CS)
		{
			case 0:
				P1 = 255; //P1口全為高電平，0-3通過反相為低不選任何音源，4-7為高用于讀取按鍵
				ComOutChar(5); //發0x05到PC
				break;
			case 1:
				P1_4 = 0; //為0反相后高電平選指定的音源
				P3_3 = 1;
				ComOutChar(1);
				break;
			case 2:
				P1_5 = 0;
				P3_4 = 1;
				ComOutChar(2);
				break;
			case 3:
				P1_6 = 0;
				P3_5 = 1;
				ComOutChar(3);
				break;
			case 4:
				P1_7 = 0;
				P3_7 = 1;
				ComOutChar(4);
				break;
		}
}