12-串行接口的进阶应用

串行接口的进阶应用

由上可知：

​ 应用高四位来判断控制灯光，所以应用高四位对比，将第四位置0进行对比用switch语句，

进行判断，将为A时，保留低四位，取反将高四位置1

​ 将为B时，保留高四位，取反将低四位置1，向左移动4位

#include <REGX52.H>
sfr AUXR = 0x8E;


unsigned char command = 0x00;
void _74HC138(unsigned char n) {
	
	
	
	switch(n) {
		case 4:
			P2 = (P2 & 0x1f) | 0x80;
			break;
		case 5:
			P2 = (P2 & 0x1f) | 0xa0;
			break;
		case 6:
			P2 = (P2 & 0x1f) | 0xc0;
			break;
		case 7:
			P2 = (P2 & 0x1f) | 0xe0;
			break;
	
	}

} 



void System_Init(void) {
	_74HC138(5);
	P0 = 0x00;
	_74HC138(4);
	P0 = 0xFF;
	

}


void UART_Init(void) {
	
	TMOD = 0X20;
	SCON = 0X50;
	TL1= 0XFD;
	TH1= 0XFD;
	AUXR = 0x00;
	
	TR1 = 1;
	ES = 1;
	EA = 1;
	
	
}

void SendByte(unsigned char dat) {
	SBUF = dat;
	while(TI == 0);
	TI = 0;

}
void sendString(unsigned char *Str) {
	while(*Str !='\0') {
		SendByte(*Str++); 
	}

}

void work() {
	_74HC138(4);
	if(command != 0) {
		
		switch(command & 0xf0) 
			{// 1111 0000
			case 0xA0:
				P0 = 0XFF;  // 
				P0 = (P0 | 0x0F) & (~command | 0xF0);
				command = 0x00;
			break;
			case 0xB0:
				P0 = 0XFF;
				P0 = (P0 | 0XF0) & (~command << 4 | 0x0F);
				command = 0x00;
			break;
			case 0xC0:
				sendString("The System is running...");
				command = 0x00;
			break;
		}
	}
}

void main(void) {
	System_Init();
	UART_Init();

	sendString("Wecome to xxx System...\t\n");
	
	while(1) {
		work();
	}
}

void UART1_Routine(void) interrupt 4{
	if(RI == 1) {
		command = SBUF;
		
		RI = 0;
	}

}