設(shè)計(jì)要求：
實(shí)現(xiàn)與Proteus中的8051單片機(jī)進(jìn)行串行通信。先回顧一下串行通信。在串行通信中有兩個(gè)引腳分別稱(chēng)為TX和RX。TX引腳用于發(fā)送數(shù)據(jù)，而RX引腳用于接收數(shù)據(jù)。
8051微控制器具有這兩個(gè)引腳，因此它支持串行通信，并且這些引腳位于AT89C52微控制器的10號(hào)和11號(hào)引腳上。
首先，將對(duì)此項(xiàng)目進(jìn)行原理圖設(shè)計(jì)（如下圖），在端口1上連接8個(gè)LED，并通過(guò)串行端口發(fā)送字符來(lái)打開(kāi)或關(guān)閉這些LED。設(shè)計(jì)完原理圖之后，我們將為8051微控制器設(shè)計(jì)編程代碼，并測(cè)試結(jié)果。
#include <reg52.h> #define Baud_rate 0xFD // BAUD RATE 9600 void SerialInitialize(void); void SendByteSerially(unsigned char); void cct_init(void); sbit Appliance1 = P1^0; sbit Appliance2 = P1^1; sbit Appliance3 = P1^2; sbit Appliance4 = P1^3; sbit Appliance5 = P1^4; sbit Appliance6 = P1^5; sbit Appliance7 = P1^6; sbit Appliance8 = P1^7; void main() { cct_init(); SerialInitialize(); EA = 1; ES = 1; while(1) {;} } void cct_init(void) //initialize cct { P0 = 0x00; //not used P1 = 0x00; //Used for Appliances P2 = 0x00; //not used P3 = 0x03; //used for serial } void SerialInitialize(void) // INITIALIZE SERIAL PORT { TMOD = 0x20;// Timer 1 IN MODE 2 -AUTO RELOAD TO GENERATE BAUD RATE SCON = 0x50;// SERIAL MODE 1, 8-DATA BIT 1-START BIT, 1-STOP BIT, REN //ENABLED TH1 = Baud_rate;// LOAD BAUDRATE TO TIMER REGISTER TR1 = 1;// START TIMER } void SendByteSerially(unsigned char serialdata) { SBUF = serialdata; // LOAD DATA TO SERIAL BUFFER REGISTER while(TI == 0);// WAIT UNTIL TRANSMISSION TO COMPLETE TI = 0;// CLEAR TRANSMISSION INTERRUPT FLAG } void serial_ISR (void) interrupt 4 { //receive character char chr; if(RI==1) { chr = SBUF; RI = 0; } P0 = ~P0; //Show the data has been updated switch(chr) { case '1': Appliance1 = 1; SendByteSerially('k'); break; case '2': Appliance2 = 1; SendByteSerially('k'); break; case '3': Appliance3 = 1; SendByteSerially('k');break; case '4': Appliance4 = 1; SendByteSerially('k'); break; case '5': Appliance5 = 1; SendByteSerially('k'); break; case '6': Appliance6 = 1; SendByteSerially('k'); break; case '7': Appliance7 = 1; SendByteSerially('k'); break; case '8': Appliance8 = 1; SendByteSerially('k'); break; case 'a': Appliance1 = 0; SendByteSerially('k'); break; case 'b':Appliance2 = 0; SendByteSerially('k'); break; case 'c': Appliance3 = 0; SendByteSerially('k'); break; case 'd': Appliance4 = 0; SendByteSerially('k'); break; case 'e': Appliance5 = 0; SendByteSerially('k'); break; case 'f': Appliance6 = 0; SendByteSerially('k'); break; case 'g': Appliance7 = 0; SendByteSerially('k'); break; case 'h': Appliance8 = 0; SendByteSerially('k'); break; default: ;break; //do nothing } RI = 0; }
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