PIC16F877A TMR0使用

用C语言写的一个PIC16F877的时闹钟程序单片机用16F877，主时钟用20MHz，用32768作定时时间。

可以实现2路定闹，每一路都可分别设置和开关，采用4x4键盘，16x2的字符型LCD显示。

连线在程序开头有说明。

程序的功能：（1）上电后LCD背光打开，并显示倒计时5秒，然后时钟开始工作。

（2）用模式键（*）切换模式，如显示时间、日期、闹钟1、闹钟2等，并且可以用上、下键控制加1、减1或是闹钟的On、Off。

（3）原程序有16个键，包括0~9数字键，可以直接输入要设置的时间值，但后来将数字键取消了，你仍然可以通过修改程序的部分注释恢复此功能。

（4）闹钟有2路，时间到后闹2分钟，可按任意键取消本次闹钟。

闹钟响时有2种音调，是用PIC的PWM实现的。

（5）按任意键可打开背光，1分钟后自动关闭背光。

（6）RA0~RA3为按键扫描输入，应接下拉电阻。

主程序// FileName: Main.c// MCU: Microchip PIC16F877// Tool: CCS-C compiler// Author: KingEDA, MSN:kingeda@, skype:kingeda, E-mail:kingeda@// Website: // Description:// A timer program// Ver 0.1: 2003-03-31, all clock function with date display, 2 way alarm.// Ver 0.2: 2003-05-05, (1) Alarm default is on,modify alarm1 time to 7:00:00,// and alarm2 to 13:30:00.// (2) Backlight will be enabled when alarming.// (3) Automatic adjust day(28,30,31).// (4) Automatic move cursor to next location when set item.// PIN Connection:// RC0~1 : 32768Hz crystal// RC2 : Buzzer// RC3 : LCD Back Light,drive a PNP BJT// RD0~RD7 : to LCD DB0~DB7// RA0~RA3 : keypad col in// RC4~RC7 : keypad line out// 7 8 9 #// 4 5 6 ↑// 1 2 3 ↓// 0 ←→*// RE0 : LCD RS// RE1 : LCD RW// RE2 : LCD E#include "my16f877.h"#device ICD=true//#fuses HS,NOWDT,NOPROTECT,PUT,BROWNOUT #use delay(clock = 24000000)//#use fast_io(C)#use fast_io(E)#define lcd_busy (lcd_read_addr()&0x80) == 0x80#define time_start_addr 0x80+0x04#define time_hourh_addr time_start_addr#define time_hourl_addr time_start_addr+1#define time_minuteh_addr time_start_addr+3#define time_minutel_addr time_start_addr+4#define time_secondh_addr time_start_addr+6#define time_secondl_addr time_start_addr+7#define key_0 0x11#define key_1 0x21#define key_2 0x22#define key_3 0x24#define key_4 0x41#define key_5 0x42#define key_6 0x44#define key_7 0x81#define key_8 0x82#define key_9 0x84#define key_left 0x12#define key_right 0x14#define key_up 0x48#define key_down 0x28#define key_mode 0x18#define key_cancel 0x88char StrPower1[] = " * Power on * ";char StrSetTime[] = " * Adjust time* ";char StrSetDate[] = " * Adjust date* ";char StrAlarm1[] = " * Set alarm 1* ";char StrAlarm2[] = " * Set alarm 2* ";unsigned char PORTC_MAP;#bit BackLightEn = PORTC_MAP.3unsigned char BackLightTimer;int1 led;#bit lcd_rs = PORTE.0#bit lcd_rw = PORTE.1#bit lcd_e = PORTE.2#byte lcd_bus = PORTD#byte lcd_dir = TRISD#define PWM_on 0x0c#define PWM_off 0x00#define PWM_period 200#define PWM_DC 100unsigned char lcd_addr;unsigned char KeyLine;unsigned char KeyOld;unsigned char KeyNew;struct mTime {unsigned char hourh; // hour,0~23unsigned char hourl;unsigned char minuteh; // minute,0~59unsigned char minutel;unsigned char secondh; // second,0~59unsigned char secondl;};struct mTime CurrentTime = {1,2,0,0,0,0};struct mTime AlarmTime1 = {0,7,0,0,0,0}; // 07:00:00 struct mTime AlarmTime2 = {1,3,3,0,0,0}; // 13:30:00 unsigned char AlarmStatus;#bit Alarm1Enable = AlarmStatus.0#bit Alarm2Enable = AlarmStatus.1#bit Alarm1Alarm = AlarmStatus.2#bit Alarm2Alarm = AlarmStatus.3unsigned char Alarm1Cnt; // alarm1 second count unsigned char Alarm2Cnt;unsigned char CurrentMode;#define mode_time 0#define mode_set_time 1#define mode_set_date 2#define mode_set_alarm1 3#define mode_set_alarm2 4unsigned char adjust_item;struct mDate {unsigned char year1; //unsigned char year2;unsigned char year3;unsigned char year4;unsigned char monthh;unsigned char monthl;unsigned char dayh;unsigned char dayl;};struct mDate CurrentDate = {2,0,0,3,0,1,0,1}; unsigned char *pStr;// ------------------------------------------------------- unsigned char lcd_read_addr(){unsigned char ch;lcd_dir = 0xff; // read from lcdlcd_rs = 0;lcd_rw = 1; // instlcd_e = 1;#asmnopnopnop#endasmch = lcd_bus;lcd_e = 0;lcd_dir = 0x00; // set write to lcdreturn ch;}// ------------------------------------------------------- unsigned char lcd_write_data(unsigned char ch) {while (lcd_busy){ restart_wdt(); }lcd_rs = 1; // datalcd_rw = 0; // writelcd_bus = ch; // write outlcd_e = 1;#asmnopnopnop#endasmlcd_e = 0;return 'Y';}// ------------------------------------------------------- unsigned char lcd_write_inst(unsigned char ch) {while (lcd_busy){ restart_wdt(); }lcd_rs = 0; // instlcd_rw = 0; // writelcd_bus = ch;lcd_e = 1;#asmnopnopnop#endasmlcd_e = 0;return 'Y';}// ------------------------------------------------------- unsigned char lcd_read_data(){unsigned char ch;while (lcd_busy){ restart_wdt(); }lcd_dir = 0xff; // read from lcdlcd_rs = 1; // datalcd_rw = 1; // readlcd_e = 1;#asmnopnopnop#endasmch = lcd_bus; // read inlcd_e = 0;lcd_dir = 0x00; // set write to lcdreturn ch;}// ------------------------------------------------------- void lcd_init(){unsigned char Tempch;lcd_addr = 0;delay_ms(100);Tempch = 0x38; // 1-line mode,5x8 dotslcd_write_inst(Tempch); // Function setTempch = 0x0f; // lcd on,cursor on,blink onlcd_write_inst(Tempch); // Display on/offTempch = 0x06; // Increment mode,Entire shift offlcd_write_inst(Tempch);Tempch = 0x01; // clear displaylcd_write_inst(Tempch);delay_ms(3);}// -------------------------------------------------------//#int_timer1//void timer1_interrupt(void)#int_ccp2void ccp2_interrupt(void){//TMR1H = 0x80;if (CurrentTime.secondl==9){CurrentTime.secondl=0;if (CurrentTime.secondh==5){CurrentTime.secondh=0;if (CurrentTime.minutel==9){CurrentTime.minutel=0;if (CurrentTime.minuteh==5){CurrentTime.minuteh=0;if (CurrentTime.hourl==9){CurrentTime.hourl=0;CurrentTime.hourh++;}else if((CurrentTime.hourl==3) && (CurrentTime.hourh==2)){CurrentTime.hourl=0;CurrentTime.hourh=0;if ((((CurrentDate.dayl == 8) || (CurrentDate.dayl == 9)) && (CurrentDate.dayh == 2) && (CurrentDate.monthl == 2) && (CurrentDate.monthh == 0)) ||((CurrentDate.dayl == 0) && (CurrentDate.dayh == 3) && ((((CurrentDate.monthl == 4) || (CurrentDate.monthl == 6)|| (CurrentDate.monthl == 9)) && (CurrentDate.monthh == 0)) || ((CurrentDate.monthl == 1) && (CurrentDate.monthh == 1)))) ||((CurrentDate.dayl == 1) && (CurrentDate.dayh == 3))){CurrentDate.dayl=1;CurrentDate.dayh=0;if ((CurrentDate.monthl == 2) && (CurrentDate.monthh == 1)){CurrentDate.monthl = 1;CurrentDate.monthh = 0;if (CurrentDate.year4 == 9){CurrentDate.year4 = 0;if (CurrentDate.year3 == 9){CurrentDate.year3 = 0;if (CurrentDate.year2 == 9){CurrentDate.year2 = 0;CurrentDate.year1++;}elseCurrentDate.year2++;}elseCurrentDate.year3++;}elseCurrentDate.year4++;}else if(CurrentDate.monthl == 9){CurrentDate.monthl = 0;CurrentDate.monthh++;}elseCurrentDate.monthl++;}else if(CurrentDate.dayl == 9){CurrentDate.dayl=0;CurrentDate.dayh++;}elseCurrentDate.dayl++;}elseCurrentTime.hourl++;}elseCurrentTime.minuteh++;}elseCurrentTime.minutel++;}elseCurrentTime.secondh++;}elseCurrentTime.secondl++;if ((Alarm1Alarm == false) & (Alarm2Alarm == false)){led = 0;CCP1CON = PWM_off;}else{if (led == 1){led = 0;PR2 = PWM_period; // set pwm periodCCPR1L = PWM_DC; // set pwm duty cycle//CCP1CON = PWM_on;}else{led = 1;PR2 = PWM_period/2; // set pwm periodCCPR1L = PWM_DC/2; // set pwm duty cycle//CCP1CON = PWM_off;}}Alarm1Cnt++;Alarm2Cnt++;if (BackLightEn == 0)if (((BackLightTimer++)>=60) & (Alarm1Alarm == false) & (Alarm1Alarm == false))BackLightEn = 1; // disable backlight PORTC = PORTC_MAP;//TMR1IF = 0;//PIR1 = PIR2 = 0x00;CCP2IF = 0;}// ------------------------------------------------------- unsigned char get_key(void){unsigned char key_in,tmp;TRISC = 0x03;KeyLine = 0xf0;PORTC = KeyLine | PORTC_MAP;#asmnopnopnop#endasmif ((PORTA & 0x0f) != 0){tmp = 0x10;for (KeyLine = tmp;KeyLine!=0;KeyLine = tmp){PORTC = KeyLine | PORTC_MAP;tmp = KeyLine <<1;#asmnopnopnop#endasmkey_in = PORTA & 0x0f;if (key_in != 0){return (key_in | KeyLine);}}return 0;}elsereturn 0;}// -------------------------------------------------------void set_mode(void){if (CurrentMode == mode_set_alarm2)CurrentMode = mode_time;else{CurrentMode++;adjust_item = 0;}lcd_write_inst(0x01); // clear LCD displaylcd_write_inst(time_start_addr); // set LCD line1 if (CurrentMode == mode_set_time){lcd_write_data(CurrentTime.hourh + '0');lcd_write_data(CurrentTime.hourl + '0');lcd_write_data(':');lcd_write_data(CurrentTime.minuteh + '0');lcd_write_data(CurrentTime.minutel + '0');lcd_write_data(':');lcd_write_data(CurrentTime.secondh + '0');lcd_write_data(CurrentTime.secondl + '0');pStr = StrSetTime;}else if(CurrentMode == mode_set_date){lcd_write_data(CurrentDate.year1 + '0');lcd_write_data(CurrentDate.year2 + '0');lcd_write_data(CurrentDate.year3 + '0');lcd_write_data(CurrentDate.year4 + '0');lcd_write_data('/');lcd_write_data(CurrentDate.monthh + '0');lcd_write_data(CurrentDate.monthl + '0');lcd_write_data('/');lcd_write_data(CurrentDate.dayh + '0');lcd_write_data(CurrentDate.dayl + '0');pStr = StrSetDate;}else if(CurrentMode == mode_set_alarm1){lcd_write_data(AlarmTime1.hourh + '0');lcd_write_data(AlarmTime1.hourl + '0');lcd_write_data(':');lcd_write_data(AlarmTime1.minuteh + '0');lcd_write_data(AlarmTime1.minutel + '0');lcd_write_data(':');lcd_write_data(AlarmTime1.secondh + '0');lcd_write_data(AlarmTime1.secondl + '0');lcd_write_data(' ');lcd_write_data('O');if (Alarm1Enable){lcd_write_data('n');}else{lcd_write_data('f');lcd_write_data('f');}pStr = StrAlarm1;Alarm1Cnt =0;}else if(CurrentMode == mode_set_alarm2) {lcd_write_data(AlarmTime2.hourh + '0');lcd_write_data(AlarmTime2.hourl + '0');lcd_write_data(':');lcd_write_data(AlarmTime2.minuteh + '0');lcd_write_data(AlarmTime2.minutel + '0');lcd_write_data(':');lcd_write_data(AlarmTime2.secondh + '0');lcd_write_data(AlarmTime2.secondl + '0');lcd_write_data(' ');lcd_write_data('O');if (Alarm2Enable){lcd_write_data('n');}else{lcd_write_data('f');lcd_write_data('f');}pStr = StrAlarm2;Alarm2Cnt = 0;}lcd_write_inst(0xc0); // set LCD line2 if (CurrentMode != mode_time){for (;*pStr!=0;pStr++){ // write hint messagelcd_write_data(*pStr);}lcd_write_inst(0x0f); // LCD cursor onlcd_write_inst(time_start_addr); // move cursor to start }else // time mode,write date to second line{lcd_write_inst(0x0c); // LCD sursor off/* lcd_write_inst(0xc0 + 3); // set date start address lcd_write_data(CurrentDate.year1 + '0');lcd_write_data(CurrentDate.year2 + '0');lcd_write_data(CurrentDate.year3 + '0');lcd_write_data(CurrentDate.year4 + '0');lcd_write_data('/');lcd_write_data(CurrentDate.monthh + '0');lcd_write_data(CurrentDate.monthl + '0');lcd_write_data('/');lcd_write_data(CurrentDate.dayh + '0');lcd_write_data(CurrentDate.dayl + '0');*/ }if (CurrentMode == mode_set_time){lcd_write_inst(time_start_addr); // move cursor to start }else if (CurrentMode == mode_set_date){lcd_write_inst(time_start_addr); // move cursor to start }else if (CurrentMode == mode_set_alarm1){lcd_write_inst(time_secondl_addr+3);adjust_item = 6;}else if (CurrentMode == mode_set_alarm2){lcd_write_inst(time_secondl_addr+3);adjust_item = 6;}else{lcd_write_inst(0x0c); // LCD cursor off}}// ------------------------------------------------------- void set_date(void){if (adjust_item == 0) // adjust year{if ((KeyNew >=0) & (KeyNew <= 9)){CurrentDate.year1 = KeyNew;lcd_write_data(CurrentDate.year1 + '0');//lcd_write_inst(time_start_addr);adjust_item ++;}else if (KeyNew == key_left){adjust_item = 7;lcd_write_inst(time_start_addr + 9);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 1);}}else if(adjust_item == 1){if ((KeyNew >=0) & (KeyNew <= 9)){CurrentDate.year2 = KeyNew;lcd_write_data(CurrentDate.year2 + '0');//lcd_write_inst(time_start_addr + 1);adjust_item ++;}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 0);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 2);}}else if(adjust_item == 2){if ((KeyNew >=0) & (KeyNew <= 9)){CurrentDate.year3 = KeyNew;lcd_write_data(CurrentDate.year3 + '0');//lcd_write_inst(time_start_addr + 2);adjust_item ++;}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 1);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 3);}}else if(adjust_item == 3){if ((KeyNew >=0) & (KeyNew <= 9)){CurrentDate.year4 = KeyNew;lcd_write_data(CurrentDate.year4 + '0');//lcd_write_inst(time_start_addr + 3);adjust_item ++;lcd_write_inst(time_start_addr + 5);}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 2);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 5);}}else if(adjust_item == 4)if (((CurrentDate.monthl>2) & (KeyNew == 0)) | ((CurrentDate.monthl == 0) & (KeyNew == 1))| (((CurrentDate.monthl == 1) | (CurrentDate.monthl == 2)) & (KeyNew <2))) {CurrentDate.monthh = KeyNew;lcd_write_data(CurrentDate.monthh + '0');//lcd_write_inst(time_start_addr + 5);adjust_item ++;}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 3);}else if (KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 6);}}else if(adjust_item == 5){if (((CurrentDate.monthh == 3) & (KeyNew <2)) | ((CurrentDate.monthh != 3) & (KeyNew >=0) & (KeyNew <=9))){CurrentDate.monthl = KeyNew;lcd_write_data(CurrentDate.monthl + '0');//lcd_write_inst(time_start_addr + 6);adjust_item ++;lcd_write_inst(time_start_addr + 8);}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 5);}else if (KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 8);}}else if(adjust_item == 6)if (((CurrentDate.dayl>1) & ((KeyNew == 1) | (KeyNew == 2))) | ((CurrentDate.dayl == 0) & (KeyNew >0) & (KeyNew<4))| ((CurrentDate.dayl == 1) & (KeyNew <4))){CurrentDate.dayh = KeyNew;lcd_write_data(CurrentDate.dayh + '0');//lcd_write_inst(time_start_addr + 8);adjust_item ++;}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 6);}else if (KeyNew == key_right){adjust_item ++;lcd_write_inst(time_start_addr + 9);}}else if(adjust_item == 7){if (((CurrentDate.dayh == 3) & (KeyNew <2)) | ((CurrentDate.dayh != 3) & (KeyNew >=0) & (KeyNew <=9))){CurrentDate.dayl = KeyNew;lcd_write_data(CurrentDate.dayl + '0');//lcd_write_inst(time_start_addr + 9);adjust_item ++;lcd_write_inst(time_start_addr + 0);}else if (KeyNew == key_left){adjust_item --;lcd_write_inst(time_start_addr + 8);}else if (KeyNew == key_right){adjust_item = 0;lcd_write_inst(time_start_addr + 0);}}}// -------------------------------------------------------void set_time(void){if (adjust_item == 0) // set hourh{if (((CurrentTime.hourl <4) & (KeyNew < 3)) | ((CurrentTime.hourl >3) & (KeyNew <2))){CurrentTime.hourh = KeyNew;lcd_write_data(CurrentTime.hourh + '0'); // refresh hourh//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item = 5;lcd_write_inst(time_secondl_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_hourl_addr);}}else if (adjust_item == 1) // set hourl{if (((CurrentTime.hourh == 2) & (KeyNew < 4)) | ((CurrentTime.hourh < 2) & (KeyNew <=9))){CurrentTime.hourl = KeyNew;lcd_write_data(CurrentTime.hourl + '0'); // refresh hourl//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_minuteh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_hourh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_minuteh_addr);}}else if (adjust_item == 2) // set minuteh{if (KeyNew <6){CurrentTime.minuteh = KeyNew;lcd_write_data(CurrentTime.minuteh + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_hourl_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_minutel_addr);}}else if (adjust_item == 3) // set minutel{if ((KeyNew >=0) & (KeyNew <=9)){CurrentTime.minutel = KeyNew;lcd_write_data(CurrentTime.minutel + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_secondh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_minuteh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondh_addr);}}else if (adjust_item == 4) // set secondh{if (KeyNew <6){CurrentTime.secondh = KeyNew;lcd_write_data(CurrentTime.secondh + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item --;&nb, sp; lcd_write_inst(time_minutel_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondl_addr);}}else if (adjust_item == 5) // set secondl{if ((KeyNew >=0) & (KeyNew <=9)){CurrentTime.secondl = KeyNew;lcd_write_data(CurrentTime.secondl + '0');//lcd_write_inst(0x10); // move cursor backadjust_item = 0;lcd_write_inst(time_hourh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_secondh_addr);}else if(KeyNew == key_right){adjust_item = 0;lcd_write_inst(time_hourh_addr);}}}// -------------------------------------------------------void set_alarm1(void){if (adjust_item == 0) // set hourh{if (((AlarmTime1.hourl <4) & (KeyNew < 3)) | ((AlarmTime1.hourl >3) & (KeyNew <2))){AlarmTime1.hourh = KeyNew;lcd_write_data(AlarmTime1.hourh + '0'); // refresh hourh//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item = 6;lcd_write_inst(time_secondl_addr + 3);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_hourl_addr);}}else if (adjust_item == 1) // set hourl{if (((AlarmTime1.hourh == 2) & (KeyNew < 4)) | ((AlarmTime1.hourh < 2) & (KeyNew <=9))){AlarmTime1.hourl = KeyNew;lcd_write_data(AlarmTime1.hourl + '0'); // refresh hourl//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_minuteh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_hourh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_minuteh_addr);}}else if (adjust_item == 2) // set minuteh{if (KeyNew <6){AlarmTime1.minuteh = KeyNew;lcd_write_data(AlarmTime1.minuteh + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_hourl_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_minutel_addr);}}else if (adjust_item == 3) // set minutel{if ((KeyNew >=0) & (KeyNew <=9)){AlarmTime1.minutel = KeyNew;lcd_write_data(AlarmTime1.minutel + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_secondh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_minuteh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondh_addr);}}else if (adjust_item == 4) // set secondh{if (KeyNew <6){AlarmTime1.secondh = KeyNew;lcd_write_data(AlarmTime1.secondh + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_minutel_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondl_addr);}}else if (adjust_item == 5) // set secondl{if ((KeyNew >=0) & (KeyNew <=9)){AlarmTime1.secondl = KeyNew;lcd_write_data(AlarmTime1.secondl + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_secondl_addr+3);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_secondh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondl_addr+3);}}else if (adjust_item == 6) // set on/off{if ((KeyNew == key_up) | (KeyNew == key_down)){if (Alarm1Enable){Alarm1Enable =false; // disable alarm1lcd_write_data('f');lcd_write_data('f');}else{Alarm1Enable =true; // enable alarm1lcd_write_data('n');lcd_write_data(' ');}//lcd_write_inst(time_secondl_addr+3);adjust_item = 0;lcd_write_inst(time_hourh_addr);Alarm1Cnt = 0;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_secondl_addr);}else if(KeyNew == key_right){adjust_item = 0;lcd_write_inst(time_hourh_addr);}}}// -------------------------------------------------------void set_alarm2(void){if (adjust_item == 0) // set hourh{if (((AlarmTime2.hourl <4) & (KeyNew < 3)) | ((AlarmTime2.hourl >3) & (KeyNew <2))){AlarmTime2.hourh = KeyNew;lcd_write_data(AlarmTime2.hourh + '0'); // refresh hourh//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item = 6;lcd_write_inst(time_secondl_addr+3);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_hourl_addr);}}else if (adjust_item == 1) // set hourl{if (((AlarmTime2.hourh == 2) & (KeyNew < 4)) | ((AlarmTime2.hourh < 2) & (KeyNew <=9))){AlarmTime2.hourl = KeyNew;lcd_write_data(AlarmTime2.hourl + '0'); // refresh hourl//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_minuteh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_hourh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_minuteh_addr);}}else if (adjust_item == 2) // set minuteh{if (KeyNew <6){AlarmTime2.minuteh = KeyNew;lcd_write_data(AlarmTime2.minuteh + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_hourl_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_minutel_addr);}}else if (adjust_item == 3) // set minutel{if ((KeyNew >=0) & (KeyNew <=9)){AlarmTime2.minutel = KeyNew;lcd_write_data(AlarmTime2.minutel + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_secondh_addr);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_minuteh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondh_addr);}}else if (adjust_item == 4) // set secondh{if (KeyNew <6){AlarmTime2.secondh = KeyNew;lcd_write_data(AlarmTime2.secondh + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_minutel_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondl_addr);}}else if (adjust_item == 5) // set secondl{if ((KeyNew >=0) & (KeyNew <=9)){AlarmTime2.secondl = KeyNew;lcd_write_data(AlarmTime2.secondl + '0');//lcd_write_inst(0x10); // move cursor backadjust_item ++;lcd_write_inst(time_secondl_addr+3);}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_secondh_addr);}else if(KeyNew == key_right){adjust_item ++;lcd_write_inst(time_secondl_addr+3);}}else if (adjust_item == 6) // set on/off{if ((KeyNew == key_up) | (KeyNew == key_down)){if (Alarm2Enable){Alarm2Enable =false; // disable alarm2lcd_write_data('f');lcd_write_data('f');}else{Alarm2Enable =true; // enable alarm2lcd_write_data('n');lcd_write_data(' ');}//lcd_write_inst(time_secondl_addr+3);adjust_item = 0;lcd_write_inst(time_hourh_addr);Alarm2Cnt = 0;}else if(KeyNew == key_left){adjust_item --;lcd_write_inst(time_secondl_addr);}else if(KeyNew == key_right){adjust_item = 0;lcd_write_inst(time_hourh_addr);}}}// -------------------------------------------------------void main(void){unsigned char cnt;TRISC = 0x03; // PORTC.3 drive led,low activePORTC_MAP = 0x00;led = 0;BackLightEn = 0;BackLightTimer = 0;PORTC = PORTC_MAP;TRISA = 0xff; // low half byte as keyscan inTRISE = 0x00;ADCON0 = 0x00;ADCON1 = 0x06; // all digital I/Oslcd_init();INTCON = 0x00;lcd_write_inst(0x80); // set lcd ddram addressfor (pStr = StrPower1;*pStr!=0;pStr++){lcd_write_data(*pStr);}lcd_write_inst(0x0c); // LCD cursor offPIR1 = PIR2 = 0x00;T1CON = 0x0f; // T1CON: -- T1CKPS1 T1CPS0 T1OSCEN /T1SYNC TMR1CS TMR1ONTMR1H = 0x80;TMR1L = 0x00;。

PIC16F877A超声波测距1602显⽰距离#include#include__CONFIG(0x1832);#define uchar unsigned char#define uint unsigned intconst uchar dis1[]={"The distance is"};uchar dis2[5];#define lcden RA0#define rs RA1unsigned long S;uint time;uchar i=0;uchar S_buffer[4];bit flag =0;void delay(uint x){uint a,b;for(a=x;a>0;a--)for(b=110;b>0;b--);}void write_com(uchar com)//写指令数据到LCD {rs=0;PORTB=com;delay(5);lcden=1;delay(5);lcden=0;}void write_data(uchar data)//写显⽰数据到LCD {rs=1;PORTB=data;delay(5);}void lcd_init(){lcden=1;write_com(0x38); write_com(0x0c); write_com(0x06); write_com(0x01);}void shuju()//数据函数{dis2[0]=S/100+0x30; dis2[1]=S/10%10+0x30; dis2[2]=S%10+0x30; dis2[3]='c';dis2[4]='m';}void interrupt time0(){flag=0;TMR1IF=0;TMR1L=0;TMR1H=0;T1CON=0x20;}void init(){ADCON1=0X07; OPTION=0X8f; TRISA=0;TRISB=0;TRISC=0x04;PORTC=0;PORTD=0X01;PORTE=0X07;RBIE=0;INTCON=0xc0;//PEIE使能和GIE（总中断）使能PIE1=0x01;//使能定时器1 TMR1L=0;TMR1H=0;}void display(){shuju();write_com(0x80+0x48);for(i=0;i<5;i++){write_data(dis2[i]);}}void StartModule(){RC1=1; //启动⼀次模块NOP();NOP();NOP();NOP();NOP();NOP();NOP();NOP();NOP();NOP();NOP();NOP();void Count(void){time=TMR1H*256+TMR1L;TMR1H=0;TMR1L=0;S=(int)(time*1.98)*1.3*3/10; //算出来是CM/*if(((S<4)||(S>=400))||flag==0) //超出测量范围显⽰"999"{S=999;}else{S_buffer[i]=S; //将测量结果的数据放⼊缓冲区i++;if(i==4){S=(S_buffer[0]+S_buffer[1]+S_buffer[2]+S_buffer[3])/4; //得到四个数据取平均i=0;} */// }}void main(){uchar i;init();lcd_init();i=0;write_com(0x80);while(dis1[i]!='\0'){write_data(dis1[i]);i++;}PORTA=0xff;StartModule();flag=1;while((!RC2)&&flag); //当echo为零时等待,中断flag跳出等待T1CON=0x21; //开启计数while(RC2&&flag); //当echo为1计数并等待T1CON=0x20; //关闭计数Count(); //计算display();delay(50);}}。

PIC16F877原理简介1.1 PIC16F877特性：PIC16F877是由Microchip公司所生产开发的新产品，属于PICmicro系列单片微机，具有Flash program程序内存功能，可以重复烧录程序，适合教学、开发新产品等用途；而其内建ICD(In Circuit Debug)功能，可以让使用者直接在单片机电路或产品上，进行如暂停微处理器执行、观看缓存器内容等，让使用者能快速地进行程序除错与开发。

如图1为PIC16F877的40根接脚图，PDIP是指一般最常见的DIP(Dual In Line Package)包装，而PIC单片机也有PLCC(Plastic Leaded Chip Carrier)与QFP(Quad Flat Package)两种形式的包装，依照不同的需求，寻找不同的包装形式。

如图所示，每根接脚都有其特定功能，例如Pin11与Pin32(VDD)为正电源接脚，Pin12与Pin31(VSS)为地线接脚；而有些接脚有两种甚至三种以上功能，例如Pin2(RA0/AN0)代表PORTA的第一支接脚，在系统重置(Reset)后，可自动成为模拟输入接脚，接收模拟讯号，也可经由程序规划为数字输出输入接脚。

图1. PDIP40引脚PIC16F877接脚说明图2. PDIP28和SOIC28引脚PIC16F877接脚图说明图3. PLCC44引脚PIC16F877脚位图说明图4. QFP44引脚PIC16F877引脚图说明PIC16F877属于闪控式(Flash)单片机，可以重复烧录，其ROM的容量总共是8K words，以2K为一个page，区分为4个pages；内部RAM总共有512个字节(00f~1FFh)，以128个字节为一个Bank，共区分为4个Bank，如图5所示，每个Bank的前半段都有其特殊用途，分别连接到其特殊功能模块，例如I/O、CCP、Timer、USART、MSSP等。

用PIC16F877A单片机制作的PWM参数测量仪用PIC16F877A单片机制作的PWM参数测量仪一、测量原理电路如上图（电源电路略）。

外部频率信号从单片机CCP1（RC2）脚输入，测量结果显示在液晶屏上。

PIC16F877A单片机内部有2个CCP模块。

当它工作在PWM方式时。

可以产生周期和电平宽度均可由编程决定的PWM波形；当它工作在捕捉方式时。

可以捕捉外部输入脉冲的上升沿或下降沿，当输入信号发生边沿跳变时，CCP模块立即把当时TMR1的16位计数值放入CCPRxH和CCPRxL寄存器。

并产生相应的中断。

利用CCP 模块的捕捉功能，可以很容易地完成。

PWM信号的周期、频率、脉宽、占空比等参数的测量。

PWM信号参数的测量以周期测频法为基础。

原理如右图所示。

把单片机的CCP1模块设置为捕捉模式，先把CCP1设置为捕捉脉冲的上升沿。

当脉冲信号上升沿到来时。

触发CCP中断，并在中断服务程序中记录下此时TMR1寄存器中16位的值T1：然后把CCP1模块设置成捕捉脉冲下降沿，当脉冲信号下降沿到来时，再次触发CCP中断。

并在中断服务程序中记录下此时TMR1寄存器中16位的值T2；最后把CCP1模块设置成捕捉脉冲上升沿，当脉冲信号上升沿到来时，触发CCP 中断，并在中断服务程序中记录下此时TMR1寄存器中16位的值T3，这样就完成了PWM信号一个周期的测量。

示例程序如下：通过T1~T3可算出PWM信号的周期、频率、脉宽、占空比等。

当PIC16F877A使用4MHz晶振时。

时钟周期=1/4MHz=250ns，指令周期=1μs，TMR1寄存器中16位数值的单位就是μs。

PWM信号各参数的计算方法如下：信号周期：T=（T3-T1）μs；信号频率：F=1000000/T；脉冲宽度：P=（T2-T1）μs；占空比：R=P/T×100％。

为了提高准确性。

可以重复测量多个周期的PWM信号参数，以平均值为最终测量结果。

实验二程序清单：（1）编写程序使8个LED实现双跳灯显示//===========led程序===========#include <pic.h>//===========变量定义==========void delay(int z);//===========主程序============main(){TRISD=0x00;while(1){PORTD=0x03;delay(200);PORTD=0x0c;delay(200);PORTD=0x30;delay(200);PORTD=0xc0;delay(200);}}void delay(int z){int x,y;for(x=z;x>0;x--)for(y=120;y>0;y--);}（2）编写程序实现8个LED灯高四位和低四位交替点亮//===========led程序===========#include <pic.h>//===========变量定义==========void delay(int z);//===========主程序============main(){TRISD=0x00;while(1){PORTD=0xf0;delay(500);PORTD=0x0f;delay(500);}}void delay(int z){int x,y;for(x=z;x>0;x--)for(y=120;y>0;y--);}（3）编写程序使第一次按下按键时单双星闪（1、3、5、7个 LED灯与2、4、6、8个LED交替点亮），第二次按下按钮时高四位的LED和低四位的LED交替点亮，这两种显示方式依次循环#include <pic.h>//===========变量定义==========void delay(int z);void KEYSCAN();#define shuru RB0unsigned int i,j;//===========主程序============ main(){TRISD=0x00;TRISB=0X01;//设置RB0为输入i=0;PORTD=0XFF;while(1){KEYSCAN();if(i%2==1){PORTD=0xaa;delay(500);PORTD=0x55;delay(500);}if(i%2==0){PORTD=0xf0;delay(500);PORTD=0x0f;delay(500);}}}void delay(int z){int x,y;for(x=z;x>0;x--)for(y=120;y>0;y--);}void KEYSCAN(){while(1){if(shuru==1)break;} /*等待有键按下*/delay(10); /*软件延时*/if(shuru==1)i++; /* 如果仍有键按下，则调用键服务子程序*/}实验三程序清单：（1）4*4键盘扫描#include<pic.h> //包含单片机内部资源预定义const charLEDCODE[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x77,0x7c,0x 39,0x5e,0x79,0x71};int result;void delay(); //delay函数申明void init(); //I/O口初始化函数申明void scan(); //按键扫描程序申明void display(int x); //显示函数申明//---------------------------------------------------//主程序void main(){while(1) //循环工作{init(); //调用初始化子程序scan(); //调用按键扫描子程序display(result); //调用结果显示子程序}}//---------------------------------------------------//初始化函数void init(){TRISD=0X0f; //设置C口高4位为输入，低4位为输出TRISC=0X00; //设置D口为输出PORTC=0X00;PORTD=0X00; //先清除所有显示}//按键扫描程序void scan(){PORTD=0XEF; //C3输出低电平，其他三位输出高电平asm("nop"); //插入一定延时，确保电平稳定result=PORTD; //读回C口高4位结果result=result&0x0f; //清除低4位if(result!=0x0f) //判断高4位是否为全1（全1代表没按键按下）？{result=result|0xE0; //否，加上低4位0x07，做为按键扫描的结果return;}PORTD=0XDF; //C3输出低电平，其他三位输出高电平asm("nop"); //插入一定延时，确保电平稳定result=PORTD; //读回C口高4位结果result=result&0x0f; //清除低4位if(result!=0x0f) //判断高4位是否为全1（全1代表没按键按下）？{result=result|0xD0; //否，加上低4位0x07，做为按键扫描的结果return;}PORTD=0XBF; //C3输出低电平，其他三位输出高电平asm("nop"); //插入一定延时，确保电平稳定result=PORTD; //读回C口高4位结果result=result&0x0f; //清除低4位if(result!=0x0f) //判断高4位是否为全1（全1代表没按键按下）？{result=result|0xB0; //否，加上低4位0x07，做为按键扫描的结果return;}PORTD=0X7F; //C3输出低电平，其他三位输出高电平asm("nop"); //插入一定延时，确保电平稳定result=PORTD; //读回C口高4位结果result=result&0x0f; //清除低4位if(result!=0x0f) //判断高4位是否为全1（全1代表没按键按下）？{result=result|0x70; //否，加上低4位0x07，做为按键扫描的结果return;}}//显示程序void display(int x){switch(result){case 0xee:PORTC= LEDCODE[0];delay();break; case 0xed:PORTC= LEDCODE[1];delay();break; case 0xeb:PORTC= LEDCODE[2];delay();break; case 0xe7:PORTC= LEDCODE[3];delay();break;case 0xde:PORTC= LEDCODE[4];delay();break;case 0xdd:PORTC= LEDCODE[5];delay();break; case 0xdb:PORTC= LEDCODE[6];delay();break; case 0xd7:PORTC= LEDCODE[7];delay();break;case 0xBE:PORTC= LEDCODE[8];delay();break;case 0xbd:PORTC= LEDCODE[9];delay();break; case 0xBb:PORTC= LEDCODE[10];delay();break; case 0xb7:PORTC= LEDCODE[11];delay();break; case 0x7E:PORTC= LEDCODE[12];delay();break; case 0x7d:PORTC= LEDCODE[13];delay();break; case 0x7b:PORTC= LEDCODE[14];delay();break;case 0x77:PORTC= LEDCODE[15];delay();break;}}//延时程序void delay() //延时程序{int i; //定义整形变量for(i=0x100;i--;); //延时}（2）数码管显示#include<pic.h> //包含单片机内部资源预定义// __CONFIG(0x1832);//芯片配置字，看门狗关，上电延时开，掉电检测关，低压编程关，加密，4M晶体HS振荡void delay(); //delay函数申明void init(); //I/O口初始化函数申明char TABLE[]={0,1,2,3,4}; //定义常数0-5的数据表格const charLEDCODE1[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F,0x00};//共阴码void main(){init(); //调用初始化函数while(1) //死循环，让数码管持续{PORTC=0X01; //点亮第1位数码管PORTD=~LEDCODE1[TABLE[0]]; //D口输出数据表格第1个数据0 delay();PORTD=0xFF; //延时一定时间，保证数码管亮度PORTC= 0x02;PORTD=~LEDCODE1[TABLE[1]]; //显示数据1delay();PORTD=0xFF;PORTC= 0x04;PORTD=~LEDCODE1[TABLE[2]]; //显示数据2delay();PORTD=0xFF;PORTC= 0x08;PORTD=~LEDCODE1[TABLE[3]]; //显示数据3delay();PORTD=0xFF;}}void init() //I/O口初始化函数{TRISC=0X00; //设置A0输出，其他输入TRISD=0X00; //设置D口输出PORTC=0x00;PORTD=0x00; //先熄灭所有显示}void delay() //延时程序{int i; //定义整形变量for(i=0xF000;i--;); //延时 //0x400for(i=0xff;i--;);}void display(){int i ;unsigned char DISPBIT;DISPBIT=0x01;for (i=0;i<=3;i++){PORTC=DISPBIT; //点亮第1位数码管PORTD=~LEDCODE1[TABLE[i]]; //D口输出数据表格第1个数据0 delay();PORTD=0xFF;DISPBIT=DISPBIT<<1;}}实验四程序清单：（1）方波发生器＃include<pic.h>sbit P1_0=P1^0;void timer0(void){P1_0=!P1_0;TH0=-(1000/256); /*计数初值重装*/TL0=-(1000%256);}void main(void){TMOD=0x01; /*T0工作在定时器方式1*/P1_0=0;TH0=-(1000/256); /*预置计数初值*/TL0=-(1000%256);EA=1; /*CPU开中断*/ET0=1; /*T0开中断*/TR0=1; /*启动T0*/do{}while(1);}（2）程序说明：P1口输出,低电平有效#include<pic.h>#define uchar unsigned char //定义无符号字符#define uint unsigned int //定义无符号整数void Delayms(uint x){ //定义延时函数uint i,j;for(i=x;i>0;i--)for(j=110;j>0;j--);}void main(){uint i;uchar temp;while(1){temp=0x01; //8个流水灯逐个闪动for(i=0;i<8;i++){P1=~temp;Delayms(300);temp<<=1;}temp=0x80; //8个流水灯反向逐个闪动for(i=0;i<8;i++){P1=~temp;Delayms(300);temp>>=1;}temp=0xfe; //8个流水灯依次全部点亮for(i=0;i<8;i++){P1=temp;Delayms(300);temp<<=1;}temp=0x7f; //8个流水灯依次反向全部点亮for(i=0;i<8;i++){P1=temp;Delayms(300);temp>>=1;}}}实验六程序清单：（1） U1发送部分程序清单#include<pic.h>unsigned tran[10]={0,2,4,6,8,1,3,5,7,9};unsigned char k,x;int i=0;const chartable[20]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xD8,0x80,0x90,0x88,0x83,0x c6,0xa1,0x86,0x8c,0x7f,0xbf,0x89,0xff};void sciint(){SPBRG=0x19;TXSTA=0x04;RCSTA=0x80;TRISC6=1;TRISC7=1;TRISB=0x00;}void delay(){for(i=0x1FFF;i>0;i--) {;}}void display(){for(k=0;k<10;k++) { x=tran[k];PORTB=table[x];delay();}}main(){sciint();di();TXEN=1;CREN=1;for(k=0;k<10;k++){ TXREG=k;while(1){if(TXIF==1)break;}while(1){if(RCIF==1)break;}RCREG=RCREG;}display();while(1){;}}（2） U2接收部分程序清单#include<pic.h>unsigned rece[10];unsigned char k,x;int i=0;const chartable[20]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xD8,0x80,0x90,0x88,0x83,0x c6,0xa1,0x86,0x8c,0x7f,0xbf,0x89,0xff};void sciint(){SPBRG=0x19;TXSTA=0x04;RCSTA=0x80;TRISC6=1;TRISC7=1;TRISB=0x00;}void delay(){for(i=0x1FFF;i>0;i--){;}}void display(){for(k=0;k<10;k++) { x=rece[k];PORTB=table[x]; delay();}}main(){sciint();di();CREN=1;TXEN=1;for(k=0;k<10;k++){ while(1){if(RCIF==1)break;}rece[k]=RCREG; TXREG=rece[k];while(1){if(TXIF==1)break;}}display();while(1){;}}实验七程序清单：（1）单路显示#include<pic.h>unsigned int i;unsigned int a,b,c;static inttable[20]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xD8,0x80,0x90,0x88,0x83,0x c6,0xa1,0x86,0x8c,0x7f,0xbf,0x89,0xff};void initial() //初始化{TRISB=0x00; //定义为输出PORTB=0x13; //数码管全灭TRISC=0x00;PORTC=0x13;a=0;b=0;c=0;}void ADC() //A/D转换初始化{ADCON0=0x41; //0100 0001 选择转换时钟8Tosc，选择A/D通道为RA0，//打开A/D转换器。

课程设计课程名称_微机原理与单片机技术实践学生学院_____自动化学院________ 专业班级_电子信息科学与技术学号___ ____学生姓名_____ _ _______指导教师2012年4 月25 日摘要本次实训使用PIC16F877A单片机设计最小系统并扩展,进一步了解PIC16系列单片机的功能与应用。

在扩展功能上应用PIC16F877A单片机来控制小车的行驶方向，通过单片机接收到不同的信息，编写正确的程序，来控制小车不同的行驶方向。

关键词：PIC16F877A单片机， Mplab，C语言，目录1 设计任务目的及要求 (4)2 实验原理 (4)2.1PIC16F877A单片机简介 (4)3设计方案.......................................................................... 错误！未定义书签。

4 实验结果 (8)5 心得体会 (8)参考文献 (8)1 设计任务目的及要求使用PIC16F877A单片机设计一个最小系统，在单片机小系统上开发应用系统，对其进行功能扩展，编写相应的程序，使设计功能得到实现。

2 实验原理2.1PIC16F877A单片机简介PIC系列单片机是美国Microchip公司生产的产品，具有性能完善，功能强大，学习容易，开发应用方便等突出优点。

PIC系列单片机采用哈佛总线结构，彻底将芯片内部的数据总线和指令总线分开，大大提高了CPU的执行指令速度和工作效率。

采用精简指令RISC技术，优先选取使用频率最高的简单指令，避免复杂指令，采用控制逻辑为主的设计理念。

采用更为简单的寻址方式，功耗低，驱动能力强，这也是PIC系列单片机的一大特点。

实验采用的单片机封装方式是如下图：3设计方案：本次实训应用PIC16F877A单片机来控制小车的行驶方向，使用RB口的RB4~RB7口做为输入端，直接使用最小系统上的4个按钮来作为输入信号，RD0~RD3作为输出端，来做为驱动的控制电流。