#include <reg51.h>#include <intrins.h>#include <stdio.h>#include <stdlib.h>unsigned char code Error[]={"error"};unsigned char code Systemerror[]={"system error"};unsigned char code Lcd[]={"lcd calculate"};char str[16];sbit RS=P2^0;sbit RW=P2^1;sbit E=P2^2;sbit BF=P0^7;/***********************函数功能：延时1ms***********************/void delay1ms(){unsigned char i,j;for (i=0;i<10;i++)for (j=0;j<33;j++);}/************************函数功能：延时n毫秒入口参数：n************************/void delaynms(unsigned char n){unsigned char i;for (i=0;i<n;i++)delay1ms();}/************************************函数功能：判断液晶模块的忙碌状态返回值：result。

result=1，忙碌；result=0，不忙。

************************************/bit BusyTest(void){bit result;RS=0; //根据规定，RS为低电平、RW为高电平时，可以读状态RW=1;E=1; //E=1，才允许读/写_nop_();_nop_();_nop_();_nop_();result=BF; //将忙碌标志电平赋给resultE=0;return result;}/*************************************函数功能：将模式设置指令或显示地址写入液晶模块入口参数:dictate**************************************/void WriteInstruction(unsigned char dictate){while(BusyTest()==1); //如果忙就等待RS=0; //根据规定，RS和R/W同为低电平时，可以写入指令RW=0;E=0;_nop_();_nop_();P0=dictate; //将数据送入P0口，即写入指令或地址_nop_();_nop_();_nop_();_nop_();E=1; //E置高电平_nop_();_nop_();_nop_();_nop_();E=0;}/*****************************************函数功能：指定字符显示的实际地址入口参数:x,y*****************************************/void WriteAddress(unsigned char x,unsigned char y){unsigned char temp;if(x==0){switch(y){case 0:temp=0x00; break;case 1:temp=0x01; break;case 2:temp=0x02;break;case 3:temp=0x03;break;case 4:temp=0x04;break;case 5:temp=0x05;break;case 6:temp=0x06;break;case 7:temp=0x07;break;case 8:temp=0x08;break;case 9:temp=0x09;break;case 10:temp=0x0a;break;case 11:temp=0x0b;break;case 12:temp=0x0c;break;case 13:temp=0x0d;break;case 14:temp=0x0e;break;case 15:temp=0x0f;break;}}if(x==1){switch(y){case 0:temp=0x40;break;case 1:temp=0x41;break;case 2:temp=0x42;break;case 3:temp=0x43;break;case 4:temp=0x44;break;case 5:temp=0x45;break;case 6:temp=0x46;break;case 7:temp=0x47;break;case 8:temp=0x48;break;case 9:temp=0x49;break;case 10:temp=0x4a;break;case 11:temp=0x4b;break;case 12:temp=0x4c;break;case 13:temp=0x4d;break;case 14:temp=0x4e;break;case 15:temp=0x4f;break;}}WriteInstruction(temp|0x80); //显示位置的确定方法规定为“80H+地址码x”}/*****************************************函数功能：将数据（字符的标准ASCII码）写入液晶模块入口参数：y*****************************************/void WriteData (unsigned char y){while(BusyTest()==1);RS=1; //RS为高电平，RW为低电平时，可以写入数据RW=0;E=0;P0=y; //将数据送入P0口，即将数据写入液晶模块_nop_();_nop_();_nop_();_nop_();E=1;_nop_();_nop_();_nop_();_nop_();E=0; //当E由高电平跳变成低电平时，液晶模块开始执行指令}/*****************************************函数功能：对LCD的显示模式进行初始化设置*****************************************/void LcdInitiate(void){delaynms(15); //延时15ms，首次写指令时应给LCD一段较长的反应时间WriteInstruction(0x38); //显示模式设置delaynms(5);WriteInstruction(0x38);delaynms(5);WriteInstruction(0x38);delaynms(5);WriteInstruction(0x0c); //显示模式设置：显示开，无光标，光标不闪烁delaynms(5);WriteInstruction(0x06); //显示模式设置：光标右移，字符不移delaynms(5);WriteInstruction(0x01); //清屏幕指令，将以前的显示内容清除delaynms(5);}/***************************************函数功能：显示字符串***************************************/void display_error(){unsigned char i;WriteAddress(0,0);i=0;while(Error[i]!='\0'){WriteData(Error[i]);i++;delaynms(100);}}void display_systemerror(){unsigned char i;WriteAddress(0,0);i=0;while(Systemerror[i]!='\0'){WriteData(Systemerror[i]);i++;delaynms(100);}}void display_lcd(){unsigned char i;WriteAddress(0,0);i=0;while(Lcd[i]!='\0'){WriteData(Lcd[i]);i++;delaynms(100);}}/*************************** 函数功能：按键判断**************************/bit judge(){unsigned char keycode;P1=0x0f;keycode=P1;if(keycode==0x0f)return(0);elsereturn(1);}/*****************************函数功能：键盘扫描*****************************/ unsigned char scan(){unsigned char keycode,keyscan;keyscan=0xef;while(keyscan!=0xff){P1=keyscan;keycode=P1;if((keycode&0x0f)!=0x0f)break;keyscan=(keycode<<1)|0x0f;}keycode=~keycode;return(keycode);}/*******************************函数功能：扫描键盘返回值******************************/ unsigned char Key_Num(){unsigned char keycode;unsigned char yong;if(judge()){delaynms(20);if(judge()){keycode=scan();while(judge());switch(keycode){case 0x11:yong='7';break;case 0x12:yong='4';break;case 0x14:yong='1';break;case 0x18:yong=0;break;case 0x21:yong='8';break;case 0x22:yong='5';break;case 0x24:yong='2';break;case 0x28:yong='0';break;case 0x41:yong='9';break;case 0x42:yong='6';break;case 0x44:yong='3';break;case 0x48:yong='=';break;case 0x81:yong='/';break;case 0x82:yong='*';break;case 0x84:yong='-';break;case 0x88:yong='+';break;default:display_systemerror() ;}return(yong);}}elsereturn(0xff);}/************************************** itoa函数定义*********************************/ unsigned char itoa(long int num){unsigned char i,j,L;unsigned char temp[16];for(i=0;num!=0;i++){temp[i]=num%10+48;num=num/10;}L=i;if(i>16){display_systemerror();}for(j=0;j<=L;j++){str[j]=temp[i];i--;}return(L);}/*****************************************函数功能：主函数****************************************/void main(){long int a;long int b;unsigned char flag;unsigned char sign;unsigned char i,j,s,x;unsigned char num;unsigned char fgh;unsigned char temp[16];LcdInitiate();display_lcd();delaynms(20);WriteInstruction(0x01);flag=1;while(1){num=Key_Num();if(num!=0xff){if(fgh==1){WriteInstruction(0x01);fgh=0;}if((num!='+')&&(num!='-')&&(num!='*')&&(num!='/')&&(num!='.')&&(num!='=')){if(flag==1){a=a*10+num-48;}else{b=num-48+b*10;}}if(num==0){i=0;flag=1;a=0;b=0;WriteInstruction(0x01);}if((num=='+')||(num=='-')||(num=='*')||(num=='/')){flag=0;switch(sign){case '+':a=a+b;break;case '-':a=a-b;break;case '*':a=a*b;break;case '/': {if(b!=0){ a=a/b;break; }else{WriteInstruction(0x01);flag=1;WriteAddress(0,1);display_error();delaynms(40);WriteInstruction(0x01);break;}}default:break;}sign=num;b=0;}if(num=='='){flag=1;switch(sign){case '+':a=a+b;break;case '-':a=a-b;break;case '*':a=a*b;break;case '/':a=a/b;break;default:break;}temp[i]=num;WriteAddress(0,i);WriteData(num);for(s=0;s<16;s++)temp[s]=0;s=0;//WriteAddress(1,8);//WriteData(a+48);x=itoa(a); //函数转换WriteAddress(1,1);while(s<=x){WriteData(str[s]);s++;delaynms(100);}sign=0;a=b=0;j=0;for(s=0;s<16;s++)str[s]=0;s=0;fgh=1;i=0;}if(i<16){if(num!='='){if((i==1)&& (temp[0]=='0') )//如果第一个字符是0，判读第二个字符{temp[0]=num; //如果是1-9数字，说明0没有用，则直接替换第一位0WriteAddress(0,0);//输出数据WriteData(num);}else{temp[i]=num;WriteAddress(0,i);//输出数据WriteData(num);i++; //输入数值累加}}}else{i=0;WriteInstruction(0x01);}}}}枯藤老树昏鸦，小桥流水人家，古道西风瘦马。