基于51单片机的电子琴设计.zip

#include <reg51.h> #include <intrins.h> #define uint unsigned int #define uchar unsigned char #define output P1 #define input P1 //方便移植在其他电路板上，我的电路使用P1口做键盘输入接口 //定义16个按键 enum KEY{key0,key1,key2,key3,key4,key5,key6,key7,key8,key9,key10,key11,key12,key13,key14,key15}; uchar code table[]={ //数组定义,显示数码管 0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07, 0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x00}; unsigned int code Freqtab[] = { //定时半周期的初始值 64021,64103,64260,64400, //低音3 4 5 6 64524,64580,64684,64777, //低音7,中音1 2 3 64820,64898,64968,65030, //中音4 5 6 7 65058,65110,65157,65178}; //高音1 2 3 4 uint FreqTemp; //蜂鸣器声音不怎么样，我们使用扬声器，接P3.7口 sbit SPEAK = P3^7; void delay1ms(uint n) //误差 0us ,延时n毫秒 { uint a,b,c; for(c=n;c>0;c--) for(b=199;b>0;b--) for(a=1;a>0;a--); } uint key_input(void) { uchar temp1,temp2; //临时保存读取的行或者列 uchar num = 16; //返回按键的值 output = 0x0f; temp1 = input; //先读取行 if(0x0f != temp1) //按键按下 { delay1ms(5); //延时，消除抖动 temp1 = input; //再次读取行 if(0x0f != temp1) //说明按键确实按下 { temp1 = temp1 & 0x0f; //保留低4位 output = 0xf0; //准备读取列 delay1ms(1); //延时一下，防止下一句读不到 temp2 = input; //直接读取列 temp2 = temp2 & 0xf0; //保留高4位 temp1 = temp1 | temp2; //将temp1和temp2的值合并 } } switch(temp1) { case 0xee:num=0;break; case 0xde:num=1;break; case 0xbe:num=2;break; case 0x7e:num=3;break; case 0xed:num=4;break; case 0xdd:num=5;break; case 0xbd:num=6;break; case 0x7d:num=7;break; case 0xeb:num=8;break; case 0xdb:num=9;break; case 0xbb:num=10;break; case 0x7b:num=11;break; case 0xe7:num=12;break; case 0xd7:num=13;break; case 0xb7:num=14;break; case 0x77:num=15;break; default:break; } return num; } void T0_INT(void) interrupt 1 { TL0 = FreqTemp; //载入定时半周期的初始值 TH0 = FreqTemp >> 8; SPEAK = ~SPEAK; //发音 } int main() { TMOD = 0X01; //定时器T0设置为方式1 EA = 1; ET0 = 1; TR0 = 0; while(1) { uint num,temp; num = key_input(); temp = num; P0 = table[num]; if(16 != num) { FreqTemp = Freqtab[num]; TR0 = 1; while(0xf0 != output); //检测按键松开 TR0 = 0; SPEAK = 1; } } return 0; }