51单片机实现简易电子琴，发出7个音，音调可调

#include <reg52.h> // 51单片机头文件 #define uint unsigned int sbit BUZZER = P2^0; // 将P2.0定义为BUZZER sbit KEY0 = P1^0; sbit KEY1 = P1^1; sbit KEY2 = P1^2; sbit KEY3 = P1^3; sbit KEY4 = P1^4; sbit KEY5 = P1^5; sbit KEY6 = P1^6; sbit KEY7 = P1^7; uint FREQSELECT; // 音阶频率数组 unsigned int FREQ[] = { 63628, 63835, 64021, 64103, 64260, 64400, 64524, 64580, 64684, 64777, 64820, 64898, 64968, 65030, 65058, 65110, 65157, 65178, 65217, 65252, 65283 }; void Delay1ms(uint xms); void main() { uint num = 0; TMOD |= 0x01; IE = 0X82; TR0 = 0; while(1) { if(KEY7 == 0) { num = num+7; if(num >20) { num = 0; } } if(KEY0 == 0) { FREQSELECT = num; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } if(KEY1 == 0) { FREQSELECT = num + 1; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } if(KEY2 == 0) { FREQSELECT = num + 2; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } if(KEY3 == 0) { FREQSELECT = num + 3; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } if(KEY4 == 0) { FREQSELECT = num + 4; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } if(KEY5 == 0) { FREQSELECT = num + 5; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } if(KEY6 == 0) { FREQSELECT = num + 6; TR0=1; Delay1ms(500); TR0=0; Delay1ms(5); } } } void timer0_isr() interrupt 1 { TH0 = FREQ[FREQSELECT]/256; TL0 = FREQ[FREQSELECT]%256; BUZZER = ~BUZZER; } void Delay1ms(uint xms) //@12.000MHz { while(xms) { unsigned char i, j; i = 2; j = 239; do { while (--j); } while (--i); xms--; } }