基于 51 单片机的按键切换播放音乐原理图：Q4Q3Q2Q1Q0Q0Q4Q3Q2Q1XTAL218XTAL119ALE30EA31PSEN29RST9P0.0/AD039P0.1/AD138P0.2/AD237P0.3/AD336P0.4/AD435P0.5/AD534P0.6/AD633P0.7/AD732P1.0/T21P1.1/T2EX2P1.23P1.34P1.45P1.56P1.67P1.78P3.0/RXD10P3.1/TXD11P3.2/INT012P3.3/INT113P3.4/T014P3.7/RD17P3.6/WR16P3.5/T115P2.7/A1528P2.0/A821P2.1/A922P2.2/A1023P2.3/A1124P2.4/A1225P2.5/A1326P2.6/A1427U1AT89C52LS1SPEAKERQ1NPNR12k4234567891RP1RESPACK-8R210kD11N4007D21N4007D31N4007D41N4007D51N4007引脚说明：共 5 个按键,分别接 51 单片机的 P0～P4 引脚，前 4 个按键控制播放设置好的四首音乐，第 5个按键用来关闭音乐。按键采纳中断方式，任意时刻按下任意按键则立即进入所按按键的功能;蜂鸣器接单片机的 P3。6 口。仿真说明：使用 proteus 仿真,晶振：12MHZ。程序代码如下：/＊12Mhz 晶振工作＊/#include 〈reg52.h>#define uint unsigned int#define uchar unsigned charsbit voice=P3^6;uchar code sound1[］={0xff，0x40,0x80,0x30,0x40，0x2b,0x40，0x26，0x80，0x24,0x10，0x26，0x40,0x30,0x40,0x2b,0x80，0x30,0x40，0x39,0x40,0x30,0xc0,0x40,0x80,0x30,0x40,0x2b，0x40，0x26，0x40,0x26,0x20，0x24,0x20，0x20,0x40,0x30,0x40,0x24，0x80,0x26，0x10,0x20，0x40,0x2b,0x20,0x26,0x20，0x26，0x20,0x2b,0x20,0x2b，0xc0，0x26，0x80,0x20,0x40，0x19，0x40,0x19，0x80,0x1c,0x10，0x1c，0x80,0x20，0x40,0x20，0x20，0x1c，0x20，0x19，0x40，0x1c，0x20,0x20,0x20，0x26,0xc0,0x24，0x80，0x24，0x10,0x20,0x40,0x1c，0x40，0x20,0x40，0x24,0x20,0x26，0x20，0x2b，0x80，0x33，0x40，0x33，0x20,0x39，0x20,0x40，0x40,0x39，0x40，0x30,0xc0,0x18，0x80,0x1c，0x80，0x24，0x80,0x20，0x10,0x1c，0x80,0x19,0x40，0x19，0x20，0x19,0x20，0x19，0x40，0x1c，0x20，0x20,0x20，0x26，0xc0，0x18，0x80,0x1c，0x80,0x24,0x80,0x20,0x10，0x1c，0x80，0x1c，0x40,0x1c,0x20,0x1c，0x20,0x1c,0x40，0x24，0x20，0x26,0x20，0xff，0x20，0x00}；//同一首歌*/uchar code sound2［］={0xff，0x18，0x40,0x1c,0x20，0x18，0x20，0x13，0x40,0x13，0x20，0x15,0x20，0x13，0x20，0x15,0x20，0x13，0x20，0x15，0x20，0x18,0x20,0x19，0x20，0x1c，0x20，0x20,0x20,0x1c,0x40,0x19,0x20，0x18，0x20,0...
