buzzer.c

#include <reg52.h>
#include <string.h>
#include "utilities.h"
#include "music.h"
#define RldTmr(fr) 65536 - (11059200 / 12) / ((fr) << 1)
#define FuDian(n) ((n) << 1) / 3    //附点n分音符的换算

sbit BUZZ = P1^6;

uint code noteFreq[] = {    //中音 1-7 和高音 1-7对应的频率列表 低音
    523, 587, 659, 698, 784, 880, 988,
    1047, 1175, 1319, 1397, 1568, 1760, 1976,
    //261, 293, 329, 349, 392, 440, 494
};
uint code tmrRld[] = {      //中音 1-7 和高音 1-7对应的定时器重载值
    RldTmr(523), RldTmr(587), RldTmr(659), RldTmr(698), RldTmr(784), RldTmr(880), RldTmr(988),
    RldTmr(1047), RldTmr(1175), RldTmr(1319), RldTmr(1397), RldTmr(1568), RldTmr(1760), RldTmr(1976),
    //RldTmr(261), RldTmr(293), RldTmr(329), RldTmr(349), RldTmr(392), RldTmr(440), RldTmr(494)
};
uchar musicLen[10];
uchar musicNum = sizeof(musicSet) / sizeof(Music);
bit enable = 1, tmrFlg = 0;
uchar musicIdx = 0;
uchar musicSpeed = 72;
uchar nowMusic = 0;

void initMusicInfo() {
    uchar i;
    for (i = 0; i < musicNum; i++) {
        musicLen[i] = strlen(musicSet[i].pNote);
    }
}

void delay(uint n) {
    while (n--) {
        keyDriver();
    }
}
//固定标准为4分音符的速度：例如speed = 108 表示一分钟扫过108个4分音符
void playMusic(uchar musicIdx, uchar speed) {
    uchar i;
    uchar idx;
    uint cnt = 0;
    uint durationCnt = 0;   //当前音符的时值对应的定时器计数
    uint soundCnt = 0;      //当前音符的发声时值对应的计数值
    char * musicNote = musicSet[musicIdx].pNote;
    char * noteDuration = musicSet[musicIdx].pDur;
    for (i = 0; i < musicLen[musicIdx]; ) {
        while (!tmrFlg) ;
        tmrFlg = 0;
        //keyDriver(); //递归实现音乐的嵌套
        if (cnt == 0) {
            idx = musicNote[i] - 1;
            T0RH = tmrRld[idx] >> 8;
            T0RL = tmrRld[idx];
            durationCnt = (ulong)240 * (ulong)noteFreq[idx] / ((ulong)noteDuration[i] * (ulong)speed);
            soundCnt = durationCnt - (durationCnt >> 2);  //当前音符时值的前3/4发声，后1/4静音
            enable = 1;
            cnt++;
        }
        else {
            if (cnt == durationCnt) {
                cnt = 0;
                i++;
            }
            else {
                cnt++;
                if (cnt == soundCnt) {
                    enable = 0;
                }
            }
        }
    }
}