yuzhunyu 发表于 2016-12-2 09:44:42

使用PWM生成基本的钢琴音符

本帖最后由 yuzhunyu 于 2016-12-2 11:32 编辑

所需硬件：1.arduino uno   *1
               2.蜂鸣器            *1
               3.4*4矩阵键盘   *1
电路图：
蜂鸣器接在11号口，矩阵键盘占用2-9号口（r0、r1、r2、r3、c0、c1、c2、c3）


代码：
#define c3 9
#define c2 8
#define c1 7
#define c0 6
#define r3 5
#define r2 4
#define r1 3
#define r0 2
void setup() {
Serial.begin(9600);
pinMode(c0, INPUT_PULLUP);
pinMode(c1, INPUT_PULLUP);
pinMode(c2, INPUT_PULLUP);
pinMode(c3, INPUT_PULLUP);
pinMode(r0, OUTPUT);
pinMode(r1, OUTPUT);
pinMode(r2, OUTPUT);
pinMode(r3, OUTPUT);
pinMode(11, OUTPUT);
}
void loop() {
digitalWrite(r0, LOW);
digitalWrite(r1, HIGH);
digitalWrite(r2, HIGH);
digitalWrite(r3, HIGH);
if (digitalRead(c0) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 119;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c1) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 106;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c2) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 94;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c3) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 89;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
digitalWrite(r0, HIGH);
digitalWrite(r1, LOW);
digitalWrite(r2, HIGH);
digitalWrite(r3, HIGH);
if (digitalRead(c0) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 79;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c1) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 71;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c2) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 63;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c3) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 59;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
digitalWrite(r0, HIGH);
digitalWrite(r1, HIGH);
digitalWrite(r2, LOW);
digitalWrite(r3, HIGH);
if (digitalRead(c0) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 25;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c1) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 20;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c2) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 10;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c3) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 50;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
digitalWrite(r0, HIGH);
digitalWrite(r1, HIGH);
digitalWrite(r2, HIGH);
digitalWrite(r3, LOW);
if (digitalRead(c0) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 50;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c1) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 50;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c2) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 50;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
else if (digitalRead(c3) == LOW) {
    TCCR2A = B01000011;
    TCCR2B = B00001110;
    OCR2A = 50;
    delay(100);
    TCCR2B = B00001000;
    TCCR2A = B00000000;
    digitalWrite(11, LOW);
}
}
原理：
钢琴的基本音符的频率如下
c - 261 HZ
d - 294 HZ
e - 329 HZ
f - 349 HZ
g - 392 HZ
a - 440 HZ
b - 493 HZ
C - 523 HZ
涉及到的公式：
frequency in Hz = 16MHz/prescalar/(OCRA+1)/2 (for register A i.e. pin 11)
比如：生成261hz
TCCR2A = B01000011; (com2a1 com2a0计数器值达到119)
TCCR2B = B00001110; （ca22 ca21 cs20 prescalar选择256)
OCR2A = 119;
代入公式得:16MHZ/256/120/2 = 260.42HZ

上传至UNO，现在你可以试试自己弹一曲“生日快乐”了:lol



hnyzcj 发表于 2016-12-2 13:31:10

不错不错，

yuzhunyu 发表于 2016-12-2 13:40:11

hnyzcj 发表于 2016-12-2 13:31
不错不错，

哈哈:handshake:victory:{:5_179:}

吹口琴的钢铁侠 发表于 2016-12-3 15:45:29

我记得有一个专门的音符的函数库，跟这个有点类似

yuzhunyu 发表于 2016-12-5 09:40:24

吹口琴的钢铁侠 发表于 2016-12-3 15:45
我记得有一个专门的音符的函数库，跟这个有点类似

:handshake

dsweiliang 发表于 2016-12-8 16:41:55

感谢分享爱啊

yuzhunyu 发表于 2016-12-8 18:53:24

dsweiliang 发表于 2016-12-8 16:41
感谢分享爱啊

{:5_198:}{:5_198:}{:5_198:}

zsh888888 发表于 2017-1-2 23:53:39

感谢分享

kimi423520 发表于 2018-6-11 17:00:36

不错， 赞
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