4x4键盘边播放音乐边开关12v电磁锁

吃灰很久的4x4键盘，终于有了用途了。就从标题所示的功能开始吧。先看下视频。

按A键4下开锁并播放音乐，B键4下关锁，并播另一个曲子

项目用的硬件有：

Arduino uno

4x4键盘

mp3模块

12v电磁锁

5v继电器

4x4键盘内部构造

连线图
[mw_shl_code=applescript,true]//you may copy or modify the code below,but please refer gada888 as the original source
#include <Keypad.h>
char myNum[4];
int i;
unsigned char order[4] = {0xAA,0x06,0x00,0xB0};
#define RELAY 10

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'*','0','#','D'}
};
byte rowPins[ROWS] = {9,8,7,6};
byte colPins[COLS] = {5,4,3,2};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins,
ROWS, COLS);
void setup() {
Serial.begin(9600);
volume(0x1E);
pinMode(RELAY, OUTPUT);
digitalWrite(RELAY, HIGH);
}
void loop() {
    Serial.println("Enter a num -");
  for ( i = 0; i < 4; ++i)
  {
    while((myNum = keypad.getKey())==NO_KEY) {
      delay(1); // Just wait for a key
    }
    while(keypad.getKey() != NO_KEY) {
      delay(1);
    }
  Serial.print(myNum);
  }
  if(myNum[3]=='A')
  {
   play(0x01);
   //delay(500);
   digitalWrite(RELAY, HIGH);
   }
  if(myNum[3]=='B')
  {
    play(0x02);
    //delay(500);
    digitalWrite(RELAY, LOW);
    i=0;
  }
  if(myNum[3]=='*')
  {
    play(0x03);
    delay(500);
    i=0;
  }
  if(myNum[3]=='#')
  {
    play(0x04);
    delay(500);
    i=0;
  }
  if(myNum[3]=='D')
  {
    play(0x05);
    delay(500);
    i=0;
  }
}

void play(unsigned char Track)
{
unsigned char play[6] = {0xAA,0x07,0x02,0x00,Track,Track+0xB3};//0xB3=0xAA+0x07+0x02+0x00,閸楄櫕娓堕崥搴濈娴ｅ秳璐熼弽锟犵崣閸?
Serial.write(play,6);
}
void volume( unsigned char vol)
{
unsigned char volume[5] = {0xAA,0x13,0x01,vol,vol+0xBE};//0xBE=0xAA+0x13+0x01,閸楄櫕娓堕崥搴濈娴ｅ秳璐熼弽锟犵崣閸?
Serial.write(volume,5);
}
[/mw_shl_code]

8错的帖子

为啥要按4下捏