查看“Buzzer Alarm”的源代码

{{Language| Buzzer Alarm}}
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==Objective==

This tutorial will show you how to use Microduino-buzzer with three examples. 
[[File:MicroduinoBuzzer.jpg|600px|center]]

==Equipment==
*'''[[Microduino-CoreUSB]]'''
*'''[[Microduino-BUZZER]]'''
*'''[[Microduino-Sensorhub]]'''
*Other hardware equipment
**USB cable  One
[[File:MicroduinoBuzzer-Equipment.jpg|600px|center]]

==Description==
Generally, buzzer can be divided into active buzzer and passive buzzer. 
*Active buzzer
**Internal oscillating and driving circuit. With voltage signal(high level), the buzzer can make sound.
***Advantage: Easy to use。
***Disadvantage: only one single tone left since fixed frequency. 
*Passive buzzer 
**Since there is no internal oscillating source, the buzzer can't make sound with DC signal. It has to be driven by changing power signal.
***Advantage: With controllable sound frequency, you can achieve the effect of seven musical notes. 
***Disadvantage: A little hard to control. 

==Example 1: Let the buzzer goes off==
===Build module circuit===
*Setup 1：Connect sensor to interface(6) on Hub module with connecting line. 
[[File:MicroduinoBuzzer-D6.jpg|600px|center]]
*Setup 2：Stack Hub and CoreUSB together.
[[File:MicroduinoBuzzer-hub-coreusb.jpg|600px|center]]

===Debugging===
*Setup 1：Use usb cable to connect CoreUSB and PC/Mac and then open Arduino IDE. 
[[File:CoreUSB_Ble_pc.jpg|600px|center]]
* Setup 2：Download the code and copy it to IDE. 
<source lang="cpp">
#define buzzer_pin 6 //Define buzzer pin
#define buzzer_fre 600 //Define output frequency

void setup()
{
  pinMode(buzzer_pin,OUTPUT);
}
 
void loop()
{
    tone(buzzer_pin,buzzer_fre);    //Drive the buzzer 
}
</source>
Select Microduino-CoreUSB as the board card as well as corresponding port(COMXX). Click the right arrow（—>）and download program. When you see upload finish notice, it means the program has been written into CoreUSB.  Then, you'll hear buzzer goes off.  
*“tone(pin,fre)”Function 
**Fixed pin (pin) and output frequency (fre) signal. 
**You can change the value of buzzer_fre and watch buzzer change. 
==Example 2: Buzzer makes alarm==
*Copy program code to IDE and download it to Core board. 
<source lang="cpp">
#define buzzer_pin 6 //Define buzzer pin 

void setup()
{
  pinMode(buzzer_pin,OUTPUT);
}
 
void loop()
{
  for(int i=200;i<=800;i++)  //Increase frequency from 200HZ to 800HZ in a circular manner.
  {
    tone(buzzer_pin,i);    //Output frequency in Number four port. 
    delay(5);      //The frequency lasts 5ms. 
  }
  delay(2000);     //The highest frequency lasts 2s.
  for(int i=800;i>=200;i--)
  {
    tone(buzzer_pin,i);
    delay(10); //The frequency lasts 10ms. 
  }
}
</source>
“for(int i=200;i<=800;i++)”Description: The value of 'i' is 200 initially, which increases 1 each time the 'for' function executes and it will exit from 'for' loop until the value reaches 800. Users can change parameters and watch buzzer change. 

<br>The example adopts 'for' loop to change frequency and therefore make alarm. 

==Example 3: Play music==

*Program code 
<source lang="cpp">
#define buzzer_pin 6 //Define buzzer pin 
int song[] = {
  262, 262, 294, 262, 349, 330,
  262, 262, 294, 262, 392, 349,
  262, 262, 523, 440, 349, 330, 294,
  494, 494, 440, 349, 392, 349
};

int noteDurations[] = {
  4, 4, 2, 2, 2, 1,
  4, 4, 2, 2, 2, 1,
  4, 4, 2, 2, 2, 2, 2,
  4, 4, 2, 2, 2, 1
};

void setup() {
  pinMode(buzzer_pin, OUTPUT);
}

void loop() {
  song_play();
}

void song_play()
{
  for (int thisNote = 0; thisNote < 25; thisNote++)
  {
    int noteDuration = 1000 / noteDurations[thisNote];
    tone(buzzer_pin, song[thisNote], noteDuration);
    int pauseBetweenNotes = noteDuration * 1.20;
    delay(pauseBetweenNotes);
    noTone(buzzer_pin);
  }
}</source>
' song_play()' is music play function and the note (frequency) is saved in ' song[]'. ' noteDurations[]' represents rhythm. 
<br>Music is controlled by tone() and change this function means changing music rhythm. Two types of code: tone(pin, frequency, duration) or tone(pin, frequency)
<br> Seen from the first function, 'pin' represents the pin connecting the speaker and 'frequency' represents sound frequency and 'duration' means time duration (The unit is 'ms'). 
<br> If using the second function, you need another noTone() function to contro noTone(pin) and stop music. 
*Connect the activated buttery box and BM module, stack them together and finishing buildup. 
[[File:MicroduinoBuzzer-Equipment-ok.jpg|600px|center]]

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