======Oak: Making Noise with the Buzzer======

This lesson will show you how to connect the 3.3v Active Buzzer to your Oak and make it beep morse code.

=====Components Used:=====

^ Part       ^ Quantity          ^Identification^
| Oak with soldered headers |1| |
|  Breadboard| 1| |
|  3.3v Active Buzzer | 1| |
|  M to M 30cm Jumper Wire| 2| Red, Black|

=====Concepts:=====

**Piezo Buzzers**: In this lesson we will be using a Piezo buzzer to make sound. We will be achieving this by turning it on and off, much like an [[oak:tutorials:leds|LED]].

{{:oak:tutorials:buzzerexample.jpg?direct&300|A piezo buzzer}}

A piezo buzzer is a sandwich of two different conductive metals. When voltage is applied to the two different metals it bends, creating waves in air - which we call sound. They are usually small and circular and can be found in anything that provides an annoying beep.

We can make a piezo buzzer beep like this in code:
<code>
 // turn pin 1 "on" by making the voltage HIGH)
  digitalWrite(1, HIGH);
</code>
Where digitalWrite(1, HIGH); means turn Pin1 fully on. Don't forget to turn it off again!

=====Circuit:=====

{{:oak:tutorials:buzzer.png?direct&200|Buzzer}}

Remember that when connecting a buzzer, you must pay attention to the (+) sign on the top of the buzzer casing. The (+) sign represents the positive connector and is where the red wire from pin 2 must go. If you get this backwards your buzzer may stop working.

=====Code:=====

<code>
//set the buzzer pin
int buzzer = 2;

// the setup function runs once when you reset or power the board
void setup() {
  // initialize buzzer as an output.
  pinMode(buzzer, OUTPUT);
  
}

// the loop function runs over and over again forever
void loop() {
  // make 3 dots to make an S
  for (int a = 0; a < 3; a++) {
    dot();
  }
  // wait 100 miliseconds after the first S
  delay(100);
  // make 3 dashes to make an o
  for (int b = 0; b < 3; b++) {
    dash();
  }
  // wait 100 miliseconds after the o
  delay(100);
  // make 3 dots to make an S
  for (int c = 0; c < 3; c++) {
    dot();
  }
  //wait 5 seconds before playing again
  delay(5000);
}

// make a dot noise
void dot()
{
  //turn on the buzzer
  digitalWrite(buzzer, HIGH);
  delay(100);
  // turn off the buzzer
  digitalWrite(buzzer, LOW);
  delay(100);  
}

// make a dash noise
void dash()
{
  // turn on the buzzer
  digitalWrite(buzzer, HIGH);
  delay(300);
  // turn off the buzzer
  digitalWrite(buzzer, LOW);
  delay(100);
}
</code>

In this example, we create two separate functions //dot()// and //dash()// and use them in for loops to save us having to write the same code over and over again. We also use a variable //buzzer// to declare which pin we are using for the buzzer.

//dot()// and //dash()// turn on and off the buzzer with different timings to simulate a morse code dot and dash using the //delay()// function which tells the Oak to pause for that many milliseconds.

=====Conclusion:=====

With this newfound power, perhaps you could make an internet connected morse code system to read out important tweets or secret messages from your friends.