Passive buzzer (beeper) - KY-006

Buzzer is an integrated structure of electronic transducers, DC power supply, widely used in computers, printers, copiers, alarms, electronic toys, automotive electronic equipment, telephones, timers and other electronic products for sound devices . Active buzzer 5V Rated power can be directly connected to a continuous sound, this section dedicated sensor expansion module and the Arduino board in combination, can complete a simple circuit design, to "plug and play."
int buzzer = 11 ;/ / setting controls the digital IO foot buzzer
void setup ()
{
  pinMode (buzzer, OUTPUT) ;/ / set the digital IO pin mode, OUTPUT to output
}
void loop ()
{
  unsigned char i, j ;/ / define variables
  while (1)
  {
for (i = 0; i <80; i + +) / / outputs a frequency sound
  {
   digitalWrite (buzzer, HIGH) ;/ / send voice
     delay (1) ;/ / Delay 1ms
   digitalWrite (buzzer, LOW) ;/ / do not send voice
  delay (1) ;/ / delay ms
   }
    for (i = 0; i <500; i + +) / / output to another frequency sound
     {
       digitalWrite (buzzer, HIGH) ;/ / send voice
       delay (2) ;/ / delay 2ms
       digitalWrite (buzzer, LOW) ;/ / do not send voice
       delay (2) ;/ / delay 2ms
     }
   }
}