ลำโพงแบบ Passive Buzzer 3V 5V

• Uses passive buzzer that needs to be driven by a PWM signal
• 5V operation nominal.  The signal can range from 0-5V in practice.
• No oscillation source, need square wave (frequency 2K-5K ) to drive.

/*
ตัวอย่าง Code passive buzzer 
สร้างเสียงตามความถี่ต่างๆ ไล่ไปเรื่อยๆ
*/

int TonePin = 6;               // Pin connected to Passive Buzzer
int Freq = 500;                // Frequency to play buzzer at

// the setup function runs once when you press reset or power the board
void setup() {
 pinMode(TonePin, OUTPUT);      // Buzzer
}

// the loop function runs over and over again forever
void loop() {
tone(TonePin,Freq);            // Send tone to buzzer

 delay(1000);                  // wait for 1 Sec 
 Freq = Freq + 500;            // Increment tone by 200 Hz
 if (Freq > 4000) Freq = 500;  // Go up to 4KHz then restart back at 500Hz
}