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Arduino - Sound Sensor - Servo Motor
In this tutorial, we'll explore how to utilize the sound sensor to control servo motor. Specifically, we'll delve into two exciting applications:
- Sound switch: When sound is detected (e.g knock), the Arduino rotates servo motor to 90 degree if it's in 0 degree, and 0 degree if it's in 90 degree.
- Sound-activated relay: Upon detecting sound, the Arduino rotates servo motor to 90 degree for a specific period of time, and then rotates back to 0 degree.
Hardware Required
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Please note: These are Amazon affiliate links. If you buy the components through these links, We will get a commission at no extra cost to you. We appreciate it.
About Servo Motor and Sound Sensor
If you do not know about servo motor and sound sensor (pinout, how it works, how to program ...), learn about them in the following tutorials:
Wiring Diagram
This image is created using Fritzing. Click to enlarge image
Arduino Code - Sound Switch toggles Angle of Servo Motor
The below code toggles the angle of servo motor between 0 and 90 degree each time the sound is detected.
/*
* Created by ArduinoGetStarted.com
*
* This example code is in the public domain
*
* Tutorial page: https://arduinogetstarted.com/tutorials/arduino-sound-sensor-servo-motor
*/
#include <Servo.h>
#define SENSOR_PIN A0 // Arduino pin connected to sound sensor's pin
#define SERVO_PIN 9 // Arduino pin connected to servo motor's pin
Servo servo; // create servo object to control a servo
// variables will change:
int angle = 0; // the current angle of servo motor
int lastSoundState; // the previous state of sound sensor
int currentSoundState; // the current state of sound sensor
void setup() {
Serial.begin(9600); // initialize serial
pinMode(SENSOR_PIN, INPUT); // set arduino pin to input mode
servo.attach(SERVO_PIN); // attaches the servo on pin 9 to the servo object
servo.write(angle);
currentSoundState = digitalRead(SENSOR_PIN);
}
void loop() {
lastSoundState = currentSoundState; // save the last state
currentSoundState = digitalRead(SENSOR_PIN); // read new state
if (lastSoundState == HIGH && currentSoundState == LOW) { // state change: HIGH -> LOW
Serial.println("The sound has been detected");
// change angle of servo motor
if (angle == 0)
angle = 90;
else if (angle == 90)
angle = 0;
// control servo motor arccoding to the angle
servo.write(angle);
}
}
Quick Steps
- Connect Arduino to PC via USB cable
- Open Arduino IDE, select the right board and port
- Copy the above code and open with Arduino IDE
- Click Upload button on Arduino IDE to upload code to Arduino
- Clap your hand in front of the sound sensor
- See the change of servo motor
Arduino Code - Sound-activated Servo Motor for a period of time
The below code rotates the servo motor to 90 degree for a period of time when the sound is detected. After the period of time, the servo motor is rotated back to 0 degree.
/*
* Created by ArduinoGetStarted.com
*
* This example code is in the public domain
*
* Tutorial page: https://arduinogetstarted.com/tutorials/arduino-sound-sensor-servo-motor
*/
#include <Servo.h>
#define SENSOR_PIN A0 // Arduino pin connected to sound sensor's pin
#define SERVO_PIN 9 // Arduino pin connected to servo motor's pin
#define TIME_PERIOD 5000 // in milliseconds
Servo servo; // create servo object to control a servo
// variables will change:
int lastSoundState; // the previous state of sound sensor
int currentSoundState; // the current state of sound sensor
void setup() {
Serial.begin(9600); // initialize serial
pinMode(SENSOR_PIN, INPUT); // set arduino pin to input mode
servo.attach(SERVO_PIN); // attaches the servo on pin 9 to the servo object
servo.write(0);
currentSoundState = digitalRead(SENSOR_PIN);
}
void loop() {
lastSoundState = currentSoundState; // save the last state
currentSoundState = digitalRead(SENSOR_PIN); // read new state
if (lastSoundState == HIGH && currentSoundState == LOW) { // state change: HIGH -> LOW
Serial.println("The sound has been detected");
servo.write(90); // control servo motor to 90 degree
delay(TIME_PERIOD);
servo.write(0); // control servo motor to 0 degree
}
}
Please take note that the code mentioned above utilizes the delay() function for simplicity. However, if you incorporate additional code, it may get blocked during the delay time. To address this, the following code implements a non-blocking approach using the millis() function instead of delay to prevent blocking.
/*
* Created by ArduinoGetStarted.com
*
* This example code is in the public domain
*
* Tutorial page: https://arduinogetstarted.com/tutorials/arduino-sound-sensor-servo-motor
*/
#include <Servo.h>
#define SENSOR_PIN A0 // Arduino pin connected to sound sensor's pin
#define SERVO_PIN 9 // Arduino pin connected to servo motor's pin
#define TIME_PERIOD 5000 // in milliseconds
Servo servo; // create servo object to control a servo
// variables will change:
int lastSoundState; // the previous state of sound sensor
int currentSoundState; // the current state of sound sensor
unsigned long lastTime; // the current state of sound sensor
int angle = 0;
void setup() {
Serial.begin(9600); // initialize serial
pinMode(SENSOR_PIN, INPUT); // set arduino pin to input mode
servo.attach(SERVO_PIN); // attaches the servo on pin 9 to the servo object
servo.write(angle);
currentSoundState = digitalRead(SENSOR_PIN);
}
void loop() {
lastSoundState = currentSoundState; // save the last state
currentSoundState = digitalRead(SENSOR_PIN); // read new state
if (lastSoundState == HIGH && currentSoundState == LOW) { // state change: HIGH -> LOW
Serial.println("The sound has been detected");
angle = 90;
servo.write(angle); // control servo motor to 90 degree
lastTime = millis();
}
if (angle == 90 && (millis() - lastTime) > TIME_PERIOD) {
angle = 0;
servo.write(angle); // control servo motor to 0 degree
}
}
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