6. Servo

This tutorial will teach you the basics of using a servo motor. The servo motor can be used for a variety of purposes including robotics, aerospace, and industrial automation! Servo motorscan regulate force and control speed as well.

Materials

Component	Image
Breadboard
Jumper wires
Arduino Uno R4 Minima
Micro servo (180 degrees, 9g)
Potentiometer (10k)

Part 1. Basic Movements

1. Attach the servo horn to the servo motor by fastening it securely to the output shaft with screws.

2. Make the following connections using the breadboard and jumper wires.

Connections

• Black wire to GND
• Red wire to 5V
• Orange wire to pin 9

3. Upload the following code into your Arduino IDE.

Code

#include <Servo.h>

Servo myservo;

void setup() {
  myservo.attach(9); // Attach the servo to digital pin 9
  myservo.write(90); // Move the servo to the center position (90 degrees)
}

void loop() {
  myservo.write(90); // Move the servo to the center position (90 degrees)
  delay(1000);
  myservo.write(30); // Move the servo to 30 degrees
  delay(1000);
  myservo.write(90); // Move the servo back to 90 degrees
  delay(1000);
  myservo.write(150); // Move the servo to 150 degrees
  delay(1000);
}

4. Upload the code to your Arduino and run.

5. Watch the servo run periodically! You can change the delay time and cutomize the positioning of the servo.

Part 2. Knob

1. Connect one of the outer pins on the potentiometer to 5V and the other to GND.

2. Connect the inner (middle) pin to analog pin A0.

3. Leave the servo motor connected the same as in part 1.

4. Copy the following code into your Arduino IDE:

#include <Servo.h>

Servo myservo;  // create servo object to control a servo

const int potpin = A0;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin

void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  val = map(val, 0, 1023, 0, 180);     // scale it to use it with the servo (value between 0 and 180)
  myservo.write(val);                  // sets the servo position according to the scaled value
  delay(15);                           // waits for the servo to get there
}

5. Upload the code to your arduino and run it.

6. Twist the potentiometer and watch the servo motor run!

Part 3. Sweep

1. Remove the potentiometer from the breadboarf and restore the wiring connections from part 1:

Connections

• Black wire to GND
• Red wire to 5V
• Orange wire to pin 9

2. Paste the following code to the Arduino IDE:

#include <Servo.h>

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position

void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
}

3. Upload the code to the arduino and run it.

4. Watch the servo motor rotate back and forth!

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5. Ball Switch	7. Ultrasonic Sensor