Driving a Servo Motor — SIK Circuit 8

Control a servo motor to sweep through positions. Learn about the Servo library, include directives, and how to precisely control motor position from 0 to 180 degrees.

Instructions

Parts & Introduction

A servo motor can be precisely positioned between 0 and 180 degrees. Unlike a regular motor that just spins, servos hold their position — making them perfect for robotics, pan/tilt mechanisms, and control surfaces. This experiment introduces the Servo library.

Parts Needed

1x Arduino Uno + USB cable
1x Breadboard
1x Servo Motor (with 3-pin header)
8x Jumper Wires

The servo has three wires: Red (power), Black (ground), White (signal).

Hardware Hookup

Wiring Instructions

Connect 3 jumper wires to the servo's female 3-pin header for breadboarding.
Connect the Red wire to 5V.
Connect the Black wire to GND.
Connect the White wire (signal) to Digital Pin 9.

Power Note: Servos draw significant current. If the servo twitches and the Arduino resets, use a wall adapter instead of USB power, or power the servo from a separate 5V supply.

Arduino Code

Open the Arduino IDE and upload the following sketch to your Arduino board.

servo_motor.inoarduino

/*
SparkFun Inventor's Kit
Example sketch 08 — SINGLE SERVO

Sweep a servo back and forth through its full range of motion.

Hardware connections:
  Servo RED wire (power) to 5V
  Servo WHITE wire (signal) to digital pin 9
  Servo BLACK wire (ground) to GND

This code is completely free for any use.
*/

#include <Servo.h>

Servo servo1;

void setup()
{
  servo1.attach(9);
}

void loop()
{
  int position;

  // Quick moves to specific positions
  servo1.write(90);    // Go to 90 degrees
  delay(1000);
  servo1.write(180);   // Go to 180 degrees
  delay(1000);
  servo1.write(0);     // Go to 0 degrees
  delay(1000);

  // Slow sweep to 180 degrees (2-degree steps)
  for(position = 0; position < 180; position += 2)
  {
    servo1.write(position);
    delay(20);
  }

  // Slow sweep back to 0 degrees (1-degree steps)
  for(position = 180; position >= 0; position -= 1)
  {
    servo1.write(position);
    delay(20);
  }
}

Test & Experiment

What You Should See

The servo quickly moves to 90°, 180°, and 0° (1 second each), then slowly sweeps from 0° to 180° and back.

Troubleshooting

Servo not moving: Even with colored wires, it's easy to plug a servo in backwards. Check connections.
Twitching/resetting: The servo draws too much power from USB. Use a wall adapter or separate power supply.

Experiments to Try

Add a potentiometer (from Circuit 2) to control servo position with a knob.
Change the step size and delay to experiment with speed and smoothness.
Build a simple pan/tilt mechanism with two servos.

Materials

•SparkFun Inventor's Kit - V3.2 - 1 kitNOK 999.20
View
•Arduino Uno R3 - 1 piecePlaceholder
View
•Breadboard - 1 piecePlaceholder
View
•Servo Motor - 1 piecePlaceholder
View
•Jumper Wires - 8 piecessNOK 39.20
View

Tools Required

Computer with Arduino IDE

CC0 Public Domain

This blueprint is released under CC0. You are free to copy, modify, distribute, and use this work for any purpose, without asking permission.

Support the Maker by purchasing products through their Blueprint where they earn a Maker Commission set by Vendors, or create a new iteration of this Blueprint and include it as a connection in your own Blueprint to share revenue.

Discussion

(0)

Loading comments...