How to Handle Servo Motor with Arduino

Servo motor is a DC motor that has an output feedback indicates the position of rotation of the motor. Servo motors are widely used as actuators requiring precise motor rotation position. If the ordinary DC motor can only be controlled speed and direction of rotation, the servo motors have an additional amount of parameters that can be controlled, which is a position based on the angle / degrees.

In this tutorial I will cite an experiment with micro-type servo motor SG90 (known as micro servo) that many available in the market. This is called micro servo because of its small size and need small amout of current / voltage. Specifications are approximately as follows:

SG90 Servo Motor Specs:

- Working voltage: 4.8 to 6 VDC
- Torque: 1.6 kg / cm
- Current: <500 mA
- Dimensions: 22 x 12.5 x 29.5 cm
- Weight: 9 g
- Rotation speed: 0.12 seconds / 60 degrees

Handle Servo Motor with Arduino Experiment

To handle the servo motor using the Arduino is easy enough, you may even be able to do it for less than 5 minutes! The key is usage of the library 'Servo.h' already provided by Arduino IDE. By declaring this library, you can create an object that has a method 'write (degrees)' with 'degrees' parameter is intended to show angle of rotation. For the above products, maximum angle is 1800, so you have a range of rotation angle between 00 - 1800 can be taken this kind of servo motors. By using this servo motors we have not talked again about the play direction (CW) or counter-clockwise (CCW) but the ‘angle’ of 00, 450, 900 and so on up to 1800. So, for example, if you issue the command ‘myservo.write (90);’ after ‘myservo.write (0);’ then the servo motor will move counter-clockwise. Then, if you issue the command ‘myservo.write (90);’ after ‘myservo.write command (180);’,  the servo motor will automatically move clockwise.

The position 0 s.d 180 degree is determined by the internal servo motor controller, and you simply give the command on the corner where the motor will rotate through the command ‘myservo.write (degrees);’

To begin the experiment, prepare components as follows:
- Arduino board (Uno or others).
- Motor servo (e.g. a Tower Pro  SG90 micro-servo)
- Jumper cables (3 pieces)

For servo motors, if you use the same type with mine then you'll find three wires:
- The color red is a power cable, connected to the Arduino 5V pin
- The color black / brown is ground wires, connected to the GND pin of Arduino board
- The color orange is the data cable / command, is connected to pin 9 Arduino (the other pins may be substituted)

Servo Motor - Arduino Wiring

Then jumper cable between the servo motor and Arduino with the configuration as above or can also be seen in the picture below

Servo Motor- Arduino Sketch

Once the prototype circuit is completed, it is time to fill the program handlers to Arduino sketch. Here they are:

#include <Servo.h>

Servo myservo; 
void setup()
void loop() 

Copy this Arduino sketch to your Arduino IDE, and upload the one to your Arduino board. If you don’t know how to do this, please read in this article.

Once the sketch is uploaded to the Arduino and if your wiring-connections are correct, then it should be the servo motor will now spin into a position that was written in the sketch with a delay of about 1 second (1000 ms). Note that the motor will back rotate in counter-clockwise to the start positions after reach maximal angle (1800) automatically. Congratz, you now able to handle a motor servo :). You can develop another advanced experiment based on simple experiment above. And if you want to rotate the motor more than 1800 (e.g. 3600 or full rotation) I'll tell you the technique in How to Control Servo Motor Speed with Arduino tutorial :)
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