Output Devices

Assignment 12

Here we go..

Output Devices !!

The goal of this week is to learn about output devices and make some applications. The difference between input and output devices are:

Input Device
  • Function: To give information to the computer for processing.
  • Successions: Used First.
  • procession: By the user.

  • Output Device
  • Function: To provide the user with information.
  • Successions: Used Second.
  • procession: By the computer.

  • Group Assignment

    In this assignment we were asked to measure the power consumption of an output device.

    You can check the group assignment from this link : Group Assignment.

    Individual Assignment

    We are supposed to add an output device to a microcontroller board that we have designed, and program it to do something. As I said in the input device assignment, I’m going to use an arduino to test the devices.

    Let’s talk more about output devices!

    What is an output device ?

    An Output device is a device that receives data (signal) from a computer/Arduino for display, projection, or physical reproduction.

    Output devices examples:
  • LCD Display.
  • LED.
  • Servo motor.
  • Buzzer.
  • Relay.

  • In this assignment, I’m going to use:
  • LCD display.
  • Servo motor.

  • LCD - Liquid Crystal Display

    What is LCD display ?

    LCD is an output electronic display module which uses liquid crystal to produce a visible image.

    16×2 LCD Specifications:

  • Operating Voltage: 5V.
  • Controller: Hitachi HD44780 LCD controller.
  • Screen Resolution: 2-Lines x 16 characters.
  • Character Resolution: 5 x 8 pixels.
  • Module Dimensions: 80 x 36 x 12 mm.
  • Viewing Area Dimensions: 64.5 x 16.4 mm.

  • LCD display parts:

    The LCD has 16 connection pins, numbered 1-16 from left to right.

    16×2 LCD pinout:
  • VCC: Signal ground. Connected to GND Arduino.
  • VDD: Logic power for LCD. Connecteed to 5V Arduino.
  • V0: Contrast adjustment. Connected to 10 K ohm potentiometer.
  • RS: Register select signal Connected to Pin 2 Arduino.
  • R/W: Read/Write select signa. Connected to GND Arduino.
  • E: Operation enable signal. Connected to Pin in Arduino.
  • D0 - D7: Data bus lines used for 8-bit mode. Not connected to anything.
  • D4 - D7: Data bus lines used for 4-bit mode. Connected to Pins in Arduino.
  • A (LED+): Anode for LCD backlight. Connected to 5V Arduino.
  • K (LED-): Cathode for LCD backlight. Connected to Pin in GND Arduino.

  • How does LCD display work ?

    Let’s Make it !

    I’m going to write some words by using LCD.

  • Hello World
  • FAB Academy
  • How To Make Almost Anything.
  • Norah Alghofaili

  • The Components:
  • Arduino UNO.
  • Breadboard.
  • 16*2 LCD display.
  • Potentiometer.
  • Jumper wires.
  • Resistors 220 Ohm.

  • What is a potentiometer ?

    A potentiometer is a variable resistor used to adjust the contrast level of the LCD screen.

    Let’s Connect the components !

    The Circuit

    Ops! Ops ! I faced this issue while using a tinkercad to simulate the LCD. The problem is LCD backlight was 23.7 kA while maximum 20 mA. To fix this issue I added a resistor 220 Ohm then it works !

    Let’s Program !

    1. lets

    I faced some problems after uploading the code. The code has been done but the LCD is not working!!

  • I checked the connection to make sure it’s right. I noticed that I did not connect pin15 and pin16 that is why the LCD is not working because Pin15 and Pin16 are the LEDs of the LCD.
  • After I connected Pin15 and Pin16, the LCD light was working but the letters were not shown.

  • I rechecked the connection and the code to figure out the problem. YES I FOUND IT !

  • I connected pin D3 in the LCD to Pin 5 in the arduino rather than pin D4. So, I changed it to Pin D4.
  • In the code I wrote pin 10 and it should be 11.


    Potentiometer Test

    LCD Display Arduino Test

    LCD Display PCB Test

    I LOVE LCD DISPLAY !!!! So, I wanna make another application.

    More Practice !

    When I searched about LCD display applications I found that I can make different types of gaming in this amazing output device. I love gaming! It’s so fun to make a Jumping Jack game by using the following components:

  • Arduino UNO.
  • Breadboard.
  • 16*2 LCD display.
  • Potentiometer.
  • Push Button.
  • Jumper wires.
  • Resistors 220 ohm.

  • Let’s Connect the components !

    The circuit

    Let’s Program !

    The Code

    The Video

    Whoooooo It’s Working! LET’S PLAY !!

    Servo Motor

    The second output device that I’m going to test is a servo motor.

    What is Servo Motor ?

    A servo motor is an electrical output device which can push or rotate an object with different directions/angles.

    Servo Motor Parts:


    1. Mounting tabs.

    2. Output shaft.

    3. Servo horn.

    4. Connector.

    5. Cable.

    6. Connector.


    1. Motor.

    2. Gearbox.

    3. Position sensor.

    4. Motor control electronics.

    How does servo motor work ?

    Servos are controlled by sending them a pulse of variable width. The control wire is used to send this pulse.

    Applications in our life :

    There are many aplications in our life using servo motor such as :

  • Gate system.
  • Fan.

  • Servo Pinout:

  • Control: is input for the control system.
  • 5V: is a positive voltage that powers the servo.
  • GND: is a common ground for both the motor and logic

  • Let’s Make it !

    I’m going to control the servo motor by using push button.

    The components :
  • Arduino UNO.
  • Breadboard.
  • Servo Motor.
  • Push Button.
  • Resistor 220 Ohm.
  • Jumper wires.

  • Let's connect the componants!

    Let’s program !
    Now, I open Arduino IDE to upload the code. The bellow code will work as follow:

    1. I used the (h.servo) library by going to Sketch > Include Library > Servo.

    #include Servo.h 

    2. After connecting the wires, I dintified the pin ( ButtonPin = 9 ), ( Val means the value of the direction ).

    const int buttonPin = 9;
    int val;
    int buttonState = 0;

    3. In the void setup, I dintified the control pin of the servo (wired up to pin 2 in Arduino) and the pinMode of the push button as INPUT.

    void setup()
      pinMode(buttonPin, INPUT);       

    4. In the void loop, I idintified the value of the servo direction as (val=180). If I press on the push button the servo motor will rotate 180 degree.

    void loop()
      buttonState = digitalRead(buttonPin);
      if (buttonState == HIGH) {     
        val = 180; 
      else {
        val = 0;

    The code

    Arduino Test :

    In this video, I tried to test the servo by using different values ( 180 degree & 90 degree ).

    if (buttonState == HIGH) {     
        val = 180; 


    if (buttonState == HIGH) {     
        val = 90; 

    I really enjoy input and output devices assignments because I tried to test as much as I can on different devices. I learned about Ultrasonic, LED, LDR, LED matrix module, LCD, Potentiometer and Servo motor.I don't want these assignments to finish!!!

    Code Files:
  • Arduino IDE : LCD Text Code.
  • Arduino IDE : LCD Jumping Jack Game Code.
  • Arduino IDE : Servo Motor Code.