How to use an Arduino LCD display

An LCD display can be a really useful part of your solution since it can shows a value from a sensor directly and also able to shows other messages. The following document gives you a brief introduction to Arduino LCD displays with defining how to connect and use with your Arduino and with Ozeki 10 as well. This guide also contains diagram and videos for a better understanding od Arduino LCD Display. So, let's start right now.

What is an LCD display?

Stands for "Liquid Crystal Display." LCD is a flat panel display technology commonly used in TVs and computer monitors. It is also used in screens for mobile devices, such as laptops, tablets, and smartphones.

How does an Arduino LCD Display work?

It has 16 pins and the first one from left to right is the Ground pin. The second pin is the VCC which we connect the 5 volts pin on the Arduino Board. Next is the Vo pin on which we can attach a potentiometer for controlling the contrast of the display. Next, The RS pin or register select pin is used for selecting whether we will send commands or data to the LCD. For example, if the RS pin is set on low state or zero volts, then we are sending commands to the LCD like: set the cursor to a specific location, clear the display, turn off the display and so on. And when RS pin is set on High state or 5 volts we are sending data or characters to the LCD.

Arduino LCD Display wiring diagram

wiring diagram of arduino lcd display
Figure 1 - Wiring diagram of Arduino LCD Display

How to use an Arduino LCD display in Ozeki

LCD Display connections can send characters to LCD Displays from any connection added to your Ozeki software. This connection supports HD44780 character LCD displays. You can get them in 16x1, 16x2 and 20x4 dimensions, which represents columns x rows. Try your LCD Display as you can see in the 3rd video, below. For easier connection please try the Ozeki Display Module. To use the LCD Display in Ozeki, you first need to download Ozeki Robot Developer. Ozeki Robot Developer will install the Arduino libraries needed to use this sensor efficiently.

Download Ozeki Robot Developer

Download Ozeki Robot Developer

After Ozeki Robot developer is installed, you need to upload the LCD Display control code to your Arduino. You can find the code and download instructions on the following pages. The upload process includes two steps: first you need to format the EEPROM of the arduino, then you need to upload the control code. The procedure is very simple, it only takes a few seconds.

Upload the LCD Display code to Arduino Uno
Upload the LCD Display code to Arduino Mega 2560
Upload the LCD Display code to Arduino Nano
Upload the LCD Display code to Ozeki Matrix
Upload the LCD Display code to Raspberry Pi

The arduino sensors and Ozeki will communicate over the USB port using the Ozeki LCD Display protocol. This protocol makes it possible for you to use the sensor directly on your PC. You will be able to control this sensor through the web based user interface or you will be able to communicate with it using Ozeki Chat. You can read more about chat control on the following page.

How to communicate with the LCD Display using chat

It is important to understand chat control, because when you build a robot, the way you wish to control this sensor is by sending and receiving messages. If you open the Ozeki Robot Developer app, you will see, who you can write a C#.Net program to work with this sensor.

Connection steps

  1. Wire the LCD display to the Arduino using the wiring diagram
  2. Connect the Arduino board into your computer
  3. Check the COM ports in Windows device list
  4. Open the Arduino application on your computer
  5. Upload example code to the microcontroller
  6. Open https://localhost:9515 in your browser
  7. Select the LCD Display from the connection list
  8. Write a test message to the screen of the LCD display

System overview

The system we suggest consists of an LCD display, that is wired to the analog port of your Arduino. The Arduino will be responsible for reading data from this device in real-time. The brain of the system will be running on a PC (Figure 2). On the PC, Ozeki 10 will be able to manage the communication. You can easily run Ozeki 10 using a webbrowser

system configuration of lcd display connecting to pc using arduino
Figure 2 - System configuration of LCD display connecting to PC using Arduino


  • HD44780 LCD display (16x1, 16x2 or 20x4)
  • Ozeki 10 installed on your computer
  • Programmable board (Arduino Mega/Nano/Uno, Ozeki Display Modul or Raspberry Pi)
  • If you do not use an Ozeki Display Modul than an 1kΩ and 7.2kΩ resistor is required
  • USB cable is needed between Arduino Mega/Nano/Uno, Ozeki Display Modul and your computer

Step 1 - Wire the LCD display to your Arduino

You can see how to wire the HD44780 LCD display to any of the following boards:

After wiring, please plug the board to your computer!

Step 2 - Upload code to the microcontroller

(Here is the code to upload)

Step 3 - Start Ozeki 10 to try the LCD display

Step 4 - Configure your LCD display in Ozeki 10

In order to configure your LCD display (attached to your Arduino) in Ozeki 10, that is installed on your computer, you need to open the graphical user interface (GUI) of Ozeki 10. You can open the GUI by entering the URL of the computer into your webbrowser. For example, if our PC has an IP address of, we would enter into our webbrowser.

Step 5 - Understand the LCD display protocol

The LCD Display Controller can communicate with Ozeki through the following protocol.


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