simple lcd display arduino in stock

In this Arduino tutorial we will learn how to connect and use an LCD (Liquid Crystal Display)with Arduino. LCD displays like these are very popular and broadly used in many electronics projects because they are great for displaying simple information, like sensors data, while being very affordable.

You can watch the following video or read the written tutorial below. It includes everything you need to know about using an LCD character display with Arduino, such as, LCD pinout, wiring diagram and several example codes.

An LCD character display is a unique type of display that can only output individual ASCII characters with fixed size. Using these individual characters then we can form a text.

If we take a closer look at the display we can notice that there are small rectangular areas composed of 5×8 pixels grid. Each pixel can light up individually, and so we can generate characters within each grid.

The number of the rectangular areas define the size of the LCD. The most popular LCD is the 16×2 LCD, which has two rows with 16 rectangular areas or characters. Of course, there are other sizes like 16×1, 16×4, 20×4 and so on, but they all work on the same principle. Also, these LCDs can have different background and text color.

It has 16 pins and the first one from left to right is the Groundpin. The second pin is the VCCwhich 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 RSpin 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.

Next comes the R/W pin which selects the mode whether we will read or write to the LCD. Here the write mode is obvious and it is used for writing or sending commands and data to the LCD. The read mode is used by the LCD itself when executing the program which we don’t have a need to discuss about it in this tutorial.

Next is the E pin which enables the writing to the registers, or the next 8 data pins from D0 to D7. So through this pins we are sending the 8 bits data when we are writing to the registers or for example if we want to see the latter uppercase A on the display we will send 0100 0001 to the registers according to the ASCII table. The last two pins A and K, or anode and cathode are for the LED back light.

After all we don’t have to worry much about how the LCD works, as the Liquid Crystal Library takes care for almost everything. From the Arduino’s official website you can find and see the functions of the library which enable easy use of the LCD. We can use the Library in 4 or 8 bit mode. In this tutorial we will use it in 4 bit mode, or we will just use 4 of the 8 data pins.

We will use just 6 digital input pins from the Arduino Board. The LCD’s registers from D4 to D7 will be connected to Arduino’s digital pins from 4 to 7. The Enable pin will be connected to pin number 2 and the RS pin will be connected to pin number 1. The R/W pin will be connected to Ground and theVo pin will be connected to the potentiometer middle pin.

We can adjust the contrast of the LCD by adjusting the voltage input at the Vo pin. We are using a potentiometer because in that way we can easily fine tune the contrast, by adjusting input voltage from 0 to 5V.

Yes, in case we don’t have a potentiometer, we can still adjust the LCD contrast by using a voltage divider made out of two resistors. Using the voltage divider we need to set the voltage value between 0 and 5V in order to get a good contrast on the display. I found that voltage of around 1V worked worked great for my LCD. I used 1K and 220 ohm resistor to get a good contrast.

There’s also another way of adjusting the LCD contrast, and that’s by supplying a PWM signal from the Arduino to the Vo pin of the LCD. We can connect the Vo pin to any Arduino PWM capable pin, and in the setup section, we can use the following line of code:

It will generate PWM signal at pin D11, with value of 100 out of 255, which translated into voltage from 0 to 5V, it will be around 2V input at the Vo LCD pin.

Here’s a simple code through which we can explain the working principle of the Liquid Crystal library. This is the code of the first example from the video:

First thing we need to do is it insert the Liquid Crystal Library. We can do that like this: Sketch > Include Library > Liquid Crystal. Then we have to create an LC object. The parameters of this object should be the numbers of the Digital Input pins of the Arduino Board respectively to the LCD’s pins as follow: (RS, Enable, D4, D5, D6, D7). In the setup we have to initialize the interface to the LCD and specify the dimensions of the display using the begin()function.

The cursor() function is used for displaying underscore cursor and the noCursor() function for turning off. Using the clear() function we can clear the LCD screen.

In case we have a text with length greater than 16 characters, we can scroll the text using the scrollDisplayLeft() orscrollDisplayRight() function from the LiquidCrystal library.

We can choose whether the text will scroll left or right, using the scrollDisplayLeft() orscrollDisplayRight() functions. With the delay() function we can set the scrolling speed.

So, we have covered pretty much everything we need to know about using an LCD with Arduino. These LCD Character displays are really handy for displaying information for many electronics project. In the examples above I used 16×2 LCD, but the same working principle applies for any other size of these character displays.

I hope you enjoyed this tutorial and learned something new. Feel free to ask any question in the comments section below and don’t forget to check out my full collection of 30+ Arduino Projects.

In this tutorial, I’ll explain how to set up an LCD on an Arduino and show you all the different ways you can program it. I’ll show you how to print text, scroll text, make custom characters, blink text, and position text. They’re great for any project that outputs data, and they can make your project a lot more interesting and interactive.

The display I’m using is a 16×2 LCD display that I bought for about $5. You may be wondering why it’s called a 16×2 LCD. The part 16×2 means that the LCD has 2 lines, and can display 16 characters per line. Therefore, a 16×2 LCD screen can display up to 32 characters at once. It is possible to display more than 32 characters with scrolling though.

The code in this article is written for LCD’s that use the standard Hitachi HD44780 driver. If your LCD has 16 pins, then it probably has the Hitachi HD44780 driver. These displays can be wired in either 4 bit mode or 8 bit mode. Wiring the LCD in 4 bit mode is usually preferred since it uses four less wires than 8 bit mode. In practice, there isn’t a noticeable difference in performance between the two modes. In this tutorial, I’ll connect the LCD in 4 bit mode.

Here’s a diagram of the pins on the LCD I’m using. The connections from each pin to the Arduino will be the same, but your pins might be arranged differently on the LCD. Be sure to check the datasheet or look for labels on your particular LCD:

Also, you might need to solder a 16 pin header to your LCD before connecting it to a breadboard. Follow the diagram below to wire the LCD to your Arduino:

All of the code below uses the LiquidCrystal library that comes pre-installed with the Arduino IDE. A library is a set of functions that can be easily added to a program in an abbreviated format.

In order to use a library, it needs be included in the program. Line 1 in the code below does this with the command #include . When you include a library in a program, all of the code in the library gets uploaded to the Arduino along with the code for your program.

Now we’re ready to get into the programming! I’ll go over more interesting things you can do in a moment, but for now lets just run a simple test program. This program will print “hello, world!” to the screen. Enter this code into the Arduino IDE and upload it to the board:

There are 19 different functions in the LiquidCrystal library available for us to use. These functions do things like change the position of the text, move text across the screen, or make the display turn on or off. What follows is a short description of each function, and how to use it in a program.

TheLiquidCrystal() function sets the pins the Arduino uses to connect to the LCD. You can use any of the Arduino’s digital pins to control the LCD. Just put the Arduino pin numbers inside the parentheses in this order:

This function sets the dimensions of the LCD. It needs to be placed before any other LiquidCrystal function in the void setup() section of the program. The number of rows and columns are specified as lcd.begin(columns, rows). For a 16×2 LCD, you would use lcd.begin(16, 2), and for a 20×4 LCD you would use lcd.begin(20, 4).

This function clears any text or data already displayed on the LCD. If you use lcd.clear() with lcd.print() and the delay() function in the void loop() section, you can make a simple blinking text program:

Similar, but more useful than lcd.home() is lcd.setCursor(). This function places the cursor (and any printed text) at any position on the screen. It can be used in the void setup() or void loop() section of your program.

The cursor position is defined with lcd.setCursor(column, row). The column and row coordinates start from zero (0-15 and 0-1 respectively). For example, using lcd.setCursor(2, 1) in the void setup() section of the “hello, world!” program above prints “hello, world!” to the lower line and shifts it to the right two spaces:

You can use this function to write different types of data to the LCD, for example the reading from a temperature sensor, or the coordinates from a GPS module. You can also use it to print custom characters that you create yourself (more on this below). Use lcd.write() in the void setup() or void loop() section of your program.

The function lcd.noCursor() turns the cursor off. lcd.cursor() and lcd.noCursor() can be used together in the void loop() section to make a blinking cursor similar to what you see in many text input fields:

Cursors can be placed anywhere on the screen with the lcd.setCursor() function. This code places a blinking cursor directly below the exclamation point in “hello, world!”:

This function creates a block style cursor that blinks on and off at approximately 500 milliseconds per cycle. Use it in the void loop() section. The function lcd.noBlink() disables the blinking block cursor.

This function turns on any text or cursors that have been printed to the LCD screen. The function lcd.noDisplay() turns off any text or cursors printed to the LCD, without clearing it from the LCD’s memory.

This function takes anything printed to the LCD and moves it to the left. It should be used in the void loop() section with a delay command following it. The function will move the text 40 spaces to the left before it loops back to the first character. This code moves the “hello, world!” text to the left, at a rate of one second per character:

Like the lcd.scrollDisplay() functions, the text can be up to 40 characters in length before repeating. At first glance, this function seems less useful than the lcd.scrollDisplay() functions, but it can be very useful for creating animations with custom characters.

lcd.noAutoscroll() turns the lcd.autoscroll() function off. Use this function before or after lcd.autoscroll() in the void loop() section to create sequences of scrolling text or animations.

This function sets the direction that text is printed to the screen. The default mode is from left to right using the command lcd.leftToRight(), but you may find some cases where it’s useful to output text in the reverse direction:

This code prints the “hello, world!” text as “!dlrow ,olleh”. Unless you specify the placement of the cursor with lcd.setCursor(), the text will print from the (0, 1) position and only the first character of the string will be visible.

This command allows you to create your own custom characters. Each character of a 16×2 LCD has a 5 pixel width and an 8 pixel height. Up to 8 different custom characters can be defined in a single program. To design your own characters, you’ll need to make a binary matrix of your custom character from an LCD character generator or map it yourself. This code creates a degree symbol (°):

This tutorial includes everything you need to know about controlling a character LCD with Arduino. I have included a wiring diagram and many example codes. These displays are great for displaying sensor data or text and they are also fairly cheap.

The first part of this article covers the basics of displaying text and numbers. In the second half, I will go into more detail on how to display custom characters and how you can use the other functions of the LiquidCrystal Arduino library.

As you will see, you need quite a lot of connections to control these displays. I therefore like to use them with an I2C interface module mounted on the back. With this I2C module, you only need two connections to control the LCD. Check out the tutorial below if you want to use an I2C module as well:

These LCDs are available in many different sizes (16×2 1602, 20×4 2004, 16×1 etc.), but they all use the same HD44780 parallel interface LCD controller chip from Hitachi. This means you can easily swap them. You will only need to change the size specifications in your Arduino code.

For more information, you can check out the datasheets below. The 16×2 and 20×4 datasheets include the dimensions of the LCD and in the HD44780 datasheet you can find more information about the Hitachi LCD driver.

Most LCDs have a built-in series resistor for the LED backlight. You should find it on the back of the LCD connected to pin 15 (Anode). If your display doesn’t include a resistor, you will need to add one between 5 V and pin 15. It should be safe to use a 220Ω resistor, but this value might make your display a bit dim. You can check the datasheet for the maximum current rating of the backlight and use this to select an appropriate resistor value.

After you have wired up the LCD, you will need to adjust the contrast of the display. This is done by turning the 10 kΩ potentiometer clockwise or counterclockwise.

Plug in the USB connector of the Arduino to power the LCD. You should see the backlight light up. Now rotate the potentiometer until one (16×2 LCD) or 2 rows (20×4 LCD) of rectangles appear.

In order to control the LCD and display characters, you will need to add a few extra connections. Check the wiring diagram below and the pinout table from the introduction of this article.

We will be using the LCD in 4-bit mode, this means you don’t need to connect anything to D0-D3. The R/W pin is connected to ground, this will pull the pin LOW and set the LCD to WRITE mode.

To control the LCD we will be using the LiquidCrystal library. This library should come pre-installed with the Arduino IDE. You can find it by going to Sketch > Include Library > LiquidCrystal.

The example code below shows you how to display a message on the LCD. Next, I will show you how the code works and how you can use the other functions of the LiquidCrystal library.

After including the library, the next step is to create a new instance of the LiquidCrystal class. The is done with the function LiquidCrystal(rs, enable, d4, d5, d6, d7). As parameters we use the Arduino pins to which we connected the display. Note that we have called the display ‘lcd’. You can give it a different name if you want like ‘menu_display’. You will need to change ‘lcd’ to the new name in the rest of the sketch.

In the loop() the cursor is set to the third column and first row of the LCD with lcd.setCursor(2,0). Note that counting starts at 0, and the first argument specifies the column. If you do not specify the cursor position, the text will be printed at the default home position (0,0) if the display is empty, or behind the last printed character.

Next, the string ‘Hello World!’ is printed with lcd.print("Hello World!"). Note that you need to place quotation marks (” “) around the text. When you want to print numbers or variables, no quotation marks are necessary.

The LiquidCrystal Arduino library has many other built-in functions which you might find useful. You can find an overview of them below with explanation and some code snippets.

Clears the LCD screen and positions the cursor in the upper-left corner (first row and first column) of the display. You can use this function to display different words in a loop.

This function turns off any text or cursors printed to the LCD. The text/data is not cleared from the LCD memory. This means it will be shown again when the function display() is called.

Scrolls the contents of the display (text and cursor) one space to the left. You can use this function in the loop section of the code in combination with delay(500), to create a scrolling text animation.

This function turns on automatic scrolling of the LCD. This causes each character output to the display to push previous characters over by one space. If the current text direction is left-to-right (the default), the display scrolls to the left; if the current direction is right-to-left, the display scrolls to the right. This has the effect of outputting each new character to the same location on the LCD.

The following example sketch enables automatic scrolling and prints the character 0 to 9 at the position (16,0) of the LCD. Change this to (20,0) for a 20×4 LCD.

With the function createChar() it is possible to create and display custom characters on the LCD. This is especially useful if you want to display a character that is not part of the standard ASCII character set.

Technical info: LCDs that are based on the Hitachi HD44780 LCD controller have two types of memories: CGROM and CGRAM (Character Generator ROM and RAM). CGROM generates all the 5 x 8 dot character patterns from the standard 8-bit character codes. CGRAM can generate user-defined character patterns.

/* Example sketch to create and display custom characters on character LCD with Arduino and LiquidCrystal library. For more info see www.www.makerguides.com */

After including the library and creating the LCD object, the custom character arrays are defined. Each array consists of 8 bytes, 1 byte for each row. In this example 8 custom characters are created.

In this article I have shown you how to use an alphanumeric LCD with Arduino. I hope you found it useful and informative. If you did, please share it with a friend that also likes electronics and making things!

I would love to know what projects you plan on building (or have already built) with these LCDs. If you have any questions, suggestions, or if you think that things are missing in this tutorial, please leave a comment down below.

If you’ve ever tried to connect an LCD display to an Arduino, you might have noticed that it consumes a lot of pins on the Arduino. Even in 4-bit mode, the Arduino still requires a total of seven connections – which is half of the Arduino’s available digital I/O pins.

The solution is to use an I2C LCD display. It consumes only two I/O pins that are not even part of the set of digital I/O pins and can be shared with other I2C devices as well.

True to their name, these LCDs are ideal for displaying only text/characters. A 16×2 character LCD, for example, has an LED backlight and can display 32 ASCII characters in two rows of 16 characters each.

If you look closely you can see tiny rectangles for each character on the display and the pixels that make up a character. Each of these rectangles is a grid of 5×8 pixels.

At the heart of the adapter is an 8-bit I/O expander chip – PCF8574. This chip converts the I2C data from an Arduino into the parallel data required for an LCD display.

If you are using multiple devices on the same I2C bus, you may need to set a different I2C address for the LCD adapter so that it does not conflict with another I2C device.

An important point here is that several companies manufacture the same PCF8574 chip, Texas Instruments and NXP Semiconductors, to name a few. And the I2C address of your LCD depends on the chip manufacturer.

So your LCD probably has a default I2C address 0x27Hex or 0x3FHex. However it is recommended that you find out the actual I2C address of the LCD before using it.

Connecting an I2C LCD is much easier than connecting a standard LCD. You only need to connect 4 pins instead of 12. Start by connecting the VCC pin to the 5V output on the Arduino and GND to ground.

Now we are left with the pins which are used for I2C communication. Note that each Arduino board has different I2C pins that must be connected accordingly. On Arduino boards with the R3 layout, the SDA (data line) and SCL (clock line) are on the pin headers close to the AREF pin. They are also known as A5 (SCL) and A4 (SDA).

After wiring up the LCD you’ll need to adjust the contrast of the display. On the I2C module you will find a potentiometer that you can rotate with a small screwdriver.

Plug in the Arduino’s USB connector to power the LCD. You will see the backlight lit up. Now as you turn the knob on the potentiometer, you will start to see the first row of rectangles. If that happens, Congratulations! Your LCD is working fine.

To drive an I2C LCD you must first install a library called LiquidCrystal_I2C. This library is an enhanced version of the LiquidCrystal library that comes with your Arduino IDE.

The I2C address of your LCD depends on the manufacturer, as mentioned earlier. If your LCD has a Texas Instruments’ PCF8574 chip, its default I2C address is 0x27Hex. If your LCD has NXP Semiconductors’ PCF8574 chip, its default I2C address is 0x3FHex.

So your LCD probably has I2C address 0x27Hex or 0x3FHex. However it is recommended that you find out the actual I2C address of the LCD before using it. Luckily there’s an easy way to do this, thanks to the Nick Gammon.

But, before you proceed to upload the sketch, you need to make a small change to make it work for you. You must pass the I2C address of your LCD and the dimensions of the display to the constructor of the LiquidCrystal_I2C class. If you are using a 16×2 character LCD, pass the 16 and 2; If you’re using a 20×4 LCD, pass 20 and 4. You got the point!

First of all an object of LiquidCrystal_I2C class is created. This object takes three parameters LiquidCrystal_I2C(address, columns, rows). This is where you need to enter the address you found earlier, and the dimensions of the display.

In ‘setup’ we call three functions. The first function is init(). It initializes the LCD object. The second function is clear(). This clears the LCD screen and moves the cursor to the top left corner. And third, the backlight() function turns on the LCD backlight.

After that we set the cursor position to the third column of the first row by calling the function lcd.setCursor(2, 0). The cursor position specifies the location where you want the new text to be displayed on the LCD. The upper left corner is assumed to be col=0, row=0.

There are some useful functions you can use with LiquidCrystal_I2C objects. Some of them are listed below:lcd.home() function is used to position the cursor in the upper-left of the LCD without clearing the display.

lcd.scrollDisplayRight() function scrolls the contents of the display one space to the right. If you want the text to scroll continuously, you have to use this function inside a for loop.

lcd.scrollDisplayLeft() function scrolls the contents of the display one space to the left. Similar to above function, use this inside a for loop for continuous scrolling.

If you find the characters on the display dull and boring, you can create your own custom characters (glyphs) and symbols for your LCD. They are extremely useful when you want to display a character that is not part of the standard ASCII character set.

CGROM is used to store all permanent fonts that are displayed using their ASCII codes. For example, if we send 0x41 to the LCD, the letter ‘A’ will be printed on the display.

CGRAM is another memory used to store user defined characters. This RAM is limited to 64 bytes. For a 5×8 pixel based LCD, only 8 user-defined characters can be stored in CGRAM. And for 5×10 pixel based LCD only 4 user-defined characters can be stored.

Creating custom characters has never been easier! We have created a small application called Custom Character Generator. Can you see the blue grid below? You can click on any 5×8 pixel to set/clear that particular pixel. And as you click, the code for the character is generated next to the grid. This code can be used directly in your Arduino sketch.

After the library is included and the LCD object is created, custom character arrays are defined. The array consists of 8 bytes, each byte representing a row of a 5×8 LED matrix. In this sketch, eight custom characters have been created.

Adding a display to your Arduino can serve many purposes. Since a common use for microcontrollers is reading data from sensors, a display allows you to see this data in real-time without needing to use the serial monitor within the Arduino IDE. It also allows you to give your projects a personal touch with text, images, or even interactivity through a touch screen.

Transparent Organic Light Emitting Diode (TOLED) is a type of LED that, as you can guess, has a transparent screen. It builds on the now common OLED screens found in smartphones and TVs, but with a transparent display, offers up some new possibilities for Arduino screens.

Take for example this brilliant project that makes use of TOLED displays. By stacking 10 transparent OLED screens in parallel, creator Sean Hodgins has converted a handful of 2D screens into a solid-state volumetric display. This kind of display creates an image that has 3-dimensional depth, taking us one step closer to the neon, holographic screens we imagine in the future.

Crystalfontz has a tiny monochrome (light blue) 1.51" TOLED that has 128x56 pixels. As the technology is more recent than the following displays in this list, the cost is higher too. One of these screens can be purchased for around $26, but for certain applications, it might just be worth it.

The liquid crystal display (LCD) is the most common display to find in DIY projects and home appliances alike. This is no surprise as they are simple to operate, low-powered, and incredibly cheap.

This type of display can vary in design. Some are larger, with more character spaces and rows; some come with a backlight. Most attach directly to the board through 8 or 12 connections to the Arduino pins, making them incompatible with boards with fewer pins available. In this instance, buy a screen with an I2C adapter, allowing control using only four pins.

Available for only a few dollars (or as little as a couple of dollars on AliExpress with included I2C adapter), these simple displays can be used to give real-time feedback to any project.

The screens are capable of a large variety of preset characters which cover most use cases in a variety of languages. You can control your LCD using the Liquid Crystal Library provided by Arduino. The display() and noDisplay() methods write to the LCD, as shown in the official tutorial on the Arduino website.

Are you looking for something simple to display numbers and a few basic characters? Maybe you are looking for something with that old-school arcade feel? A seven-segment display might suit your needs.

These simple boards are made up of 7 LEDs (8 if you include the dot), and work much like normal LEDs with a common Anode or Cathode connection. This allows them to take one connection to V+ (or GND for common cathode) and be controlled from the pins of your Arduino. By combining these pins in code, you can create numbers and several letters, along with more abstract designs—anything you can dream up using the segments available!

Next on our list is the 5110 display, also affectionately known as the Nokia display due to its wide use in the beloved and nigh indestructible Nokia 3310.

These tiny LCD screens are monochrome and have a screen size of 84 x 48 pixels, but don"t let that fool you. Coming in at around $2 on AliExpress, these displays are incredibly cheap and usually come with a backlight as standard.

Depending on which library you use, the screen can display multiple lines of text in various fonts. It"s also capable of displaying images, and there is free software designed to help get your creations on screen. While the refresh rate is too slow for detailed animations, these screens are hardy enough to be included in long-term, always-on projects.

For a step up in resolution and functionality, an OLED display might be what you are looking for. At first glance, these screens look similar to the 5110 screens, but they are a significant upgrade. The standard 0.96" screens are 128 x 64 monochrome, and come with a backlight as standard.

They connect to your Arduino using I2C, meaning that alongside the V+ and GND pins, only two further pins are required to communicate with the screen. With various sizes and full color options available, these displays are incredibly versatile.

For a project to get you started with OLED displays, our Electronic D20 build will teach you everything you need to know -- and you"ll end up with the ultimate geeky digital dice for your gaming sessions!

These displays can be used in the same way as the others we have mentioned so far, but their refresh rate allows for much more ambitious projects. The basic monochrome screen is available on Amazon.

Thin-film-transistor liquid-crystal displays (TFT LCDs) are in many ways another step up in quality when it comes to options for adding a screen to your Arduino. Available with or without touchscreen functionality, they also add the ability to load bitmap files from an on-board microSD card slot.

Arduino have an official guide for setting up their non-touchscreen TFT LCD screen. For a video tutorial teaching you the basics of setting up the touchscreen version, YouTuber educ8s.tv has you covered:

With the touchscreen editions of these screens costing less than $10 on AliExpress, these displays are another great choice for when you need a nice-looking display for your project.

Looking for something a little different? An E-paper (or E-ink depending on who you ask) display might be right for you. These screens differ from the others giving a much more natural reading experience, it is no surprise that this technology is the cornerstone of almost every e-reader available.

The reason these displays look so good is down to the way they function. Each "pixel" contains charged particles between two electrodes. By switching the charge of each electrode, you can influence the negatively charged black particles to swap places with the positively charged white particles.

This is what gives e-paper such a natural feel. As a bonus, once the ink is moved to its location, it uses no power to keep it there. This makes these displays naturally low-power to operate.

This article has covered most options available for Arduino displays, though there are definitely more weird and wonderful ways to add feedback to your DIY devices.

Now that you have an idea of what is out there, why not incorporate a screen into your DIY smart home setup? If retro gaming is more your thing, why not create some retro games on Arduino?

The Arduino family of devices is features rich and offers many capabilities. The ability to interface to external devices readily is very enticing, although the Arduino has a limited number of input/output options. Adding an external display would typically require several of the limited I/O pins. Using an I2C interface, only two connections for an LCD character display are possible with stunning professional results. We offer both a 4 x 20 LCD.

The character LCD is ideal for displaying text and numbers and special characters. LCDs incorporate a small add-on circuit (backpack) mounted on the back of the LCD module. The module features a controller chip handling I2C communications and an adjustable potentiometer for changing the intensity of the LED backlight. An I2C LCD advantage is that wiring is straightforward, requiring only two data pins to control the LCD.

A standard LCD requires over ten connections, which can be a problem if your Arduino does not have many GPIO pins available. If you happen to have an LCD without an I2C interface incorporated into the design, these can be easily

The LCD displays each character through a matrix grid of 5×8 pixels. These pixels can display standard text, numbers, or special characters and can also be programmed to display custom characters easily.

Connecting the Arduino UNO to the I2C interface of the LCD requires only four connections. The connections include two for power and two for data. The chart below shows the connections needed.

The I2C LCD interface is compatible across much of the Arduino family. The pin functions remain the same, but the labeling of those pins might be different.

Located on the back of the LCD screen is the I2C interface board, and on the interface is an adjustable potentiometer. This adjustment is made with a small screwdriver. You will adjust the potentiometer until a series of rectangles appear – this will allow you to see your programming results.

The Arduino module and editor do not know how to communicate with the I2C interface on the LCD. The parameter to enable the Arduino to send commands to the LCD are in separately downloaded LiquidCrystal_I2C library.

Before installing LiquidCrystal_I2C, remove any other libraries that may reside in the Arduino IDE with the same LiquidCrystal_I2C name. Doing this will ensure that only the known good library is in use. LiquidCrystal_I2C works in combination with the preinstalled Wire.h library in the Arduino editor.

To install the LiquidCrystal_I2C library, use the SketchSketch > Include Library > Add .ZIP Library…from the Arduino IDE (see example). Point to the LiquidCrystal_I2C-master.zip which you previously downloaded and the Library will be installed and set up for use.

Several examples and code are included in the Library installation, which can provide some reference and programming examples. You can use these example sketches as a basis for developing your own code for the LCD display module.

There may be situations where you should uninstall the Arduino IDE. The reason for this could be due to Library conflicts or other configuration issues. There are a few simple steps to uninstalling the IDE.

The I2c address can be changed by shorting the address solder pads on the I2C module. You will need to know the actual address of the LCD before you can start using it.

Once you have the LCD connected and have determined the I2C address, you can proceed to write code to display on the screen. The code segment below is a complete sketch ready for downloading to your Arduino.

The code assumes the I2C address of the LCD screen is at 0x27 and can be adjusted on the LiquidCrystal_I2C lcd = LiquidCrystal_I2C(0x27,16,2); as required.

Similar to the cursor() function, this will create a block-style cursor. Displayed at the position of the next character to be printed and displays as a blinking rectangle.

This function turns off any characters displayed to the LCD. The text will not be cleared from the LCD memory; rather, it is turned off. The LCD will show the screen again when display() is executed.

Scrolling text if you want to print more than 16 or 20 characters in one line then the scrolling text function is convenient. First, the substring with the maximum of characters per line is printed, moving the start column from right to left on the LCD screen. Then the first character is dropped, and the next character is displayed to the substring. This process repeats until the full string has been displayed on the screen.

The LCD driver backpack has an exciting additional feature allowing you to create custom characters (glyph) for use on the screen. Your custom characters work with both the 16×2 and 20×4 LCD units.

A custom character allows you to display any pattern of dots on a 5×8 matrix which makes up each character. You have full control of the design to be displayed.

To aid in creating your custom characters, there are a number of useful tools available on Internet. Here is a LCD Custom Character Generator which we have used.

We realize a change is not always welcomed but we feel it"s the best way to move forward. The new Workshop4 IDE supports 4 development environments, to cater for different user requirements and skill levels and the Serial environment you"ve mentioned is one of them. The Serial environment is basically a 4DGL application that uses a very simple protocol and makes the display act as a slave and it works well when the host and the display are in close proximity, i.e. both on the same application PCB or the distance of the host is within a foot or two from the display. In most cases this works real well as long as the transmission path is free of external noise. There are many high end commercial products designed by many thousands of customers using just the serial platform. If the environment is noisy or the distance between the display and the host is far apart, then why not use the Designer environment and roll out your own top notch serial protocol with many different levels of error checking? Many customers also employ this method. A good outcome for any application always starts by proper understanding of what"s required and a good feasibility study of all the factors involved. You mention you"ve used many of our displays (thank you for your support), but have you tried seeking help from our very helpful team of tech support engineers? If not, please do so, I"m sure you"ll find they"ll be able to resolve most of your problems.

Edit: I have just been informed that a user reported a crashing problem on Friday the 22nd of February, he was supplied with a Fix on Saturday the 23rd and Workshop was shipping with the fix integrated on Monday the 25th. If you are that user we apologize for any inconvenience. This problem was only limited to the Goldelox based displays and not on the Picaso.

To establish a good communication between human world and machine world, display units play an important role. And so they are an important part of embedded systems. Display units - big or small, work on the same basic principle. Besides complex display units like graphic displays and 3D dispays, one must know working with simple displays like 16x1 and 16x2 units. The 16x1 display unit will have 16 characters and are in one line. The 16x2 LCD will have 32 characters in total 16in 1st line and another 16 in 2nd line. Here one must understand that in each character there are 5x10=50 pixels so to display one character all 50 pixels must work together. But we need not to worry about that because there is another controller (HD44780) in the display unit which does the job of controlling the pixels. (you can see it in LCD unit, it is the black eye at the back ).

In this tutorial, we are going to interface a 16x2 LCD with ARDUINO UNO. Unlike normal development boards interfacing an LCD to an ARDUINO is quite easy. Here we don’t have to worry about data sending and receiving. We just have to define the pin numbers and it will be ready to display data on LCD.

Note:We updated this tutorial and added some more additional information along with a step-by-step guide to interface 16x2 LCD withArduino. You can follow the below link for an updated tutorial.

In 16x2 LCD there are 16 pins over all if there is a back light, if there is no back light there will be 14 pins. One can power or leave the back light pins. Now in the 14 pins there are 8 data pins (7-14 or D0-D7), 2 power supply pins (1&2 or VSS&VDD or GND&+5v), 3rd pin for contrast control (VEE-controls how thick the characters should be shown), and 3 control pins (RS&RW&E).

In the circuit, you can observe I have only took two control pins, this gives the flexibility. The contrast bit and READ/WRITE are not often used so they can be shorted to ground. This puts LCD in highest contrast and read mode. We just need to control ENABLE and RS pins to send characters and data accordingly.

The ARDUINO IDE allows the user to use LCD in 4 bit mode. This type of communication enables the user to decrease the pin usage on ARDUINO, unlike other the ARDUINO need not to be programmed separately for using it in 4 it mode because by default the ARDUINO is set up to communicate in 4 bit mode. In the circuit you can see we have used 4bit communication (D4-D7).

First we need to enable the header file (‘#include ’), this header file has instructions written in it, which enables the user to interface an LCD to UNO in 4 bit mode without any fuzz. With this header file we need not have to send data to LCD bit by bit, this will all be taken care of and we don’t have to write a program for sending data or a command to LCD bit by bit.

Second we need to tell the board which type of LCD we are using here. Since we have so many different types of LCD (like 20x4, 16x2, 16x1 etc.). Here we are going to interface a 16x2 LCD to the UNO so we get ‘lcd.begin(16, 2);’. For 16x1 we get ‘lcd.begin(16, 1);’.

In this instruction we are going to tell the board where we connected the pins. The pins which are connected need to be represented in order as “RS, En, D4, D5, D6, D7”. These pins are to be represented correctly. Since we have connected  RS to PIN0 and so on as show in the circuit diagram, we represent the pin number to board as “LiquidCrystal lcd(0, 1, 8, 9, 10, 11);”. The data which needs to be displayed in LCD should be written as “ cd.print("hello, world!");”. With this command the LCD displays ‘hello, world!’.

As you can see we need not to worry about any thing else, we just have to initialize and the UNO will be ready to display data. We don’t have to write a program loop to send the data BYTE by BYTE here.

An LCD (Liquid Crystal Display) is a great way to display information in our Arduino Uno controller. We will be wiring and programming an alphanumeric, two rows with 16 characters on each row. The display has an LED (Light Emitting Diode) backlight with adjustable contrast.

This white and blue LCD will display “Hello World!” on the top line and temperature on the bottom line. The thermistor temperature circuit created last time will be displayed in both Celsius and Fahrenheit degrees. Let’s get started.

When you look at an LCD display, it is made up of a series of dots or pixels. Each of these pixels is a liquid crystal. If electricity flows through the liquid crystal it will change its structure and be more rigid. This rigidity will look darker than if no electricity is applied. If we use a light behind this LCD then the backlight will make the pixels more pronounced. So electricity on the pixel will block the light and no electricity will allow the light through. This contrast is what we see using an LCD display.

The LiquidCrystal.zip file came on the disk with the Arduino UNO R3 super starter kit. It can also be downloaded from the link below with the program. Select this library and then select open. This will add the library to the Arduino IDE (Integrated Development Environment).

This first part will set up the library and declare the variables for the LCD display unit. Using the Steinhart-Hart Equation we declare our variables and set the coefficients for the equation.

The LCD is set up with 16 characters and 2 lines. The cursor for the LCD display is set for the first character on the first line by default. We then print the message “ Hello, World!”.

The program will calculate the temperature in Celsius (T) and in Fahrenheit (TF). The LCD cursor is then set to the second row and column 0. We can then print our temperatures and units of measure.

You will see the ‘Hello World!’ and the current temperature in two units of measure displayed on the LCD. Hold the thermistor between your fingers to see how rapidly the temperature can be read.