arduino i2c lcd display tutorial in stock

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.

According to the Texas Instruments’ datasheet, the three address selection bits (A0, A1 and A2) are placed at the end of the 7-bit I2C address register.

According to the NXP Semiconductors’ datasheet, the three address selection bits (A0, A1 and A2) are also placed at the end of the 7-bit I2C address register. But the other bits in the address register are different.

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.

Filter your search by typing ‘liquidcrystal‘. There should be some entries. Look for the LiquidCrystal I2C library by Frank de Brabander. Click on that entry, and then select Install.

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.

As discussed earlier in this tutorial a character is made up of a 5×8 pixel matrix, so you need to define your custom character within that matrix. You can use the createChar() function to define a character.

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.

This article includes everything you need to know about using acharacter I2C LCD with Arduino. I have included a wiring diagram and many example codes to help you get started.

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_I2C library.

Once you know how to display text and numbers on the LCD, I suggest you take a look at the articles below. In these tutorials, you will learn how to measure and display sensor data on the LCD.

Each rectangle is made up of a grid of 5×8 pixels. Later in this tutorial, I will show you how you can control the individual pixels to display custom characters on the LCD.

They all use the same HD44780 Hitachi LCD controller, so you can easily swap them. You will only need to change the size specifications in your Arduino code.

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

Note that an Arduino Uno with the R3 layout (1.0 pinout) also has the SDA (data line) and SCL (clock line) pin headers close to the AREF pin. Check the table below for more details.

After you have wired up the LCD, you will need to adjust the contrast of the display. On the I2C module, you will find a potentiometer that you can turn with a small screwdriver.

The LiquidCrystal_I2C library works in combination with the Wire.h library which allows you to communicate with I2C devices. This library comes pre-installed with the Arduino IDE.

To install this library, go to Tools > Manage Libraries (Ctrl + Shift + I on Windows) in the Arduino IDE. The Library Manager will open and update the list of installed libraries.

*When using the latest version of the LiquidCrystal_I2C library it is no longer needed to include the wire.h library in your sketch. The other library imports wire.h automatically.

Note that counting starts at 0 and the first argument specifies the column. So lcd.setCursor(2,1) sets the cursor on the third column and the second row.

Next the string ‘Hello World!’ is printed with lcd.print("Hello World!"). Note that you need to place quotation marks (” “) around the text since we are printing a text string.

The example sketch above shows you the basics of displaying text on the LCD. Now we will take a look at the other functions of the LiquidCrystal_I2C library.

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.

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.

In this Arduino LCD I2C tutorial, we will learn how to connect an LCD I2C (Liquid Crystal Display) to the Arduino board. LCDs are very popular and widely used in electronics projects for displaying information. There are many types of LCD. This tutorial takes LCD 16x2 (16 columns and 2 rows) as an example. The other LCDs are similar.

In the previous tutorial, we had learned how to use the normal LCD. However, wiring between Arduino and the normal LCD is complicated. Therefore, LCD I2C has been created to simplify the wiring. Actually, LCD I2C is composed of a normal LCD, an I2C module and a potentiometer.

We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.

lcd.print() function supports only ASCII characters. If you want to display a special character or symbol (e.g. heart, angry bird), you need to use the below character generator.

Depending on manufacturers, the I2C address of LCD may be different. Usually, the default I2C address of LCD is 0x27 or 0x3F. Try these values one by one. If you still failed, run the below code to find the I2C address.

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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.

The LiquidCrystal_I2C is available from GitHub. When visiting the GitHub page, select the Code button and from the drop-down menu, choose Download ZIP option to save the file to a convenient location on your workstation.

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.

The classic parallel LCD sometimes post a problem for projects that use a lot of Arduino pins. The least amount of pins you can use is six, excluding the power pins and the potentiometer contrast adjust (optional) pin. Thankfully, by using an I2C LCD "backpack", the pin use can be reduced to four!

At the center of the board is the PCF8547 controller by NXP. The row of pins is attached to the same row of pins on any HD44870-compatible LCD. The four pins on the side are the one you"ll attach to the Arduino or any I2C-supported microcontroller.

Some backpacks come with PCF8574T while some come with PCF8574AT. Each of this chips have their own I2C address! PCF84574T uses 0x27 while PCF8457AT uses 0x3F. These addresses are used in the sketch so they"re kinda important to know.

You can, in fact, change the I2C address via the I2C Address Set pads on the board.  A0, A1, A2 represent three bits that would be subtracted from the address. By default, each of these pads are connected to VDD or the positive supply. Soldering them connects them to GND. For example, if you were to solder pad A0, the address becomes 0x26 because 0x27 - (A2 + A1 - A0) = 0x27 - (001)2 = 0x26. If you were to solder A0 and A1 then the address becomes 0x24 because 0x27 - (A2 + A1 + A0) = 0x27 - (011)2 = 0x24.

For using with an Arduino, we"ll need the LiquidCrystal_I2C library. Here"s an example sketch which is found in File -> Examples -> LiquidCrystal_I2C -> HelloWorld:

The first parameter is the I2C address, the second is the number of columns and the last number is the number of rows. The library can be used with other LCD sizes as long as the controller is HD44870.

So far I"m really liking this I2C LCD backpack as it reduces the number of wires I have to use. If you"re also having problem with the pin count of a common parallel LCD, then you should try this one.

What is the purpose of declaring LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); if we are using pins A4 and A5? I know that 0x27 is the ic address but what is the rest for?

I am getting a error while i m going to add zip file of lcd library error id this zip file does not contains a valid library please help me to resolve this issue as soon as possible.....

Hey guys. My LCD works fine using the above instructions (when replacing the existing LCD library in the Arduino directory) but I can"t get the backlight to ever switch off. Suggestions?

In the previous Arduino LCD tutorial, you have noticed that the classic parallel LCD consumes a lot of pins on the Arduino. Even in the 4-bit mode, it requires at least 6 digital I/O pins on the Arduino. So in many projects where you use the classic parallel LCD, you will run out of pins very easily.

The solution to this problem is to use an I2C LCD display. It requires only two digital I/O pins and you can even share those two pins with other I2C devices.

Commonly available LCD displays with I2C LCD adapter are 16×2 and 20×4 character LCD displays. They both have a total of 16 pins including 8 parallel data pins. So if you don’t use an I2C LCD you will need at least 6 digital I/O pins on the Arduino to display something.

If you look closely you will find that the characters of the LCD are built using a grid of 5×8 pixels. Later in this tutorial, you will learn how to turn on and off any individual pixels to make custom characters.

At the center of this adapter, there is an 8-bit I/O expander chip – PCF8574. It takes the I2C data from the MCU (Arduino) and converts it into serial data required for an LCD display. At one side the I2C LCD adapter has four pins that can be connected to Arduino or any microcontroller that supports the I2C communication protocol. On another side, it has 16 pins that are connected to the LCD display.

There are two header pins to control the backlight of the LCD display. One pin supplies a 5v power and another pin is for the backlight LED. These two pins are connected together by default. So the backlight will be always on. You can remove the jumper to turn off the backlight LED or you can use a potentiometer in between these two pins to control the intensity of the backlight LED.

Some I2C LCD adapters come with PCF8574, while others use PCF8574A chips. Each of these chips has its own I2C address. The PCF8574 chip from NXP Semiconductor uses 0x27 while the PCF8574A chip uses 0x3F.

Sometimes you need to change this default I2C address for a project where you use multiple I2C devices on the same I2C bus So that it does not conflict with other I2C devices.

If you go through the datasheet of PCF8574 by NXP, you will find that PCF8574 and PCF8574A use a 7-bit I2C address. The first four-bit is fixed and the last three-bit is hardware selectable.

Connect the LCD’s VCC pin to the Arduino 5v pin and the Ground pin to the Arduino Ground pin. The remaining two pins are SCL and SDA. You need to connect the SCL pin to the Arduino SCL pin and SDA to the Arduino SDA pin.

In this tutorial, I am using the LiquidCrystal-I2C library to control the display. It has many pre-built functions to control an I2C LCD display in a much simpler way.

To install the library first you need to download it from the LiquidCrystal-I2C GitHub repository. Then open your Arduino IDE and navigate to Sketch > Include Library > Add .ZIP Library.

You need to know the I2C address of the LCD before starting the communication. To know the I2C address of your LCD run the below sketch.#include

Printing text on the LCD is very simple. The below sketch will print some text on the display. But before uploading this sketch you need to do some minor changes according to your display size and address.

In the second line, I create a LiquidCrystal_I2C variable. It requires three variables – the I2C address of the LCD and the dimension of the LCD (columns and rows of the display). The I2C address of my display is 0x27 and it has 16 columns and 2 rows. So I will use – LiquidCrystal_I2C lcd(0x27,16,2). If you have a different LCD display change the I2C address and dimension accordingly.

Then you need to define a LiquidCrystal_I2C variable for your LCD. It requires three variables – the I2C address of the LCD and the dimension of the LCD (columns and rows of the display).

Then in the setup section, you have to initialize the display using the init() function. The clear() function will clear the display buffer. It is good to clear the display buffer before printing anything on the display so that it does not display anything that was previously stored in the display buffer.

clear() – Clears the display and places the cursor at the top left corner. You can use this function to display different text/strings at the same place at a time. The below code shows the use of this function.#include

noDisplay() – Turns off the LCD screen but does not clear data from the LCD memory. The below code shows the use of display() and noDisplay() function.#include

write() – This function is used to write a character to the display. You can see the use of this function in the I2C LCD custom character section below.

scrollDisplayRight() – Moves the display content one step to the right. The below code shows the use of these functions.#include

rightToLeft() – sets the display orientation from right to left. That means the text/strings will flow from right to left. The below code shows the use of this function.#include

As you see in the above section the character in a Liquid crystal display is built using a grid of 5×8 small pixels. You can individually turn on and off any pixel and make your own custom character. The custom character data is stored in the CGRAM of the display.

Displays that use the Hitachi HD44780 controller have two types of memories – CGROM and CGRAM (Character Generator ROM & RAM). CGROM is non-volatile means it can’t be modified whereas CGRAM is volatile so it can be modified at any time.

CGROM stored all permanent fonts that can be displayed by using their ASCII code. For example, the character ‘A’ can be written using write(65) or write(0x41).

CGRAM is used for storing user-defined characters. The Hitachi HD44780 controller has a CGROM of 64 bytes. So for a 5×8 pixel-based LCD, up to 8 user-defined characters can be stored in the CGRAM. And for a 5×10 pixel-based LCD, only 4 user-defined characters can be stored.

There are some online and offline tools available to visually draw the custom character and it will automatically generate the byte code for you. I suggest you use the online LCD Character Creator tools.

Now in the below sketch, I will use that bite code to print the custom character on the LCD. Upload the below code to your Arduino board and see how the display looks like.

Here you can see that I include the LiquidCrystal_I2C library first. Then I create a LiquidCrystal_I2C variable for my LCD using the I2C address and dimension of my LCD. I am using an array smiley[] to store the bit data for the custom character.

The classic parallel LCD sometimes post a problem for projects that use a lot of Arduino pins. The least amount of pins you can use is six, excluding the power pins and the potentiometer contrast adjust (optional) pin. Thankfully, by using an I2C LCD "backpack", the pin use can be reduced to four!

At the center of the board is the PCF8547 controller by NXP. The row of pins is attached to the same row of pins on any HD44870-compatible LCD. The four pins on the side are the one you"ll attach to the Arduino or any I2C-supported microcontroller.

Some backpacks come with PCF8574T while some come with PCF8574AT. Each of this chips have their own I2C address! PCF84574T uses 0x27 while PCF8457AT uses 0x3F. These addresses are used in the sketch so they"re kinda important to know.

You can, in fact, change the I2C address via the I2C Address Set pads on the board.  A0, A1, A2 represent three bits that would be subtracted from the address. By default, each of these pads are connected to VDD or the positive supply. Soldering them connects them to GND. For example, if you were to solder pad A0, the address becomes 0x26 because 0x27 - (A2 + A1 - A0) = 0x27 - (001)2 = 0x26. If you were to solder A0 and A1 then the address becomes 0x24 because 0x27 - (A2 + A1 + A0) = 0x27 - (011)2 = 0x24.

For using with an Arduino, we"ll need the LiquidCrystal_I2C library. Here"s an example sketch which is found in File -> Examples -> LiquidCrystal_I2C -> HelloWorld:

The first parameter is the I2C address, the second is the number of columns and the last number is the number of rows. The library can be used with other LCD sizes as long as the controller is HD44870.

So far I"m really liking this I2C LCD backpack as it reduces the number of wires I have to use. If you"re also having problem with the pin count of a common parallel LCD, then you should try this one.

In the previous Arduino LCD tutorial, you have noticed that the classic parallel LCD consumes a lot of pins on the Arduino. Even in the 4-bit mode, it requires at least 6 digital I/O pins on the Arduino. So in many projects where you use the classic parallel LCD, you will run out of pins very easily.

The solution to this problem is to use an I2C LCD display. It requires only two digital I/O pins and you can even share those two pins with other I2C devices.

Commonly available LCD displays with I2C LCD adapter are 16×2 and 20×4 character LCD displays. They both have a total of 16 pins including 8 parallel data pins. So if you don’t use an I2C LCD you will need at least 6 digital I/O pins on the Arduino to display something.

If you look closely you will find that the characters of the LCD are built using a grid of 5×8 pixels. Later in this tutorial, you will learn how to turn on and off any individual pixels to make custom characters.

At the center of this adapter, there is an 8-bit I/O expander chip – PCF8574. It takes the I2C data from the MCU (Arduino) and converts it into serial data required for an LCD display. At one side the I2C LCD adapter has four pins that can be connected to Arduino or any microcontroller that supports the I2C communication protocol. On another side, it has 16 pins that are connected to the LCD display.

There are two header pins to control the backlight of the LCD display. One pin supplies a 5v power and another pin is for the backlight LED. These two pins are connected together by default. So the backlight will be always on. You can remove the jumper to turn off the backlight LED or you can use a potentiometer in between these two pins to control the intensity of the backlight LED.

Some I2C LCD adapters come with PCF8574, while others use PCF8574A chips. Each of these chips has its own I2C address. The PCF8574 chip from NXP Semiconductor uses 0x27 while the PCF8574A chip uses 0x3F.

Sometimes you need to change this default I2C address for a project where you use multiple I2C devices on the same I2C bus So that it does not conflict with other I2C devices.

If you go through the datasheet of PCF8574 by NXP, you will find that PCF8574 and PCF8574A use a 7-bit I2C address. The first four-bit is fixed and the last three-bit is hardware selectable.

Connect the LCD’s VCC pin to the Arduino 5v pin and the Ground pin to the Arduino Ground pin. The remaining two pins are SCL and SDA. You need to connect the SCL pin to the Arduino SCL pin and SDA to the Arduino SDA pin.

In this tutorial, I am using the LiquidCrystal-I2C library to control the display. It has many pre-built functions to control an I2C LCD display in a much simpler way.

To install the library first you need to download it from the LiquidCrystal-I2C GitHub repository. Then open your Arduino IDE and navigate to Sketch > Include Library > Add .ZIP Library.

You need to know the I2C address of the LCD before starting the communication. To know the I2C address of your LCD run the below sketch.#include

Printing text on the LCD is very simple. The below sketch will print some text on the display. But before uploading this sketch you need to do some minor changes according to your display size and address.

In the second line, I create a LiquidCrystal_I2C variable. It requires three variables – the I2C address of the LCD and the dimension of the LCD (columns and rows of the display). The I2C address of my display is 0x27 and it has 16 columns and 2 rows. So I will use – LiquidCrystal_I2C lcd(0x27,16,2). If you have a different LCD display change the I2C address and dimension accordingly.

Then you need to define a LiquidCrystal_I2C variable for your LCD. It requires three variables – the I2C address of the LCD and the dimension of the LCD (columns and rows of the display).

Then in the setup section, you have to initialize the display using the init() function. The clear() function will clear the display buffer. It is good to clear the display buffer before printing anything on the display so that it does not display anything that was previously stored in the display buffer.

clear() – Clears the display and places the cursor at the top left corner. You can use this function to display different text/strings at the same place at a time. The below code shows the use of this function.#include

noDisplay() – Turns off the LCD screen but does not clear data from the LCD memory. The below code shows the use of display() and noDisplay() function.#include

write() – This function is used to write a character to the display. You can see the use of this function in the I2C LCD custom character section below.

scrollDisplayRight() – Moves the display content one step to the right. The below code shows the use of these functions.#include

rightToLeft() – sets the display orientation from right to left. That means the text/strings will flow from right to left. The below code shows the use of this function.#include

As you see in the above section the character in a Liquid crystal display is built using a grid of 5×8 small pixels. You can individually turn on and off any pixel and make your own custom character. The custom character data is stored in the CGRAM of the display.

Displays that use the Hitachi HD44780 controller have two types of memories – CGROM and CGRAM (Character Generator ROM & RAM). CGROM is non-volatile means it can’t be modified whereas CGRAM is volatile so it can be modified at any time.

CGROM stored all permanent fonts that can be displayed by using their ASCII code. For example, the character ‘A’ can be written using write(65) or write(0x41).

CGRAM is used for storing user-defined characters. The Hitachi HD44780 controller has a CGROM of 64 bytes. So for a 5×8 pixel-based LCD, up to 8 user-defined characters can be stored in the CGRAM. And for a 5×10 pixel-based LCD, only 4 user-defined characters can be stored.

There are some online and offline tools available to visually draw the custom character and it will automatically generate the byte code for you. I suggest you use the online LCD Character Creator tools.

Now in the below sketch, I will use that bite code to print the custom character on the LCD. Upload the below code to your Arduino board and see how the display looks like.

Here you can see that I include the LiquidCrystal_I2C library first. Then I create a LiquidCrystal_I2C variable for my LCD using the I2C address and dimension of my LCD. I am using an array smiley[] to store the bit data for the custom character.

This tutorial shows how to use the I2C LCD (Liquid Crystal Display) with the ESP32 using Arduino IDE. We’ll show you how to wire the display, install the library and try sample code to write text on the LCD: static text, and scroll long messages. You can also use this guide with the ESP8266.

Additionally, it comes with a built-in potentiometer you can use to adjust the contrast between the background and the characters on the LCD. On a “regular” LCD you need to add a potentiometer to the circuit to adjust the contrast.

Before displaying text on the LCD, you need to find the LCD I2C address. With the LCD properly wired to the ESP32, upload the following I2C Scanner sketch.

After uploading the code, open the Serial Monitor at a baud rate of 115200. Press the ESP32 EN button. The I2C address should be displayed in the Serial Monitor.

Displaying static text on the LCD is very simple. All you have to do is select where you want the characters to be displayed on the screen, and then send the message to the display.

In this simple sketch we show you the most useful and important functions from the LiquidCrystal_I2C library. So, let’s take a quick look at how the code works.

The next two lines set the number of columns and rows of your LCD display. If you’re using a display with another size, you should modify those variables.

Then, you need to set the display address, the number of columns and number of rows. You should use the display address you’ve found in the previous step.

To display a message on the screen, first you need to set the cursor to where you want your message to be written. The following line sets the cursor to the first column, first row.

Scrolling text on the LCD is specially useful when you want to display messages longer than 16 characters. The library comes with built-in functions that allows you to scroll text. However, many people experience problems with those functions because:

The messageToScroll variable is displayed in the second row (1 corresponds to the second row), with a delay time of 250 ms (the GIF image is speed up 1.5x).

In a 16×2 LCD there are 32 blocks where you can display characters. Each block is made out of 5×8 tiny pixels. You can display custom characters by defining the state of each tiny pixel. For that, you can create a byte variable to hold  the state of each pixel.

In summary, in this tutorial we’ve shown you how to use an I2C LCD display with the ESP32/ESP8266 with Arduino IDE: how to display static text, scrolling text and custom characters. This tutorial also works with the Arduino board, you just need to change the pin assignment to use the Arduino I2C pins.

We hope you’ve found this tutorial useful. If you like ESP32 and you want to learn more, we recommend enrolling in Learn ESP32 with Arduino IDE course.

Hello friends welcome back to Techno-E-solution, In previous video we see how to interface LCD 16×2 to Arduino Uno, but there are very complicated circuits, so in this tutorial, I"ll show you how to reduce circuitry by using I2C module which is very compact & easy to connection. Simply connect I2C module with LCD parallel & connect I2C modules 4 pins to Arduino. I2C module has 4 output pins which contains VCC, GND, SDA, SCL where 5V supply gives to I2C module through VCC & GND to GND of Arduino. SDA is a data pin & SCL is clock pin of I2C module. To interface LCD and I2C with Arduino we need Liquid Crystal I2C Library in Arduino IDE software.

To make this project we need Arduino Liquidcrystal library in Arduino IDE. Follow following steps to add this library in Arduino IDE software.Open Arduino IDE Software.

Since the use of an LCD requires many microcontroller pins, we will reduce that number using serial communication, which is basically sending "packages" of data one after another, using only two pins of our microcontroller , pins SDA and SCL which are the analog pins A4 and A5 of the Arduino NANO or pro mini.

First of all we connect i2c pins module as shown in the schematic. Power the LCD module to 5 volts and connect the ground as well. The SDA pin of the i2c module conected to arduinio A5 and the SCL pin to A4. We connect the arduino to USB and we are ready to program. In order to make the LCD work we need to inport the LCD library for arduino.

In this tutorial, we will learn how to interface I2C LCD with Arduino and how to display static, scrolling, and custom characters on I2C LCD. This I2C LCD is a 16×2 device which means it can display 16 columns by two rows of characters. The characters are alphanumeric, but you can create custom characters for basic graphics, bar graphs that kind of thing. The LCD has the usual type of hd44780 controller, and it also has an I2C circuit connected with it which makes it easy to connect to the Arduino board. 16X2 LCD without I2C circuit has sixteen pins.

But if we want to connect this board directly with Arduino, we have to use at least eight pins of Arduino which will be a waste. So the better solution is to use an I2C LCD instead of typical 16×2 LCD. In this tutorial, we are using 16×2 I2C LCD, but LCD of any size will also work the same way as we will learn in this tutorial. The advantage of using an I2C LCD is that we only need to use four pins (including the VCC and GND pins) of Arduino to connect with this display.

At the backside of this liquid crystal display, you can also see a variable resistor. This variable resistor is used to modify the brightness of the LCD. This potentiometer is very handy when you are using this display module in different light conditions.

In this circuit, we are using the default I2C communication pins of Arduino UNO. In this board, A5 is the default SCL pin, and A4 is the default SDA pin for I2C communication. So you need to connect A5 with SCL pin of LCD and A4 with SDA pin of liquid crystal display. You can also check to this table for wiring connections.

We will introduce the library of I2C LCD in Arduino IDE. This library is not available in the compiler. So we need to install an external library. There are many I2C LCD libraries available. You can use different libraries if you want. But in this tutorial, we are using the library developed by johnrickman. Now add this library by following these steps:

When you connect your I2C display with Arduino, you need to check its address. Because every I2C device has an address associated with it. For many devices of I2C LCD, the default address is 0x27 where 0x shows hex format of the numbers. But address can be different in some cases. This address depends on the position of pads A0, A1, and A2 on the I2C controller on this device. As you can see, we have three soldering pads, so we can have 8 different values of address depending on the connections of the pads.

This code will search for devices connected with pins A4 and A5 and display its result on the serial monitor. After connecting the device with Arduino properly, you will get this message on the serial monitor. This message shows the address of liquid crystal display which is 0x27. You will most likely get the same address for LCD with 16 columns and 2 rows.

This code will display the message “Microcontrollers” in the first row and “I2C LCD tutorial” in the second row for one second. After that, it will clear the LCD and displays “Static text” in the first row and “I2C LCD tutorial” in the second row as shown below.

These two variables define the name of the total number of rows and columns of the display which in our case is 16×2. If you want to use a screen of any other size, you need to need to change the number here accordingly, for example, the 20×4 display.

This line is used to initialize the library with the address of LCD, the total number of columns and rows. The first argument to this function is an address which we have found in the last example. Second and thirds arguments are the size in terms of the number of columns and number of rows.

This backlight() function is used to turn on or turn off the backlight. Every LCD has a backlight built-in inside it, so you can control it through this function.

In loop() part, code is used to display messages and also to clear the message for LCD. To display anything text on LCD, first, you need to set the cursor position. Cursor position defines where you want to display the text. The setCursor()function is used to set the position. For example, if you want to set the cursor to the first row and first column, you will use this function like this:

First values inside this function define column number and second value defines row number. So inside the loop(), first we set the cursor to the first row and second column. After that lcd.print() will display the message “Microcontrollers” in the first row.

Similarly, these two lines will set the cursor to the second row and display the text “I2C LCD tutorial” on the second row. For one second same text will be displayed in the first and second row. The delay() is used to add the delay of one second.

To see the demonstration of this project, upload the code to the your board. But, before uploading code, make sure to select Arduino Unofrom Tools > Board and also select the correct COM port to which the board is connected fromTools > Port.

These two variables define the name of the total number of rows and columns of the display which in our case is 16×2. If you want to use the screen of any other size, you need to need to change the number here accordingly, for example, 20×4 display.

This line is used to initialize the library with the address of LCD, the total number of columns and rows. The first argument to this function is an address which we have found in the last example. Second and thirds arguments are the size in terms of the number of columns and number of rows.

The user defined scrollMessage() function will be used to scroll a text on the LCD. It takes in four arguments. The first is the row where we will display our message. The second is the message that will be displayed. The third is the delay time that will control the speed of the scrolling text. Lastly, the fourth argument is the total columns of the LCD.

This backlight() function is used to turn on or turn off the backlight. Every LCD has a backlight built-in inside it, so you can control it through this function.

In loop() part, we will first set the cursor and then print the static message by using lcd.print() and pass the staticMessage as an argyment inside it. Then call the scrollMessage() function and pass ‘1’ as the starting row, ‘scrollingMessage’ as the message to be displayed, 250ms delay time and specify the ‘totalColumns’ of the LCD.

To see the demonstration of this project, upload the code to the board. But, before uploading code, make sure to select Arduino Uno from Tools > Board and also select the correct COM port to which the board is connected from Tools > Port.

For our 16×2 LCD display that we are using, we have the option to display custom characters as well. In this particular LCD, each block consists of 5×8 pixels. These can be used to display custom characters by setting the state of each pixel by inside a byte variable.

There is a very simple way to generate the byte variable of your own custom character. Head over to the following custom character generator: (Custom Character Generator for HD44780 LCD Modules).

In our case, we will display a ‘+’ character on the screen. This is the byte variable that we will use in our program code to display this particular character on the LCD.

Inside the setup() function we will create the custom character by calling lcd.createChar() and pass a number between 0-7 (allocated location) and the byte variable as parameters inside it.

To see the demonstration of this project, upload the code to the board. But, before uploading code, make sure to select Arduino Unofrom Tools > Board and also select the correct COM port to which the board is connected fromTools > Port.

In our previous tutorial learned about SPI communication in Arduino. Today we will learn about another Serial Communication Protocol: I2C (Inter Integrated Circuits).Comparing I2C with SPI, I2C has only two wires while SPI uses four and I2C can have Multiple Master and Slave, while SPI can have only one master and multiple slaves. So there are more than one microcontroller in a project that need to be masters then I2C is used. I2C communication is generally used to communicate with Gyroscope, accelerometer, barometric pressure sensors, LED displays etc.

In this Arduino I2C tutorial we will use I2C communication between two arduino boards and send (0 to 127) values to each other by using potentiometer. Values will be displayed on the 16x2 LCD connected to each of the Arduino.  Here one Arduino will act as Master and another one will act as Slave. So let’s start with the introduction about I2C communication.

The term IIC stands for “Inter Integrated Circuits”. It is normally denoted as I2C or I squared C or even as 2-wire interface protocol (TWI) at some places but it all means the same. I2C is a synchronous communication protocol meaning, both the devices that are sharing the information must share a common clock signal. It has only two wires to share information out of which one is used for the cock signal and the other is used for sending and receiving data.

I2C communication was first introduced by Phillips. As said earlier it has two wires, these two wires will be connected across two devices. Here one device is called a masterand the other device is called as slave. Communication should and will always occur between two a Master and a Slave. The advantage of I2C communication is that more than one slave can be connected to a Master.

The voltage levels of I2C are not predefined. I2C communication is flexible, means the device which is powered by 5v volt, can use 5v for I2C and the 3.3v devices can use 3v for I2C communication. But what if two devices which are running on different voltages, need to communicate using I2C? A5V I2C bus can’t be connected with 3.3V device. In this case voltage shifters are used to match the voltage levels between two I2C buses.

I2C communication is used only for short distance communication. It is certainly reliable to an extent since it has a synchronised clock pulse to make it smart. This protocol is mainly used to communicate with sensor or other devices which has to send information to a master. It is very handy when a microcontroller has to communicate with many other slave modules using a minimum of only wires. If you are looking for a long range communication you should try RS232 and if you are looking for more reliable communication you should try the SPI protocol.

Use:This function is used to begin a transmission to the I2C device with the given slave address. Subsequently, build queue of bytes for transmission with the write() function and then transmit them by calling endTransmission() function. 7-bit address of the device is transmitted.

Here for demonstrating I2C communication in Arduino, we use Two Arduino UNO with Two 16X2 LCD display attached to each other and use two potentiometers at both arduino to determine the sending values (0 to 127) from master to slave and slave to master by varying the potentiometer.

We take input analog value at arduino pin A0 from (0 to 5V) by using potentiometer and convert them into Analog to Digital value (0 to 1023). Then these ADC values are further converted into (0 to 127) as we can send only 7-bit data through I2C communication. The I2C communication takes place through two wires at pin A4 & A5 of both arduino.

This tutorial has two programs one for master Arduino and other for slave Arduino. Complete programs for both the sides are given at the end of this project with a demonstration Video.

1. First of all we need to include the Wire library for using I2C communication functions and LCD library for using LCD functions. Also define LCD pins for 16x2 LCD. Learn more about interfacing LCD with Arduino here.

Next we initialize LCD display module in 16X2 mode and display the welcome message and clear after five seconds.lcd.begin(16,2); //Initilize LCD display

Next we display those received values from the slave arduino    with a delay of 500 microseconds and we continuously receive and display those value.lcd.setCursor(0,0); //Sets Currsor at line one of LCD

1. Same as master, first of all we need to include the Wire library for using I2C communication functions and LCD library for using LCD functions. Also define LCD pins for 16x2 LCD.

Next we initialize LCD display module in 16X2 mode and display the welcome message and clear after five seconds.lcd.begin(16,2); //Initilize LCD display

So this is how I2C communication takes place in Arduino, here we have use two Arduinos to demonstrate not only sending of data but also receiving the data using I2C communication. So now you can interface any I2C sensor to Arduino.