i2c 1602 serial lcd module library free sample

As we all know, though LCD and some other displays greatly enrich the man-machine interaction, they share a common weakness. When they are connected to a controller, multiple IOs will be occupied of the controller which has no so many outer ports. Also it restricts other functions of the controller. Therefore, LCD1602 with an I2C bus is developed to solve the problem.

I2C bus is a type of serial bus invented by PHLIPS. It is a high performance serial bus which has bus ruling and high or low speed device synchronization function required by multiple-host system. The blue potentiometer on the I2C LCD1602 (see the figure below) is used to adjust the backlight for better display. I²C uses only two bidirectional open-drain lines, Serial Data Line (SDA) and Serial Clock Line (SCL), pulled up with resistors. Typical voltages used are +5 V or +3.3 V although systems with other voltages are permitted.

Step 3:Since in some code, the libraries needed are not included in Arduino, so you need to add them before compiling. Unzip the downloaded file. Copy the folders under the Library folder to the libraries folder in Arduino (if you cannot find the path in Arduino, open Arduino IDE, click File ->Preferences, and you can see the path in the Browse box, as shown in the following diagram). Compile the program.

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.

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.

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.

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.

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:

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.

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.

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.

This is another great blue/yellow backlight LCD display. As the pin resources of Arduino controller is limited, your project may be not able to use normal LCD shield after connected with a certain quantity of sensors or SD card. However, with this I2C interface LCD module, you will be able to realize data display via only 2 wires. If you already has I2C devices in your project, this LCD module actually cost no more resources at all. It is fantastic for Arduino based project.

Here is pic shows how to connect an Arduino 1602 I2C module.The following is a table describing which pins on the Arduino should be connected to 1602 I2C LCD module.

I looked at a few libraries (Arduino ones) to get inspiration. In LCD_I2C_PCF8574.c I have added a lot of background and links to where you can get hold of other source, documentation and data on the PIC18F2685, I2C, the LCD and IO expander should you be so inclined. I also added a link to the library I ripped for the character generation. Thanks Mario. This file also contains details on how you may want to customise to your implementation, these are tagged with "TODO adapt" so you can use the MPLABX task list to grab them.

I took all my details/nomenclature etc. from an Hitachi hard copy LCD manual (yes hard copy, real paper an"all!) I obtained in the early 1980"s when we were still printing on flattened trees.

The code in main.c exercises all the functionality of the display including reading DD and CG ram and the busy flag. It should give a good heads up on how to use the library. I included a link to a YouTube Video so you can see it"s potential.

This module works with at least the LiquidCrystal I2C and LiquidCrystal_PCF8574 libraries available in the Arduino library manager. Address 0x3F worked for me since the A0, A1, and A2 jumpers are not shorted.

Google for LCM1602 and you will find many pages that mention the board - including the pinouts stated above and sample programs using the Arduino library.

Heres the scoop. The library that works with this chip set is available at this link. http://www.play-zone.ch/en/fileuploader/download/download/?d=0&file=custom%2Fupload%2FFile-1345667375.zip

On the software side, you have to download and install a new LiquidCrystal_I2C library for Arduino, which has the capability to talk to the LCD display over the I2C bus. Heres a link to the library. Follow the example code for the DFRobot board, which turns out to have the same configuration as this LCD, and it should fire right up for you. The LCD has white characters on a backlit blue background, and looked great.

The library allows to control I2C displays with functions extremely similar to LiquidCrystal library. THIS LIBRARY MIGHT NOT BE COMPATIBLE WITH EXISTING SKETCHES.

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.

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.

To install the library navigate to Sketch > Include Libraries > Manage Libraries… Wait for Library Manager to download the library index and update the list of installed libraries.

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.

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.

Your imagination is limitless. The only limitation is that the LiquidCrystal library only supports eight custom characters. But don’t be discouraged, look at the bright side, at least we have eight characters.

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.

In this tutorial, you’ll learn how to use ESP32 (or ESP8266) with the I2C LCD Display module (PCF8574) in Arduino IDE. We’ll be using the LiquidCrystal_I2C library with I2CWire.h library in Arduino Core to interface LCD 16×2 display via the I2C bus.

The library APIs are very similar to the standard LiquidCrystal library in Arduino that we’ve used in this previous tutorial. Except for the fact that it does use the I2C bus instead of parallel (4-Bit) data mode. Which does save a lot of GPIO pins and very suitable for many projects.

The I2C IO expander IC (PCF8574) is commonly used as a cheap solution to implement an I2C LCD interface that replaces the classic parallel connection to the LCDs (at least 6 pins) with an easy to use I2C bus (only 2 pins).

In this section, we’ll only discuss the important things in order to get started with these modules as quickly as possible and control them with ESP32 or ESP8266 boards.

The default address for the PCF8574 IC as stated in its datasheet is shown in the figure down below. It also shows you that 3 bits of the address are actually controllable by the user. You can solder these solder bridges to change the I2C address of the device.

As you know, the 3 non-fixed value bits in the address allow us to make 8 different combinations. And potentially be able to use up to 8 different I2C LCD devices on the same bus at the same time.

Here, I’ll solder the A0 bridge which forces the LSB in the address to become 0. Therefore, the I2C device address is now 0x26 instead of the default value 0x27.

Now, I’ve got 2 I2C LCD modules with 2 unique addresses (0x27, 0x26). And those are the two I’ll be using in LAB21 to show you how to use multiple I2C LCDs with ESP32 at the same time. All of this information does apply to any number of modules up to 8 on the same bus.

In this section, I’ll show you the library we’ll be using (LiquidCrystal_I2C), how to install it in Arduino IDE, how to make the ESP32 to I2C LCD module connections, and what are different API functions available to use in the library.

The library we’ll be using is called “LiquidCrysal_I2C”. It can be added manually by visiting GitHub and downloading the files to the Arduino directory. Or just by using the library manager within Arduino IDE itself, and this is what we’ll be doing hereafter.

And search for the LiquidCrystal I2C library and hit install. It’ll be automatically installed and added to your default Arduino libraries directory. If, for some reason, it didn’t complete properly. Then, you can try adding it manually after downloading it from GitHub.

The connection between ESP32 & I2C LCD module should be as follows. Note that the Wire library by default uses the I2C0 module & its default pins are GPIO21 & GPIO22, as we’ve stated in the previous I2C tutorial.

The code example down below does the following: We start with defining an object of LiquidCrystal_I2C, set its parameters, and initialize the LCD. Then, we’ll print “Hello World!” at the home position. Next, we’ll set the cursor to point at the 2nd row and print another string of text. And that’s all!

The LCD display’s controller (Hitachi HD44780) supports up to 8 custom characters that you can create and store on the LCD itself. Then you can send the Index of each custom character to be displayed later. Maybe 8 custom characters are not enough for your project, but it’s one little extra feature that you can occasionally use.

In this example, we’ll be defining two I2C LCD objects with similar parameters except for the address. The 1st LCD will be @ 0x26 and the 2nd one will be @ 0x27.

We’ll initialize both of them, and write a different message on each LCD to check that addressing is working as it should be. And that’s all about this LAB.

ESP32 I2C LCD module can be used in so many applications as we’ll see in future tutorials. I’ll keep updating this series of tutorials by adding more applications and techniques that may help you in your projects. Drop me a comment if you’ve got any questions or suggestions, I’ll be glad to help!