connecting an arduino to lcd module supplier

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If you’ve ever attempted to connect an LCD display to an Arduino, you’ve probably noticed that it uses a lot of Arduino pins. Even in 4-bit mode, the Arduino requires seven connections – half of the Arduino’s available digital I/O pins.

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

As the name suggests, these LCDs are ideal for displaying only characters. A 16×2 character LCD, for example, can display 32 ASCII characters across two rows.

If you look closely, you can see tiny rectangles for each character on the screen as well as 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.

There is a jumper on the board that provides power to the backlight. To control the intensity of the backlight, you can remove the jumper and apply external voltage to the header pin labeled ‘LED’.

If you have multiple devices on the same I2C bus, you may need to set a different I2C address for the LCD adapter to avoid conflicting with another I2C device.

For this purpose, the adapter comes with three solder jumpers/pads (A0, A1, and A2). The address is set when a jumper is shorted with a blob of solder.

An important point to note here is that several companies, including Texas Instruments and NXP Semiconductors, manufacture the same PCF8574 chip. 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 located at the end of the 7-bit I2C address register.

When you short a solder jumper, you pull that address input LOW. If you were to short all three jumpers, the address would be 0x20. So the range of all possible addresses spans from 0x20 to 0x27.

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

When you short a solder jumper, you pull that address input LOW. If you were to short all three jumpers, the address would be 0x38. So the range of all possible addresses spans from 0x38 to 0x3F.

So the I2C address of your LCD is most likely 0x27 or 0x3F. If you’re not sure what your LCD’s I2C address is, there’s an easy way to figure it out. You’ll learn about that later in this tutorial.

Now we are left with the pins that are used for I2C communication. Note that each Arduino board has different I2C pins that must be connected correctly. 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 referred to as A5 (SCL) and A4 (SDA).

After wiring the LCD, you will need to adjust the contrast of the LCD. On the I2C module, there is a potentiometer that can be rotated with a small screwdriver.

Now, turn on the Arduino. You will see the backlight light up. As you turn the potentiometer knob, the first row of rectangles will appear. If you have made it this far, Congratulations! Your LCD is functioning properly.

Before you can proceed, you must install the LiquidCrystal_I2C library. This library allows you to control I2C displays using functions that are very similar to the LiquidCrystal library.

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

Filter your search by entering ‘liquidcrystal‘. Look for the LiquidCrystal I2C library by Frank de Brabander. Click on that entry and then choose Install.

As previously stated, the I2C address of your LCD depends on the manufacturer. If your LCD has a PCF8574 chip from Texas Instruments, its I2C address is 0x27; if it has a PCF8574 chip from NXP Semiconductors, its I2C address is 0x3F.

If you’re not sure what your LCD’s I2C address is, you can run a simple I2C scanner sketch that scans your I2C bus and returns the address of each I2C device it finds.

However, before you upload the sketch, you must make a minor change to make it work for you. You must pass the I2C address of your LCD as well as the display dimensions to the LiquidCrystal_I2C constructor. If you’re using a 16×2 character LCD, pass 16 and 2; if you’re using a 20×4 character LCD, pass 20 and 4.

The next step is to create an object of LiquidCrystal_I2C class. The LiquidCrystal_I2C constructor accepts three inputs: I2C address, number of columns, and number of rows of the display.

In the setup, three functions are called. The first function is init(). It initializes the interface to the LCD. The second function is clear(). This function clears the LCD screen and positions the cursor in the upper-left corner. The third function, backlight(), turns on the LCD backlight.

The function setCursor(2, 0) is then called to move the cursor to the third column of the first row. The cursor position specifies where you want the new text to appear on the LCD. It is assumed that the upper left corner is col=0 and row=0.

There are many useful functions you can use with LiquidCrystal_I2C Object. Some of them are listed below:lcd.home() function positions 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 the above function, use this inside a for loop for continuous scrolling.

lcd.display() function turns on the LCD display, after it’s been turned off with noDisplay(). This will restore the text (and cursor) that was on the display.

If you find the default font uninteresting, you can create your own custom characters (glyphs) and symbols. They come in handy when you need to display a character that isn’t in the standard ASCII character set.

As previously discussed in this tutorial, a character is made up of a 5×8 pixel matrix; therefore, you must define your custom character within this matrix. You can define a character by using the createChar() function.

To use createChar(), you must first create an 8-byte array. Each byte in the array corresponds to a row in a 5×8 matrix. In a byte, the digits 0 and 1 indicate which pixels in a row should be OFF and which should be ON.

The CGROM stores the font that appears on a character LCD. When you instruct a character LCD to display the letter ‘A’, it needs to know which pixels to turn on so that we see an ‘A’. This data is stored in the CGROM.

CGRAM is an additional memory for storing user-defined characters. This RAM is limited to 64 bytes. Therefore, for a 5×8 pixel LCD, only 8 user-defined characters can be stored in CGRAM, whereas for a 5×10 pixel LCD, only 4 can be stored.

Creating custom characters has never been easier! We’ve developed a small application called Custom Character Generator. Can you see the blue grid below? You can click on any pixel to set or clear that 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.

There’s no limit to what you can create. The only limitation is that the LiquidCrystal_I2C library only supports eight custom characters. But don’t be sad, look at the bright side; at least we have eight characters.

After including the library and creating the LCD object, custom character arrays are defined. The array consists of 8 bytes, with each byte representing a row in a 5×8 matrix.

This sketch contains eight custom-characters. Take, for example, the Heart[8] array. You can see that the bits (0s and 1s) are forming the shape of a heart. 0 turns the pixel off, and 1 turns it on.

In the setup, we use the createChar() function to create a custom character. This function accepts two parameters: a number between 0 and 7 to reserve one of the eight supported custom characters, and the name of the array.

The Serial Monitor is a convenient way to view data from an Arduino, but what if you want to make your project portable and view sensor values without access to a computer? Liquid crystal displays (LCDs) are excellent for displaying a string of words or sensor data.

This guide will help you in getting your 16×2 character LCD up and running, as well as other character LCDs (such as 16×4, 16×1, 20×4, etc.) that use Hitachi’s LCD controller chip, the HD44780.

When activated by an electric current, these liquid crystals become opaque, blocking the backlight that is located behind the screen. As a result, that area will be darker than the rest. By activating the liquid crystal layer in specific pixels, characters can be generated.

As the name suggests, these LCDs are ideal for displaying only characters. A 16×2 character LCD, for example, can display 32 ASCII characters across two rows.

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

Character LCDs are available in a variety of sizes and colors, including 16×1, 16×4, 20×4, white text on a blue background, black text on a green background, and many more.

One advantage of using any of these displays in your project is that they are “swappable,” meaning that you can easily replace them with another LCD of a different size or color. Your code will need to be tweaked slightly, but the wiring will remain the same!

Before we get into the hookup and example code, let’s check out the pinout. A standard character LCD has 16 pins (except for an RGB LCD, which has 18 pins).

Vo (LCD Contrast) pin controls the contrast of the LCD. Using a simple voltage divider network and a potentiometer, we can make precise contrast adjustments.

RS (Register Select) pin is used to separate the commands (such as setting the cursor to a specific location, clearing the screen, etc.) from the data. The RS pin is set to LOW when sending commands to the LCD and HIGH when sending data.

R/W (Read/Write) pin allows you to read data from or write data to the LCD. Since the LCD is only used as an output device, this pin is typically held low. This forces the LCD into WRITE mode.

E (Enable) pin is used to enable the display. When this pin is set to LOW, the LCD ignores activity on the R/W, RS, and data bus lines; when it is set to HIGH, the LCD processes the incoming data.

D0-D7 (Data Bus) pins carry the 8 bit data we send to the display. To see an uppercase ‘A’ character on the display, for example, we set these pins to 0100 0001 (as per the ASCII table).

The LCD has two separate power connections: one for the LCD (pins 1 and 2) and one for the LCD backlight (pins 15 and 16). Connect LCD pins 1 and 16 to GND and 2 and 15 to 5V.

Depending on the manufacturer, some LCDs include a current-limiting resistor for the backlight. It is located on the back of the LCD, close to pin 15. If your LCD does not contain this resistor or if you are unsure whether it does, you must add one between 5V and pin 15. It should be safe to use a 220 ohm resistor, although a value this high may make the backlight slightly dim. For better results, check the datasheet for the maximum backlight current and choose an appropriate resistor value.

Let’s connect a potentiometer to the display. This is necessary to fine-tune the contrast of the display for best visibility. Connect one side of the 10K potentiometer to 5V and the other to Ground, and connect the middle of the pot (wiper) to LCD pin 3.

That’s all. Now, turn on the Arduino. You will see the backlight light up. As you turn the potentiometer knob, you will see the first row of rectangles appear. If you have made it this far, Congratulations! Your LCD is functioning properly.

We know that data is sent to the LCD via eight data pins. However, HD44780-based LCDs are designed so that we can communicate with them using only four data pins (in 4-bit mode) rather than eight (in 8-bit mode). This helps us save 4 I/O pins!

8-bit mode is significantly faster than 4-bit mode. This is because in 8-bit mode, data is written in a single operation, whereas in 4-bit mode, a byte is split into two nibbles and two write operations are performed.

Therefore, 4-bit mode is commonly used to save I/O pins. 8-bit mode, on the other hand, is best suited when speed is a priority in the application and at least 10 I/O pins are available.

The sketch begins by including the LiquidCrystal library. This library comes with the Arduino IDE and allows you to control Hitachi HD44780 driver-based LCD displays.

Next, an object of the LiquidCrystal class is created by passing as parameters the pin numbers to which the LCD’s RS, EN, and four data pins are connected.

In the setup, two functions are called. The first function is begin(). It is used to initialize the interface to the LCD screen and to specify the dimensions (columns and rows) of the display. If you’re using a 16×2 character LCD, you should pass 16 and 2; if you’re using a 20×4 LCD, you should pass 20 and 4.

In the loop, the print() function is used to print “Hello world!” to the LCD. Please remember to use quotation marks " " around the text. There is no need for quotation marks when printing numbers or variables.

The function setCursor() is then called to move the cursor to the second row. The cursor position specifies where you want the new text to appear on the LCD. It is assumed that the upper left corner is col=0 and row=0.

There are many useful functions you can use with LiquidCrystal Object. Some of them are listed below:lcd.home() function positions 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 the above function, use this inside a for loop for continuous scrolling.

lcd.display() function turns on the LCD display, after it’s been turned off with noDisplay(). This will restore the text (and cursor) that was on the display.

If you find the default font uninteresting, you can create your own custom characters (glyphs) and symbols. They come in handy when you need to display a character that isn’t in the standard ASCII character set.

As previously discussed in this tutorial, a character is made up of a 5×8 pixel matrix; therefore, you must define your custom character within this matrix. You can define a character by using the createChar() function.

To use createChar(), you must first create an 8-byte array. Each byte in the array corresponds to a row in a 5×8 matrix. In a byte, the digits 0 and 1 indicate which pixels in a row should be ON and which should be OFF.

The CGROM stores the font that appears on a character LCD. When you instruct a character LCD to display the letter ‘A’, it needs to know which dots to turn on so that we see an ‘A’. This data is stored in the CGROM.

CGRAM is an additional memory for storing user-defined characters. This RAM is limited to 64 bytes. Therefore, for a 5×8 pixel LCD, only 8 user-defined characters can be stored in CGRAM, whereas for a 5×10 pixel LCD, only 4 can be stored.

Creating custom characters has never been easier! We’ve developed a small application called Custom Character Generator. Can you see the blue grid below? You can click on any pixel to set or clear that 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.

There’s no limit to what you can create. The only limitation is that the LiquidCrystal library only supports eight custom characters. But don’t be sad, look at the bright side; at least we have eight characters.

After including the library and creating the LCD object, custom character arrays are defined. The array consists of 8 bytes, with each byte representing a row in a 5×8 matrix.

This sketch contains eight custom-characters. Take, for example, the Heart[8] array. You can see that the bits (0s and 1s) are forming the shape of a heart. 0 turns the pixel off, and 1 turns it on.

In the setup, we use the createChar() function to create a custom character. This function accepts two parameters: a number between 0 and 7 to reserve one of the eight supported custom characters, and the name of the array.

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.

The first parameter in this function is a number between 0 and 7, or we have to reserve one of the 8 supported custom characters. The second parameter is the name of the array of bytes.

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.

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.

After 40 spaces, the function will loop back to the first character. With this function in the loop part of your sketch, you can build a scrolling text function.

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.

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.

You can find the previous article here. It contains a description of the LCD module, shows you how to connect the display to your Arduino UNO board and describes the basic rules of operating it using the software. Still, it needs to be admitted here that there is only a limited number of applications for an LCD alone, because in the case of such a simple LCD module no settings can be entered. To do so, you need a keyboard, which we will discuss in detail in one of the future articles, but now let us use a ready-made solution from the Arduino ecosystem – a board from Olimex – SHIELDLCD16x2.

This is a shield board which extends Arduino capabilities, equipped with an LCD module (2 lines of 16 characters each), 4 buttons and 8 additional GPIO lines. On the board, there is a PIC processor which communicates with Arduino UNO via the TWI interface. With access to a library of functions, operating this module with a built-in microcontroller should not cause any major problems. Let"s start with preparing the module for operation.

There are two steps to prepare the module for work: hardware and software. The first one is simply to plug the shield into the Arduino UNO board. The second one requires you to install a library of module operating functions.

To install the library, go to the module manufacturer"s website i.e. Olimex. Then, in the search box (next to the Search button) enter the part of the module name "LCD16x2". (Figure 1). Click on the Search button. When this text was being created, the search retuned two results – please, select "SHIELD-LCD16x2".

Under the description of the module, you can find the "SOFTWARE" section (figure 2). Each line of text in this section is also a link to a file that can be downloaded from the Olimex website. At this point, we are looking for the link saying: "OLIMEXINO-328 + SHIELD-LCD16x2 – a library and set of demo examples".

Download the ZIP file available at this link to your computer. Of course, it is worth having a look at the available examples, but for our needs it is enough to install the library saved in the LCD16x2 catalogue.

The Arduino IDE allows for various different ways of installing libraries. In this case, the easiest way is to upload the sources to the project directory, which also contains a libraries subdirectory. The project directory is created during the installation of Arduino IDE, and Windows usually places it (in the Polish language version) in subdirectory Ten Komputer → Dokumenty → Arduino. To add the library sources to today"s example, just move the LCD16x2 directory to the libraries folder. Once you"ve done that, launch the Arduino IDE.

Before getting started with your own program, you should read examples of using the LCD16x2.h library of functions available in the Examples directory. It is a much more effective method of learning than reading documentation, although it is worth remembering about the latter as well.

As mentioned before, the shield communicates with the UNO board using a serial interface. It"s easy to guess that the functions described in the previous article must be modified, because they used a parallel, 4-bit interface. As you can imagine, the microcontroller on the shield board communicates with the LCD character display module in the same way, but our Arduino UNO cannot "see" the display, and the control is done indirectly. Therefore, start the program by adding libraries to support the appropriate serial interface and the display module mounted on the shield board.

To make it simple, in order not to use the long library name, it is recommended to assign to it the lcd alias. We will use it by writing the name of the library function after the dot.

As you remember from the previous article, programs created for Arduino are divided into two parts: the initialization function and the infinite loop. The commands of the first one are written in the void setup() function, and of the latter – in the void loop() function. The commands contained within the setup function are executed only once, while those within the infinite loop are executed throughout the program.

The initialization function starts the TWI interface, clears the LCD screen, and turns on the display backlight at the maximum LED light intensity (0 parameter turns off the backlight).

In the case of the Olimex board, if no button is pressed, the button readout function returns only ones, while pressing the button resets the related bit to zero.

It is possible to operate on bits that are logic zeros, but it is much more convenient and easier for further analysis, if the corresponding bit is set. This is done by the ones" complement:

If a bit is set, it is better to test its level using the Boolean product method. It is only true if both components are true. Further bit positions can be tested by using constants: 0x01 for a bit in position 0, 0x02 – in position 1, 0x04 – in position 2, 0x08 – in position 3, etc. It"s all the same whether you test the bits using hexadecimal, binary or decimal numbers, but once you get the hang of it, hexadecimal numbers are easy to write. You can see that the subsequent hexadecimal numbers used to test the bit position are the powers of 2.

The “buttons” variable contains information about the buttons pressed. Using “if ... else” causes that the processing of the button ends when the condition is fulfilled. This reduces the program runtime, but it also has the downside – the buttons have their own hierarchy and it is not possible to read the status of two or more pressed buttons like in the case of the combination of the Shift + Ctrl buttons on a PC.

Mask 0x01 corresponds to the first button on the left, while 0x08 corresponds to the first button on the right. The program numbers the buttons by giving the pressed variable a value corresponding to the conventional button number. Then, this number is shown on the LCD screen, at the position starting in the first row and the first column. The message is displayed only if the pressed value is different from 0. Otherwise, the message "No button" is displayed, indicating that no button is pressed. The message is terminated with three spaces so that when overlaid on "1 is pressed" (which is longer) the last characters of the caption are cleared.

The whole sketch is available in the resources attached to the article. Compile it and upload it to the Arduino UNO microcontroller memory using the Ctrl+U shortcut (Sketch → Upload).

The LCDduino board enables users to create many applications/projects that require a 16×2 LCD display and Arduino. The board has the exact size of 16×2 LCD and can be installed on the backside of the LCD. This is a low-cost solution that has onboard Arduino + LCD so no extra Arduino Nano or Arduino board is required. The Arduino compatible hardware includes onboard programming and boot-loader connectors, Atmega328 microcontroller, and 16×2 LCD interface. Each Arduino I/O Pin including the VCC and GND is exposed to the connectors for easy connection with sensors and other devices. The board enables the easy interface of many devices and sensors. The operating power supply is 7 to 15V DC.

After the board assembly, the brand new Atmega328 microcontroller requires burning the bootloader before it can be programmed using Arduino IDE. Refer to the connection diagram and follow the links below to learn more about bootloader and Arduino IDE programming.

Arduino example code is provided below to test the project. This code will help you to convert this board into a 0 to 5V Voltmeter. Just connect the DC source at analog in A0 to measure the DC voltage.

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Today, among the various projects with Arduino used in the market, those that involve integration with LCD displays for the display of information stand out.

In this case, the I2C module needs to be connected to the display to have all its communication reduced to four wires: two for power and two for signal.

In order not to make a mistake in the numbering of the pinout, it is important to carefully observe the characteristics of each pin and their locations on the Arduino.

Meanwhile, pin 5 (R/W), connected to GND, demonstrates the read and write signal of the display, and pin 6 (E) serves to enable or disable the signal.

In addition, pins 15 (LED+) and 16 (LED-) will be responsible for supplying power to the LEDs at the bottom of the display. It is possible to connect pin 15 using:Using 2 resistors of 220 ohms in parallel;

With the proper connections, it"s time to program the Arduino by connecting it to the computer and opening the official Arduino IDE in its updated version.

Furthermore, despite being highly efficient, LCD technology is not new to the market, which lowers its cost in relation to other displays with similar benefits.

In this project, we will connect an LCD screen to an Arduino and use it to display some basic text. This covers both the physical connections and the programming required to get an LCD to work. If this is your first project then we recommend that you familiarise yourself with programming an Arduino first.

This project consists of two parts, one which prints Hello World, The DIY Life and a second which prints The DIY Life and then prints a seconds since start-up counter on the second line.

The screens we are covering in this project have 16 pin parallel interfaces, meaning that the Arduino has to send data on multiple pins at the same time in order to change the screen text. Fortunately, the Arduino has a built in library for LCD screens which are compatible with the Hitachi HD44780 driver so we can make use of the built in function library and do not have to manually code functions to control the screen.

To understand the basic on how the screen is operated, there are three pins which control the registers (RS, RW and E), then 8 data transfer pins (D0-D7) and finally a set of pins to provide power, control the contrast and turn the backlight on and off. For displaying general text you only need to make use of 4 of the data transfer pins as the screen will be running in 4 bit mode.

Firstly you need to connect the screen up as shown in the diagram below. This can be done in one of two ways. You can solder a wire ribbon onto the screen and then pins on to the ends of the wires which then plug directly into the Arduino or you can solder a pin header onto the screen and plug it into a breadboard which you can then connect to the Arduino using jumpers.

The 10K pot is used to adjust the contrast of the screen. The 220Ω resistor is connected along the positive supply for the back light in order to limit the current.

The pin connections to the LCD screen are as follows: Pin 10, 11 and 12 are used to control the registers and are connected to the E, RW and RS pins respectively. Pins 2,3,4 and 5 are the data transfer pins and are connected to d7, d6, d5 and d4 respectively. Be careful when connecting the pins as the numerical sequence on the Arduino pins is the opposite to the screen pins.

Now you can begin the coding. For the first example, we will only be using the setup loop as we just need the screen to display “Hello World” and “The DIY Life” on the screen without any further changes.

We begin by importing the Liquid Crystal library. This enables us to use short functions to control the screen instead of having to manually code each letter or cursor movement.

Now we move on to the setup code method. We first tell the lcd object how many columns and rows or characters our screen has. In this case the screen size is 16 x 2. We then clear the screen to ensure that it is blank, set the cursor to the first row and first character, then begin sending the text “Hello World” to the screen. We then tell the cursor to move to the second row of characters and print “The DIY Life”.

If you have connected everything correctly then the screen should now display Hello World on the first line and The DIY Life on the second line. You may need to play around with the contrast adjustment on the 10K pot to make the text visible, this adjustment is shown in the video below:

Now we can move onto using the loop function to constantly change information on the screen.  First we remove “Hello World” and move “The DIY Life” to the first row, this is all done in the setup function.

When you run this code you should see The DIY Life in the first row and a counter which updates every second in the second row and runs until 100 seconds. The counter in operation is shown in the video below:

You have now covered the basics on connecting an LCD screen to the Arduino and using the built in control functions to change the text displayed on the screen.

Would you like to learn more about this project? Are you interested in projects similar to this one? Then Practical Arduino Projects is the book for you, available now on Amazon as an eBook or in Print form.

In this digital age, we come across LCDs all around us from simple calculators to smartphones, computers and television sets, etc. The LCDs use liquid crystals to produce images or texts and are divided into different categories based on different criteria like type of manufacturing, monochrome or colour, and weather Graphical or character LCD. In this tutorial, we will be talking about the 16X2 character LCD Modules.

The 16x2 LCDs are very popular among the DIY community. Not only that, but you can also find them in many laboratory and industrial equipment. It can display up to 32 characters at a time. Each character segment is made up of 40 pixels that are arranged in a 5x8 matrix. We can create alphanumeric characters and custom characters by activating the corresponding pixels. Here is a vector representation of a 16x2 LCD, in which you can see those individual pixels.

As the name indicates, these character segments are arranged in 2 lines with 16 characters on each line. Even though there are LCDs with different controllers are available, The most widely used ones are based on the famous HD44780 parallel interface LCD controller from Hitachi.

The 16x2 has a 16-pin connector. The module can be used either in 4-bit mode or in 8-bit mode. In 4-bit mode, 4 of the data pins are not used and in 8-bit mode, all the pins are used. And the connections are as follows:

Vo / VEE Contrast adjustment; the best way is to use a variable resistor such as a potentiometer. The output of the potentiometer is connected to this pin. Rotate the potentiometer knob forward and backwards to adjust the LCD contrast.

EnableSends data to data pins when a high to low pulse is given; Extra voltage push is required to execute the instruction and EN (enable) signal is used for this purpose. Usually, we set en=0, when we want to execute the instruction, we make it high en=1 for some milliseconds. After this we again make it ground that is, en=0.

The 16x2 LCD modules are popular among the DIY community since they are cheap, easy to use and most importantly enable us to provide information very efficiently. With just 6 pins, we can display a lot of data on the display.

The module has 16 pins. Out of these 16 pins, two pins are for power, two pins are for backlight, and the remaining twelve pins are for controlling the LCD.

If you look at the backside of the module you can simply see that there are not many components. The main components are the two controller chips that are under the encapsulation. There is an onboard current limiting resistor for the backlight. This may vary from different modules from different manufacturers. The only remaining components are a few complimentary resistors for the LCD controller.

In the module PCB, you may have noticed some unpopulated footprints. These footprints are meant for charge pump circuits based on switched capacitor voltage converters like ICL7660 or MAX660. You can modify your LCD to work with 3.3V by populating this IC and two 10uF capacitors to C1 and C2 footprint, removing Jumper J1 and adding jumper J3. This modification will generate a negative contrast voltage of around 2.5V. This will enable us to use the LCD even with a VCC voltage of 3.3V.

Another issue to be concerned about is the oscillator frequency, i.e. when the supply voltage is reduced, the built-in clock frequency will also get reduced. The Rosc should be changed to a suitable value if any timing issues or command execution issues occur. The typical value of the Rosc for 5V VCC is 91KOhms.

To test whether a 16x2 LCD works or not, connect the VDD, GND and backlight pins to 5v and GND. Connect the centre terminal of a 10K variable resistor to the VEE pin. Connect the other two terminals to VCC and GND. Simply rotate the variable resistor you will see that the contrast will be adjusted and small blocks are visible. If these rectangles are visible, and you were able to adjust the contrast, then the LCD is working

There are 16 pins on the display module. Two of them are for power (VCC, GND), one for adjusting the contrast (VEE), three are control lines (RS, EN, R/W), eight pins are data lines(D0-D7) and the last two pins are for the backlight (A, K).

The 16x2 LCD has 32 character areas, which are made up of a 5x8 matrix of pixels. By turning on or off these pixels we can create different characters. We can display up to 32 characters in two rows.

Yes, we can. We can store up to eight custom characters in the CGRAM (64 bytes in size) area. We can create load the matrix data for these characters and can recall when they need to be displayed.

Controlling the LCD module is pretty simple. Let’s walk through those steps. To adjust the contrast of the LCD, the Vo/ VEE pin is connected to a variable resistor. By adjusting the variable resistor, we can change the LCD contrast.

The RS or registry select pin helps the LCD controller to know whether the incoming signal is a control signal or a data signal. When this pin is high, the controller will treat the signal as a command instruction and if it’s low, it will be treated as data. The R/W or Read/Write pin is used either to write data to the LCD or to read data from the LCD. When it’s low, the LCD module will be in write mode and when it’s high, the module will be in reading mode.

The Enable pin is used to control the LCD data execution. By default, this pin is pulled low. To execute a command or data which is provided to the LCD data line, we will just pull the Enable pin to high for a few milliseconds.

To test the LCD module, connect the VDD, GND, and backlight pins to 5v and GND. Connect the center terminal of a 10K variable resistor to the VEE pin. Connect the other two terminals to VCC and GND as per the below connection diagram-

Simply rotate the variable resistor you will see that the contrast will be adjusted and small blocks are visible. If these rectangles are visible, and you were able to adjust the contrast, then the LCD is working.

Let’s see how to connect the LCD module to Arduino. For that first, connect the VSS to the GND and VDD to the 5V. To use the LCD backlight, connect the backlight Anode to the 5V and connect the backlight cathode to the GND through a 220Ωresistor. Since we are not using the read function connect the LCD R/W pin to the GND too. To adjust the contrast, connect the centre pin of a 10KΩ trimmer resistor to the VEE pin and connect the side pins to the VCC and GND. Now connect the registry select pin to D12 and Enable pin to D11.

Now let’s connect the data pins. The LCD module can work in two modes, 8-bit and 4-bit. 8-bit mode is faster but it will need 8 pins for data transfer. In 4-bit mode, we only need four pins for data. But it is slower since the data is sent one nibble at a time. 4-bit mode is often used to save I/O pins, while the 8-bit mode is used when speed is necessary. For this tutorial, we will be using the 4-bit mode. For that connect the D4, D5, D6 and D7 pins from the LCD to the D5, D4, D3 and D2 pins of the Arduino.

Here is the actual circuit. It is built as per the connection diagram provided. All the connections are made using standard male to male jumper wires.

The following Arduino 16x2 LCD code will print Hello, World! on the first line of the display and the time the Arduino was running in seconds on the second line.

Now let’s discuss the code. As usual, the sketch starts by including the necessary libraries. For this tutorial, we will be including the LiquidCrystal library from Arduino. This library is compatible with LCDs based on the Hitachi HD44780, or any compatible chipset. You can find more details about this library on the Arduino website.

Let’s create an object to use with the LiquidCrystal library. The following line of code will create an object called lcd. We will be using this object in the entire code to access the library functions. The object is initialized with the pin numbers.

Now let’s look at the setup()function. The lcd.begin function is used to initialize the LCD module. This function will send all the initialization commands. The parameters used while calling this function are the number of columns and the number of rows. And the next function is lcd.print. with this function, we have printed the word Circuit Digest! to the LCD. Since the LCD cursor is set to home position within the lcd.begin, we don’t need to set any cursor position. This text will stay there for two seconds. After that, the text will scroll from left to right until the entire text is out of the display. To scroll the display to the right, we have used the function lcd.scrollDisplayRight. After that, to clear display, we used lcd.clear, this will clear any characters on the display.

Now let’s look at theloop function. The for loop will count from 0 to 9, and when it reaches 9, it will reset the count and repeat the process all over again. lcd.setCursor is used to set the cursor position. lcd.setCursor(8, 1) will set the LCD cursor to the eighth position in the second row. In the LCD, the first row is addressed as 0 and the second row is addressed as 1. And the lcd.print(i) will print the count value stored in the variable i to the display.

Wrong characters are displayed: This problem occurs usually when the LCD is not getting the correct data. Make sure you are sending the correct ASCII value. If you are sending the correct ASCII characters, but still showing the wrong one on the LCD, check your connections for loose contact or short circuits.

Display shows Black boxes or does not show anything: First thing to do in these situations is to adjust the contrast voltage by rotating the variable resistor. This will correct the contrast value and will give you a visible readout.

Contrast is Ok, but still no display: Make sure to provide a sufficient time delay in between sending each character. Because if you don’t give enough time to process the data the display will malfunction.

Contrast and delay are ok, but still no display: Make sure you are powering the LCD from a 5V source. By default, these displays won’t work with a supply voltage below 5V. So if you are using the display with a 3.3V microcontroller make sure to power the display from 5V and use level shifters in between the display and the microcontroller.

In this project we will provide the input voice using Google Voice Keyboard via a Android App (BlueTerm) and print the text on 16x2 LCD using Raspberry Pi.

In this tutorial we are interfacing a Liquid Crystal Display (LCD) module with the Raspberry Pi Pico using Micropython to display strings, and characters on the LCD.

We used some Python scripts to find the local IP address of your Raspberry Pi on the network and display it on the 16x2 LCD Screen. We also added the script in the Crontab so that it can be run on every 10 minutes and we will have the updated IP address every time.

ERM4002SYG-1 is 40 characters wide,2 rows character lcd module,SPLC780C controller (Industry-standard HD44780 compatible controller),6800 4/8-bit parallel interface,single led backlight with yellow green color included can be dimmed easily with a resistor or PWM,stn-lcd positive,dark blue text on the yellow green color,wide operating temperature range,rohs compliant,built in character set supports English/Japanese text, see the SPLC780C datasheet for the full character set. It"s optional for pin header connection,5V or 3.3V power supply and I2C adapter board for arduino.

It"s easily controlled by MCU such as 8051,PIC,AVR,ARDUINO,ARM and Raspberry Pi.It can be used in any embedded systems,industrial device,security,medical and hand-held equipment.

Of course, we wouldn"t just leave you with a datasheet and a "good luck!".For 8051 microcontroller user,we prepared the detailed tutorial such as interfacing, demo code and Development Kit at the bottom of this page.

The Arduino board has a wide variety of compatible displays that you can use in your electronic projects. In most projects, it’s very useful to give the user some sort of feedback from the Arduino.

With the TFT display you can display colorful images or graphics. This module has a resolution of 480 x 320. This module includes the SD card socket and SPI FLASH circuit.

This is a tiny display with just 1 x 0.96 Inch. This display has a black background, and displays characters in white. There are other similar displays that can show the characters in other colors.

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A complete device consists of functional blocks, many of which can be used multiple times. For example, if you build a frequency counter with a microcontroller, you will need to use the same components as is in the case of building a time relay, plus the amplifier unit. The system described here can be understood as a microcontroller with its surrounding units (resistors, capacitators, quartz and other), display, buttons, and terminals/connectors. Of course, the frequency counter will not require a transmitter that switches on an external device, and the time relay will not need a broadband amplifier, but the core remains the same. Therefore, the key to making apps on your own is to understand the principles of operation of each of the functional blocks, and then to combine their functionalities.

Such platforms as Arduino do not require any background knowledge on the operation of every single component from the user. You can simply connect the base board with a module/extension and make a full functional, up and running app. On the other hand, if you do not have any basic knowledge of the components, then in the case of problems you will probably struggle looking for the solution on your own. The truth is that when using Arduino components, you usually expect an instant effect. It is hard to reconcile such expectations with a need to acquire specific knowledge, because you just need to enter a few commands to see the first effects on the display, but understanding the whole process takes more time.

Having in mind the differences mentioned above, each of the articles in this cycle is going to be divided into two parts. The first one is going to describe how to reach the goal discussed in the article. The second one is focused on the principles of functioning of a given unit or solution.

We will start with the LCD module, because thanks to it you can see the effect of your work really soon. Then, the other elements of the user interface and the selected external systems (sensors and executive elements) will be discussed. In the meantime, you will get familiar with some useful tricks and programming methods. This is all possible thanks to the Arduino platform, which is budget-friendly, easily available and will let you use your new knowledge to build complete devices and their prototypes.

The basic interface between the microcontroller and the user is usually composed of a display and a button or a set of buttons. The display is used to inform the user about microcontroller activity, whereas the buttons – sometimes replaced with pulse generator – can be used to enter a command or data. The range of available products includes various kinds of displays (including displays equipped with a touch panel), among which character LCDs with a HD44780 controller have become an informal standard much appreciated by the users.

In the first example, an Arduino UNO R3 board, a breadboard, a character LCD module with two 16-character lines (verses) in each of them, and a few connection cables are going to be used. Of course, it is just a suggestion – the display can be connected in any way you want, for example by way of soldering it to the board. Here, we propose a method which gives you the widest possibility to modify and change the system of connections.

If the display module features goldpins, just stick it into the breadboard. Then, connect the display with Arduino UNO board, as described in Table 1.

You need to remember that if you have GND connected from the Power connector to the breadboard, you can make connections within the breadboard without the need to make a connection to the Power connector every time.

You have to use the Power connector, because it will supply power to the display. The Analog In connector is located right next to the Power connector, so the microcontroller terminals available there are used as the most convenient ones. However, do not get misled by the name – in order to manipulate the display module, digital outputs are required, not analogue inputs/outputs. The connector is called Analog In, as optional analogue inputs are available here, which still can be set up to operate in different modes, including as digital outputs. The A0 analogue input is PC0 port, A1 – PC1, and so on (see also: terminals of the ATmega328PU microcontroller).

From among many programmable controllers available for Arduino, a LiquidCrystal library was selected to control the LCD operation. After making a draft, we will add the library in the first line of the program, using the command: #include. With the display already connected to microcontroller according to the instructions above, you can make the first draft controlling the LCD module.

Connect the Arduino board to your computer via the USB port. Choose File and then New (Ctrl+N) from the Arduino menu. You will see a window similar to the one in Figure1. The key word “void” informs you that a function will be created here that does not return any value. The word “void” is followed by the name of the function, and the opening and closing brace brackets, “{” and “}”, inform us about its beginning and end.

When you make a new draft, the Arduino environment informs you about the need to define two special functions: one is void setup(), which describes the configuration of the microcontroller and comprises instructions performed once at the beginning of the program operation, and the other one is void loop(), with operations performed in an infinite loop.

Why the application program must be launched in an infinite loop? Windows or Linux apps run under the control of t