lcd display commands free sample

We come across Liquid Crystal Display (LCD) displays everywhere around us. Computers, calculators, television sets, mobile phones, and digital watches use some kind of display to display the time.

An LCD screen is an electronic display module that uses liquid crystal to produce a visible image. The 16×2 LCD display is a very basic module commonly used in DIYs and circuits. The 16×2 translates a display of 16 characters per line in 2 such lines. In this LCD, each character is displayed in a 5×7 pixel matrix.

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 backward to adjust the LCD contrast.

A 16X2 LCD has two registers, namely, command and data. The register select is used to switch from one register to other. RS=0 for the command register, whereas RS=1 for the data register.

Command Register: The command register stores the command instructions given to the LCD. A command is an instruction given to an LCD to do a predefined task. Examples like:

Data Register: The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD. When we send data to LCD, it goes to the data register and is processed there. When RS=1, the data register is selected.

Generating custom characters on LCD is not very hard. It requires knowledge about the custom-generated random access memory (CG-RAM) of the LCD and the LCD chip controller. Most LCDs contain a Hitachi HD4478 controller.

CG-RAM address starts from 0x40 (Hexadecimal) or 64 in decimal. We can generate custom characters at these addresses. Once we generate our characters at these addresses, we can print them by just sending commands to the LCD. Character addresses and printing commands are below.

LCD modules are very important in many Arduino-based embedded system designs to improve the user interface of the system. Interfacing with Arduino gives the programmer more freedom to customize the code easily. Any cost-effective Arduino board, a 16X2 character LCD display, jumper wires, and a breadboard are sufficient enough to build the circuit. The interfacing of Arduino to LCD display is below.

The combination of an LCD and Arduino yields several projects, the most simple one being LCD to display the LED brightness. All we need for this circuit is an LCD, Arduino, breadboard, a resistor, potentiometer, LED, and some jumper cables. The circuit connections are below.

Liquid Crystal Display(LCDs) provide a cost effective way to put a text output unit for a microcontroller. As we have seen in the previous tutorial, LEDs or 7 Segments do no have the flexibility to display informative messages.

This display has 2 lines and can display 16 characters on each line. Nonetheless, when it is interfaced with the micrcontroller, we can scroll the messages with software to display information which is more than 16 characters in length.

The LCD is a simple device to use but the internal details are complex. Most of the 16x2 LCDs use a Hitachi HD44780 or a compatible controller. Yes, a micrcontroller is present inside a Liquid crystal display as shown in figure 2.

It takes a ASCII value as input and generate a patter for the dot matrix. E.g., to display letter "A", it takes its value 0X42(hex) or 66(dec) decodes it into a dot matrix of 5x7 as shown in figure 1.

Power & contrast:Apart from that the LCD should be powered with 5V between PIN 2(VCC) and PIN 1(gnd). PIN 3 is the contrast pin and is output of center terminal of potentiometer(voltage divider) which varies voltage between 0 to 5v to vary the contrast.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

An example C program is given here to show how the LCD can be set up. The connection of the LCD to the microcontroller is shown in Figure 6.9 (if you are using the EasyPIC 7 development board, all you have to do is just connect the LCD to the board). PORT B lower pins (RB0 to RB3) are connected to the upper 4 bits of the LCD (DB4 to DB7). In addition, RB4 and RB5 pins are connected to LCD RS and E pins, respectively.

Lcd_Initialise: This function initialises the LCD in 4-bit mode, as described earlier. The enable clock pulses are sent to the LCD by calling to function Toggle_E, which simply sets the E line to HIGH and then LOW. The 4-bit LCD commands are sent using function Lcd_Write_Cmd.

Lcd_Write_Cmd: This function receives a byte, separates it into two nibbles, sends the high nibble, followed by the low nibble. The E line is toggled after each output.

Lcd_Write_Char: This function sends a character to the LCD. The upper nibble is sent first, followed by the lower nibble. Line E is toggled between each output.

The Serial LCD Kit includes all the parts you need to add a serial "backpack" to a 16x2 LCD. The kit includes a pre-programmed ATmega328 microprocessor, which reads a serial stream of data and (after a little heavy-lifting) instantly displays it on the LCD. Interfacing the Serial LCD with an Arduino, or other serial-enabled devices, allows you to easily print GPS coordinates, short messages or any other information onto the LCD.

This tutorial will cover everything you need to know to get up and running with the Serial Enabled LCD Kit. We"ll first go over assembly so you can turn that bag-o-parts into something that hopefully resembles any pictures you may have seen of the kit.

Following assembly, we"ll touch on how to actually use the Serial LCD Kit. Specifically, we"ll go over how you"d use the thing with everybody"s favorite development board, Arduino. There"ll be example code galore, and you can even make your own LCD clock! It"s gonna be pretty crazy...

Finally, you"ll need something to send a serial stream of data to the display. An Arduino works great (any variety, this isn"t limited to the Uno) if you want to automate the serial data stream. FTDI breakouts or RS-232 level shifters work if you just want to connect the display to your computer and send data via a terminal program. For what it"s worth, this tutorial will focus on connecting the display to an Arduino.

The goal of the Serial LCD Kit is to make controlling an LCD simple and to make wiring to it even simpler. If you wanted, you could abstain from using the serial backpack and wire an Arduino directly up to the LCD. To that point, there are loads of great examples, and even some Arduino libraries, that make interfacing a microcontroller directly to an LCD very easy. However, because the LCD is driven by a parallel interface, those examples require a tangle of wires and anywhere from 6 to 11 pins of the Arduino to control the thing.

The microcontroller on the Serial LCD Kit takes care of all of that nasty wiring, so you only need one pin to control the LCD. The Serial LCD"s on-board microcontroller parses any incoming commands or characters, and then sends the proper data to the LCD over the multi-wire parallel interface. It"s a magic black box, and you don"t have to care how it does its job, just that it does it. So let"s get it built...

What you"ve got in front of you right now is not yet a Serial LCD Kit. First, we"ve got to turn that bag of parts into a Serial LCD Kit, which will require soldering. If you"ve never soldered before, don"t fret! This is one of the easier soldering projects, every part is through-hole, and well-spaced. If this is your first time though, I"d encourage you to take a trip over to one of our excellent soldering tutorials before picking up the iron.

First, pick out the big, ferrari-red PCB. See how one side has white silkscreen printed onto it? This is the top of the PCB. You"ll stick almost every part in on this side and solder the pins to the opposite side. The only time we"ll stray from that is when soldering the LCD, which is the last step.

Wait...something"s missing...oh, hi LCD! To connect the LCD to the PCB, we"ve included a straight 16-pin header with the kit. You"ll need to solder this header to both the PCB and the LCD. Solder it first to the LCD, stick the shorter pins into the LCD. Make sure the longer legs are extended out from the back of the LCD and solder all 16-pins on the top side of the LCD. Effort to keep the pins as perpendicular to the LCD as possible.

With the header soldered to the LCD,you"ll finally be able to connect the display to the PCB. Remember, we"re sticking this part into the bottom side of the PCB, and soldering to the top. Solder up all 16 pins, and that should be it.

Before you can display anything on the LCD, you"ll have to connect something to it. Only three wires are necessary to use the Serial LCD Kit: RX, GND and VCC. Plug the included 3-wire jumper cable into its mating JST connector that you soldered onto the PCB. This color coded cable has two wires for power, and one for receiving serial data. The red and black wires correspond to +5V and GND, respectively, and the yellow wire is RX.

You"ll need to figure out how you"re going to powerthe LCD Kit. It doesn"t have a regulator on-board, so it"s up to you to supply a clean, regulated 5V power source. If you"re using an Arduino, you could power the Kit off of the 5V and GND pins – connect red to 5V and black to GND. Otherwise, there"s a ton of options out there for power; you could use a USB adapter, a 5V wall-wart, a breadboard power supply. The list just goes on. Just make sure you"re not supplying any more than 5V (a little less may work, but you"ll lose some brightness).

After powering the Serial LCD Kit, you should notice the backlight turn on. If the contrast is properly adjusted, you might see the splash screen flash for a second or two. Most likely though, the contrast won"t be set correctly, so you won"t see a splash screen. In that case, you may see anything from 32 white boxes to absolutely nothing. You"ll have to be quick about it, because the splash screen only remains for a couple seconds before going blank, but try turning the trimpot knob until you"ve got a good view of the characters on the LCD.

The "Serial" in the Serial LCD Kit can be a little confusing. What it really means is TTL serial, not to be confused with RS-232 serial. The voltage on the RX line should only go between 0 and +5V. If you"re using a microcontroller (like an Arduino) to talk with the LCD, then you most likely don"t have to worry. Just don"t hook up a PC"s serial port straight to the LCD and expect it to survive.

Connect the Arduino to the Serial LCD as follows. If you have a wire stripper, you may want to expose a few millimeters more of wire to allow them to stick really nicely into the Arduino"s headers.

Here"s a simple example sketch, which uses the SoftwareSerial library (which is included with recent versions of Arduino) to instill our Arduino with more than just the one, hardware, serial port. Now we can use the hardware serial port to listen to the serial monitor, and the second serial port can be used to talk to the LCD.

Now, plug in your Arduino and upload the code. Open up the serial monitor, and make sure it"s set to 9600. Type “Hello, world” into the serial monitor and send it over to the Arduino. The LCD should echo your greeting. Take the LCD for a test drive, discover all the characters it can display!

You"ll quickly notice, that the code is severely lacking any sort of clear display command, but don"t think for a second that the Serial LCD Kit doesn"t have a clear display command. It"s got commands up the wazoo! The Serial LCD Kit is set up to accept commands that control the backlight, baud rate, and all sorts of display functionality, like clearing the screen. Have a look at the Kit"s “datasheet”, which lists all of the characters and commands you can send to the display. I wrote that, but I understand if it"s all gobbledygook to you right now.

The commands are divided into three groups: backlight, baud rate, and special commands. Each command requires that you send at least two bytes to the display. For instance to set the backlight, you first have to send the backlight control byte (0x80, or decimal 128) followed by a byte with any value from 0 to 255. Sending a 0 will turn the backlight completely off, 255 will turn it all the way on, 127 will set it to about 50%, and so on. The backlight setting is stored in the Serial LCD Kit"s memory and will be restored when the LCD is turned off and on.

What we really care about right now, though, is clearing the display, which requires a special command. To issue a special command to the LCD, you first have to send 0xFE (or decimal 254) which tells the display to go into special command mode, and wait for a data byte. The clear display command is 0x01 (or decimal 1), that command should be sent immediately after sending the special command byte. So to clear the display we need to send two bytes: 254 (0xFE) followed by 1 (0x01). Check out the datasheet link for all of the special commands. You can do all sorts of fun stuff: scroll the display, turn it on/off and control the cursor.

Our next piece of example code, Serial_LCD_Kit_Clock, delves into sending special commands to the LCD with an Arduino. There are individual functions that clear the display (clearDisplay()), set the backlight (setBacklight(byte brightness)), and set the cursor (setLCDCursor(byte cursor_position)), feel free to copy these and add them to any code you"d like.

This is a good start, but there"s plenty of room for growth. Try adjusting the brightness of the display based on what time it was. Make it the brightest at midnight, dimmest at noon. What else can you do with the code?

Now then, that should be enough to get you on your way to using the Serial LCD Kit with a serial interface. If you"re happy with that, and don"t want your mind blown, I suggest you stop reading here.

Oh, you"ve taken the red pill? Well then you get to learn the Serial LCD Kit"s very deep, dark secret. It may not look anything like one, but the LCD Kit is actually Arduino-compatible. It has an ATmega328, just like the Arduino, and that ATmega328 has a serial bootloader, just like an Arduino. It can be programmed via a USB-to-Serial board. This means you can hook up all sorts of sensors, blinkies and other I/O to the Kit itself, while continuing to use the LCD to display any info you"d like. The 6-pin serial programming port on the right hand side of the PCB can be connected to an FTDI Basic Breakout.

With the FTDI board connected, and Arduino open, simply select the corresponding COM port in the Tools>Serial Port menu, and select Arduino Duemilanove or Nano w/ ATmega328 under the Tools>Boards menu. Though it probably won"t look like it"s doing anything, try uploading Blink, change the LED pin to 9 to at least see the backlight of the LCD flick on and off. Remember, you can download the Serial LCD Kit firmware here. If you ever want to turn it back into a Serial LCD, upload it to the LCD like you would any sketch.

If you want to be really adventurous, and get the most out of the Serial LCD Kit, I"d recommend first taking a trip over to where the Serial LCD Kit"s source code is hosted and getting a good idea how the code works. That firmware is written as an Arduino sketch, and uses a great little Arduino library named LiquidCrystal to control the LCD. The LiquidCrystal library makes controlling the LCD with an Arduino super-simple.

You should also get a good feeling for the kit"s schematic. There are a few Arduino pins that can only be used with the LCD (4-9), but pins 10-13, and all of the analog pins can be used with any device you"d normally connect to an Arduino. The available pins are all broken out on the bottom of the PCB.

Remember, this part is all very extracurricular. Don"t feel at all required to use your Serial LCD Kit as an Arduino. I just wanted to let you know what"s possible with this kit.

Serial LCD Clock Example Sketch - Displays a digital clock on the Serial LCD. This is a good example of how to use special commands, like clear, with the display.

Now I"ll leave you and your Serial LCD Kit in peace. I hope you"ve learned a good amount about the display. I also hope you"re left with questions and ideas about what you"re going to do with it next. If you"ve still got questions about the display, or comments about the tutorial, please drop them in the comments box below or email us.

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.

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

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

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

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

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

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.

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.

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.

This repository contains all the code for interfacing with a 16x2 character I2C liquid-crystal display (LCD). This accompanies my Youtube tutorial: Raspberry Pi - Mini LCD Display Tutorial.

During the installation, pay attention to any messages about python and python3 usage, as they inform which version you should use to interface with the LCD driver. For example:

It is possible to define in CG RAM memory up to 8 custom characters. These characters can be prompted on LCD the same way as any characters from the characters table. Codes for the custom characters are unique and as follows:

For example, the hex code of the symbol ö is 0xEF, and so this symbol could be printed on the second row of the display by using the {0xEF} placeholder, as follows:

LCD connected to this controller will adjust itself to the memory map of this DDRAM controller; each location on the LCD will take 1 DDRAM address on the controller. Because we use 2 × 16 type LCD, the first line of the LCD will take the location of the 00H-0FH addresses and the second line will take the 40H-4FH addresses of the controller DDRAM; so neither the addresses of the 10H-27H on the first line or the addresses of the 50H-67H on the second line on DDRAM is used.

To be able to display a character on the first line of the LCD, we must provide written instructions (80h + DDRAM address where our character is to be displayed on the first line) in the Instruction Register-IR and then followed by writing the ASCII code of the character or address of the character stored on the CGROM or CGRAM on the LCD controller data register, as well as to display characters in the second row we must provide written instructions (C0H + DDRAM address where our character to be displayed on the second line) in the Instructions Register-IR and then followed by writing the ASCII code or address of the character on CGROM or CGRAM on the LCD controller data register.

As mentioned above, to display a character (ASCII) you want to show on the LCD, you need to send the ASCII code to the LCD controller data register-DR. For characters from CGROM and CGRAM we only need to send the address of the character where the character is stored; unlike the character of the ASCII code, we must write the ASCII code of the character we want to display on the LCD controller data register to display it. For special characters stored on CGRAM, one must first save the special character at the CGRAM address (prepared 64 addresses, namely addresses 0–63); A special character with a size of 5 × 8 (5 columns × 8 lines) requires eight consecutive addresses to store it, so the total special characters that can be saved or stored on the CGRAM addresses are only eight (8) characters. To be able to save a special character at the first CGRAM address we must send or write 40H instruction to the Instruction Register-IR followed by writing eight consecutive bytes of the data in the Data Register-DR to save the pattern/image of a special character that you want to display on the LCD [9, 10].

We can easily connect this LCD module (LCD + controller) with MCS51, and we do not need any additional electronic equipment as the interface between MCS51 and it; This is because this LCD works with the TTL logic level voltage—Transistor-Transistor Logic.

The voltage source of this display is +5 V connected to Pin 2 (VCC) and GND power supply connected to Pin 1 (VSS) and Pin 16 (GND); Pin 1 (VSS) and Pin 16 (GND) are combined together and connected to the GND of the power supply.

Pins 7–14 (8 Pins) of the display function as a channel to transmit either data or instruction with a channel width of 1 byte (D0-D7) between the display and MCS51. In Figure 6, it can be seen that each Pin connected to the data bus (D0-D7) of MCS51 in this case P0 (80h); P0.0-P0.7 MCS-51 connected to D0-D7 of the LCD.

Pins 4–6 are used to control the performance of the display. Pin 4 (Register Select-RS) is in charge of selecting one of the 2 display registers. If RS is given logic 0 then the selected register is the Instruction Register-IR, otherwise, if RS is given logic 1 then the selected register is the Data Register-DR. The implication of this selection is the meaning of the signal sent down through the data bus (D0-D7), if RS = 0, then the signal sent from the MCS-51 to the LCD is an instruction; usually used to configure the LCD, otherwise if RS = 1 then the data sent from the MCS-51 to the LCD (D0-D7) is the data (object or character) you want to display on the LCD. From Figure 6 Pin 4 (RS) is connected to Pin 16 (P3.6/W¯) of MCS-51 with the address (B6H).

Pin 5 (R/W¯)) of the LCD does not appear in Figure 6 is used for read/write operations. If Pin 5 is given logic 1, the operation is a read operation; reading the data from the LCD. Data will be copied from the LCD data register to MCS-51 via the data bus (D0-D7), namely Pins 7–14 of the LCD. Conversely, if Pin 5 is given a voltage with logical 0 then the operation is a write operation; the signal will be sent from the MCS51 to LCD through the LCD Pins (Pins 7–14); The signal sent can be in the form of data or instructions depending on the logic level input to the Register Select-RS Pin, as described above before if RS = 0 then the signal sent is an instruction, vice versa if the RS = 1 then the signal sent/written is the data you want to display. Usually, Pin 5 of the LCD is connected with the power supply GND, because we will never read data from the LCD data register, but only send instructions for the LCD work configuration or the data you want to display on the LCD.

Pin 6 of the LCD (EN¯) is a Pin used to enable the LCD. The LCD will be enabled with the entry of changes in the signal level from high (1) to low (0) on Pin 6. If Pin 6 gets the voltage of logic level either 1 or 0 then the LCD will be disabled; it will only be enabled when there is a change of the voltage level in Pin 6 from high logic level to low logic level for more than 1000 microseconds (1 millisecond), and we can send either instruction or data to processed during that enable time of Pin 6.

Pin 3 and Pin 15 are used to regulate the brightness of the BPL (Back Plane Light). As mentioned above before the LCD operates on the principle of continuing or inhibiting the light passing through it; instead of producing light by itself. The light source comes from LED behind this LCD called BPL. Light brightness from BPL can be set by using a potentiometer or a trimpot. From Figure 6 Pin 3 (VEE) is used to regulate the brightness of BPL (by changing the current that enters BPL by using a potentiometers/a trimpot). While Pin 15 (BPL) is a Pin used for the sink of BPL LED.

4RSRegister selector on the LCD, if RS = 0 then the selected register is an instruction register (the operation to be performed is a write operation/LCD configuration if Pin 5 (R/W¯) is given a logic 0), if RS = 1 then the selected register is a data register; if (R/W¯) = 0 then the operation performed is a data write operation to the LCD, otherwise if (R/W¯) = 1 then the operation performed is a read operation (data will be sent from the LCD to μC (microcontroller); it is usually used to read the busy bit/Busy Flag- BF of the LCD (bit 7/D7).

5(R/W¯)Sets the operating mode, logic 1 for reading operations and logic 0 for write operations, the information read from the LCD to μC is data, while information written to the LCD from μC can be data to be displayed or instructions used to configure the LCD. Usually, this Pin is connected to the GND of the power supply because we will never read data from the LCD but only write instructions to configure it or write data to the LCD register to be displayed.

6Enable¯The LCD is not active when Enable Pin is either 1 or 0 logic. The LCD will be active if there is a change from logic 1 to logic 0; information can be read or written at the time the change occurs.

The "Arduino LCD Playground" app for Android creates an interactive learning and prototyping environment to control a 1602 LCD using Bluetooth communication.

Send characters and commands to the LCD display and watch your changes in real-time. No more needing to flash an Arduino Sketch every time you would like to test a simple change to your LCD practice code!