2 line lcd display arduino manufacturer
This module works with at least the LiquidCrystal I2C and LiquidCrystal_PCF8574 libraries available in the Arduino library manager. Address 0x3F worked for me since the A0, A1, and A2 jumpers are not shorted.
Recently purchased unit has a different address than the same part number purchased a year ago. It seems that if the small board is marked MH, the address is not going to be 0x27 or 0x20 but 0x3F. With that change of address, this display works and looks great.
Google for LCM1602 and you will find many pages that mention the board - including the pinouts stated above and sample programs using the Arduino library.
Heres the scoop. The library that works with this chip set is available at this link. http://www.play-zone.ch/en/fileuploader/download/download/?d=0&file=custom%2Fupload%2FFile-1345667375.zip
I liked the idea of the 4-wire interface, but I was disappointed that no documentation was available for this part. However after a night of hacking I got it to work with my Arduino Uno. I thought Id pass along the following information to spare others the trouble.
On the software side, you have to download and install a new LiquidCrystal_I2C library for Arduino, which has the capability to talk to the LCD display over the I2C bus. Heres a link to the library. Follow the example code for the DFRobot board, which turns out to have the same configuration as this LCD, and it should fire right up for you. The LCD has white characters on a backlit blue background, and looked great.
I am on a tight budget since I have so many other hobbies as well but am getting into Arduinos and want to be able to output GPS location data for a fun project I have in mind. I want to confirm if it"s possible to get the cheap LCD I linked above working with an Arduino Pro or Uno and can I get it working with a GPS connected as well or do I need to go with the SparkFun LCD screen instead as it"s a little more ready to go?
I do have programming experience but mostly in MATLAB. I"ve looked at the Arduino sketches and don"t think it"s really too difficult so I don"t foresee any problems but it is my first microcontroller that I"m dealing with. I know a good deal about basic electronics as well so all the circuit stuff isn"t an issue.
If you’ve ever tried to connect an LCD display to an Arduino, you might have noticed that it consumes a lot of pins on the Arduino. Even in 4-bit mode, the Arduino still requires a total of seven connections – which is half of the Arduino’s available digital I/O pins.
The solution is to use an I2C LCD display. It consumes only two I/O pins that are not even part of the set of digital I/O pins and can be shared with other I2C devices as well.
True to their name, these LCDs are ideal for displaying only text/characters. A 16×2 character LCD, for example, has an LED backlight and can display 32 ASCII characters in two rows of 16 characters each.
If you look closely you can see tiny rectangles for each character on the display and the pixels that make up a character. Each of these rectangles is a grid of 5×8 pixels.
At the heart of the adapter is an 8-bit I/O expander chip – PCF8574. This chip converts the I2C data from an Arduino into the parallel data required for an LCD display.
If you are using multiple devices on the same I2C bus, you may need to set a different I2C address for the LCD adapter so that it does not conflict with another I2C device.
An important point here is that several companies manufacture the same PCF8574 chip, Texas Instruments and NXP Semiconductors, to name a few. And the I2C address of your LCD depends on the chip manufacturer.
According to the Texas Instruments’ datasheet, the three address selection bits (A0, A1 and A2) are placed at the end of the 7-bit I2C address register.
By shorting the solder jumpers, the address inputs are puled LOW. If you were to short all three jumpers, the address would be 0x20. The range of all possible addresses spans from 0x20 to 0x27. Please see the illustration below.
According to the NXP Semiconductors’ datasheet, the three address selection bits (A0, A1 and A2) are also placed at the end of the 7-bit I2C address register. But the other bits in the address register are different.
So your LCD probably has a default I2C address 0x27Hex or 0x3FHex. However it is recommended that you find out the actual I2C address of the LCD before using it.
Connecting an I2C LCD is much easier than connecting a standard LCD. You only need to connect 4 pins instead of 12. Start by connecting the VCC pin to the 5V output on the Arduino and GND to ground.
Now we are left with the pins which are used for I2C communication. Note that each Arduino board has different I2C pins that must be connected accordingly. On Arduino boards with the R3 layout, the SDA (data line) and SCL (clock line) are on the pin headers close to the AREF pin. They are also known as A5 (SCL) and A4 (SDA).
After wiring up the LCD you’ll need to adjust the contrast of the display. On the I2C module you will find a potentiometer that you can rotate with a small screwdriver.
Plug in the Arduino’s USB connector to power the LCD. You will see the backlight lit up. Now as you turn the knob on the potentiometer, you will start to see the first row of rectangles. If that happens, Congratulations! Your LCD is working fine.
To drive an I2C LCD you must first install a library called LiquidCrystal_I2C. This library is an enhanced version of the LiquidCrystal library that comes with your Arduino IDE.
Filter your search by typing ‘liquidcrystal‘. There should be some entries. Look for the LiquidCrystal I2C library by Frank de Brabander. Click on that entry, and then select Install.
The I2C address of your LCD depends on the manufacturer, as mentioned earlier. If your LCD has a Texas Instruments’ PCF8574 chip, its default I2C address is 0x27Hex. If your LCD has NXP Semiconductors’ PCF8574 chip, its default I2C address is 0x3FHex.
So your LCD probably has I2C address 0x27Hex or 0x3FHex. However it is recommended that you find out the actual I2C address of the LCD before using it. Luckily there’s an easy way to do this, thanks to the Nick Gammon.
But, before you proceed to upload the sketch, you need to make a small change to make it work for you. You must pass the I2C address of your LCD and the dimensions of the display to the constructor of the LiquidCrystal_I2C class. If you are using a 16×2 character LCD, pass the 16 and 2; If you’re using a 20×4 LCD, pass 20 and 4. You got the point!
First of all an object of LiquidCrystal_I2C class is created. This object takes three parameters LiquidCrystal_I2C(address, columns, rows). This is where you need to enter the address you found earlier, and the dimensions of the display.
In ‘setup’ we call three functions. The first function is init(). It initializes the LCD object. The second function is clear(). This clears the LCD screen and moves the cursor to the top left corner. And third, the backlight() function turns on the LCD backlight.
After that we set the cursor position to the third column of the first row by calling the function lcd.setCursor(2, 0). The cursor position specifies the location where you want the new text to be displayed on the LCD. The upper left corner is assumed to be col=0, row=0.
There are some useful functions you can use with LiquidCrystal_I2C objects. Some of them are listed below:lcd.home() function is used to position the cursor in the upper-left of the LCD without clearing the display.
lcd.scrollDisplayRight() function scrolls the contents of the display one space to the right. If you want the text to scroll continuously, you have to use this function inside a for loop.
lcd.scrollDisplayLeft() function scrolls the contents of the display one space to the left. Similar to above function, use this inside a for loop for continuous scrolling.
If you find the characters on the display dull and boring, you can create your own custom characters (glyphs) and symbols for your LCD. They are extremely useful when you want to display a character that is not part of the standard ASCII character set.
CGROM is used to store all permanent fonts that are displayed using their ASCII codes. For example, if we send 0x41 to the LCD, the letter ‘A’ will be printed on the display.
CGRAM is another memory used to store user defined characters. This RAM is limited to 64 bytes. For a 5×8 pixel based LCD, only 8 user-defined characters can be stored in CGRAM. And for 5×10 pixel based LCD only 4 user-defined characters can be stored.
Creating custom characters has never been easier! We have created a small application called Custom Character Generator. Can you see the blue grid below? You can click on any 5×8 pixel to set/clear that particular pixel. And as you click, the code for the character is generated next to the grid. This code can be used directly in your Arduino sketch.
After the library is included and the LCD object is created, custom character arrays are defined. The array consists of 8 bytes, each byte representing a row of a 5×8 LED matrix. In this sketch, eight custom characters have been created.
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– Arduino is an open-source platform used for building electronics projects. Arduino consists of both a physical programmable microcontroller and a piece of software, or IDE (Integrated Development Environment) that runs on your computer, used to write and upload computer code to the physical board.
– The Arduino platform unlike most previous programmable circuit boards, the Arduino does not need a separate programmer to load new code onto the board — you can simply use a USB cable. Additionally, the Arduino IDE uses a simplified version of C++, making it easier to learn to program.
– The open sources and extensible language: Arduino IDE is based on open source tool. The programming language used can be extended through the C++ library.
– The open source and expandable hardware: Arduino is based on Atmel’s ATMEGA 8-bit microcontrollers and its SAM3X8E and SAMD21 32-bit microcontrollers. Development boards and modules are planned to be released under the premise of following the “Creative Commons License Agreement”, so experienced circuit designers can make their own modules and carry out corresponding expansions and improvements. Even users who are relatively inexperienced can make a trial version of the basic Uno development board, which is easy to understand the principle of its operation and save costs.
– The Arduino hardware and software were designed for artists, designers, hobbyists, hackers, newbies, and anyone interested in creating interactive objects or environments. Arduino can interact with buttons, LEDs, motors, speakers, GPS units, cameras, the internet, and even your smart-phone or your TV.
Arduino Leonardo: Arduino’s first development board to use one microcontroller with built-in USB. It is cheaper and simpler. The code libraries allow the board to emulate a computer keyboard, mouse, and more.
LCD means liquid crystal display. Basically, any displays can be used with Arduino, including alphanumeric character LCD display, monochrome graphic LCD display, color TFT LCD display, IPS LCD display. It can also be used for non LCD displays like: PMOLED display, AMOLED display, E-ink (E-paper) displays. Orient Display developed easy interface (SPI, I2C) displays which can be easily used with Arduino.
LCD displays were first used for watches and calculators. Now, LCD display technology dominants the display world, it can be found in wearables, smart homes, mobile phones, TVs, laptops, monitors, kiosks, aircraft cockpit, digital cameras, lab instrument, power grid etc.
LCD itself can emit light itself. It has to utilize outside light sources. LCD display module normally includes LCD glass (or LCD panel), LCD driving circuitry ( can be COG, COB or TAB) and a backlight.
A LCD display 16*2 is actually a basic and simple to use LCD module. It includes LCD glass, COB (Chip on PCB Board) LCD control board, backlight, zebra to connect LCD glass and control board and a bezel to hold everything together. 16×2 LCD display can display 16 characters per line and there are two lines. Each character has 5×7 dot matrix pixels and the cursor underneath. All 16×2 LCD display originally used standard Hitachi HD44780 driver. Of course the legendary HD44780 controller had EOL long time ago. All the 16×2 LCD displays use HD44780 compatible LCD controllers. Some of them are drop replacement, some of them need to modify the initialization code a little.
Pin5 (Read/Write/Control Pin): This pin toggles the display among the read or writes operation, and it is connected to a microcontroller unit pin to get either 0 or 1 (0 = Write Operation, and 1 = Read Operation).
Pins 7-14 (Data Pins): These pins are used to send data to the display. These pins are connected in two-wire modes like 4-bit mode and 8-bit mode. In 4-wire mode, only four pins are connected to the microcontroller unit like 0 to 3, whereas in 8-wire mode, 8-pins are connected to microcontroller unit like 0 to 7.
A 16×2 LCD has two registers like data register and command register. The RS (register select) is mainly used to change from one register to another. When the register set is ‘0’, then it is known as command register. Similarly, when the register set is ‘1’, then it is known as data register.
Command Register: The main function of the command register is to store the instructions of command which are given to the display. So that predefined tasks can be performed such as clearing the display, initializing, set the cursor place, and display control. Here commands processing can occur within the register.
Data Register: The main function of the data register is to store the information which is to be exhibited on the LCD screen. Here, the ASCII value of the character is the information which is to be exhibited on the screen of LCD. Whenever we send the information to LCD, it transmits to the data register, and then the process will be starting there. When register set =1, then the data register will be selected.
The resistor in the diagram above sets the LED backlight brightness. A typical value is 220 Ohms resistor, but other values will work too. Smaller resistors will make the backlight brighter. The potentiometer is used to adjust the screen contrast. I typically use a 10K Ohm potentiometer, but other values will also work.
All of the code below uses the LiquidCrystal library that comes pre-installed with the Arduino IDE. A library is a set of functions that can be easily added to a program in an abbreviated format. In order to use a library, it needs be included in the program. Line 1 in the code below does this with the command #include
Now we’re ready to get into the programming! I’ll go over more interesting things you can do in a moment, but for now let’s just run a simple test program. This program will print “hello, world!” to the screen. Enter this code into the Arduino IDE and upload it to the board:
There are 19 different functions in the LiquidCrystal library available for us to use. These functions do things like change the position of the text, move text across the screen, or make the display turn on or off. What follows is a short description of each function, and how to use it in a program.
The LiquidCrystal() 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 number of 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:
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.
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 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 (°).
The detailed LCD tutorial can be found in the article. ARDUINO LCD SET UP AND PROGRAMMING GUIDE or to check https://github.com/arduino-libraries/LiquidCrystal
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Arduino LCD Display Modules are mostly used in embedded projects, because of its affordability and availability. The 16×2 Display LCD Module represents 16 Columns and 2 Rows. There are so many other combinations like 8×1, 8×2, 10×2, 16×1 and so on. However, 16 x 2 display LCD is most commonly used.
Arduino 16×2 LCD Display Module has 16 characters by a 2-line LCD display screen with an I2C interface. It displays 2 lines of 16 characters, white characters are displayed on a blue background.
This I2C 16×2 Arduino LCD Display Module uses the I2C communication interface. This means that we can use 4 pins for the display that is: VCC, GND, SDA, SCL. Thus, it gives us the advantage of saving 4 digital / analog pins on Arduino.
Liquid Crystal displays or LCDs have been used in electronics equipment since the late 1970s. LCD displays have the advantage of consuming very little current And they are ideal for your Arduino projects.
In this article and in the accompanying video I’ll show you how easy it is to add an LCD display to your next Arduino design. I’ll also show you a very popular Arduino Shield that has a keypad which you can use in your projects as well.
Today LCD displays are used in a variety of items from test equipment to televisions. They’re inexpensive and versatile, this makes them ideal for all sorts of designs.
LCD displays do not emit light. Instead they block the passage of light, like little windows which open and shut the let light through. The liquid crystals used inside LCD displays are sandwiched between two layers of polarized material. By changing the orientation of the liquid crystals they allow light to pass or they block the light entirely.
Because transmissive LCD displays (the type we will be using) work by blocking light they require a backlight. Several methods have been used to create back lights including electroluminescent panels and fluorescent tubes. these days the most common form of backlight is an LED, in fact so-called LED televisions are usually just LCD screens with an LED backlight system.
Another type of LCD display, the passive-matrix display, does not require a backlight, it works using reflected light. This type of display is often found in digital watches.
The principles of liquid crystals were discovered in the late 1880s but work on Modern LCD displays did not begin until the mid-1960s. a number of patents were filed in the early 1970s and in 1973 the Sharp Corporation introduced LCD displays for calculators.
The first color LCD displays were developed in the early 1980s but production units were not commonly available until the mid-1990s. By the late 1990s LCD displays were quite common.
A number of LCD displays are available for experimenters. These low-cost monochrome displays are ideal for use with microcontrollers like the Arduino and micro computers like the Raspberry Pi.
These displays are available in a number of different configurations. The part number for the display generally relates to the number of rows and columns in the display.
Common display configurations include 16 x 2, 16 x 4 and 20 x 4. All of these displays are used in a virtually identical fashion the only difference being the number of columns and rows they have.
The LCD1602 display module is a very popular and inexpensive LCD display. It is available in a number of different colors such as blue yellow and green and can easily be connected to an Arduino or Raspberry Pi.
In operation data is sent down the parallel data lines for the display. There are two types of data that can be sent to the display. The first type of data are the ASCII characters which are to be displayed on the display. The other type of data are the control characters that are used to activate the various display functions.
Brightness– This is the input for the brightness control voltage, which varies between 0 and 5 volts to control the display brightness. On some modules this pin is labeled V0.
Because the LCD module uses a parallel data input it requires 8 connections to the host microcontroller for the data alone. Add that to the other control pins and it consumes a lot of connections. On an Arduino Uno half of the I/O pins would be taken up by the display, which can be problematic if you want to use the I/O pins for other input or output devices.
We will begin our experiments by hooking up the LCD1602 to an Arduino Uno and running a few of the example sketches included with the Arduino IDE. This will allow you to get familiar with the display without needing to write any code.
We need to hookup our LCD display to our Arduino. The display can use any of the Arduino digital I/O pins as it has no special requirements, but if you hook it up as I’ve illustrated here you can run the example sketches without needing to make any modifications.
In addition to the LCD1602 display ands the Arduino Uno you will need a 10K trimpot ot potentiometer, this is used a s a brightness control for the display. You’ll also need a 220 ohm resistor to drop the voltage for the displays LED backlight.
The Arduino IDE includestheLiquidCrystallibraryand this library has a number of example sketches. I’ll go over three of them here but you can also try the other ones.
The sketch starts with a number of credits and a description of the required hardware hookup. You’ll note that this is the same hookup you just performed on your Arduino and LCD module.
We then initialize an object that we call “lcd” using the pinouts of the LCD display. If you decide to hook up your display to different pins then you’ll need to modify this section.
That ends the loop, so we start back at the top of the loop and repeat. The result will be a counter on the second line that counts seconds from the htime the Arduino was last reset.
Load the sketch up to your Arduino and observe your display. If you don’t see anything try adjusting the brightness control that you wired to the display.
The second example we will try isthe Scroll sketch. Scrolling is a useful technique when you can’t get your text to fit on one line of the LCD display.
In the loop the code demonstrates the use of thescrollDisplayLeftandscrollDisplayRightfunctions. As their names imply they move the text in a left or right direction.
Finally the last counter moves the text 16 positions to the left again, which will restore it back to the center of the display. The loop then repeats itself.
Custom characters are useful when you want to display a character that is not part of the standard 127-character ASCII character set. Thi scan be useful for creating custom displays for your project.
A character on the display is formed in a 5 x 8 matrix of blocks so you need to define your custom character within that matrix. To define the character you’ll use thecreateCharfunctionof the LiquidCrystal library. You are limited to defining a maximum of eight characters.
The Custom Character demonstration requires one additional component to be wired to the Arduino, a potentiometer (10K or greater) wired up to deliver a variable voltage to analog input pin A0.
As with the previous sketches we examined this one starts by loading theLiquidCrystallibrary and defining an object calledlcdwith the connection information for the display. It then moves on to define the custom characters.
The last two arrays,amsUpandarmsDowndefine the shape of a little “stickman”, or “stickperson” if you want to be politically correct! This is done to show how we can animate a character on the display.
Finally the setup routine ends by printing a line to the first row of the LCD display. The line makes use of two of the custom characters, the “heart” and the “smiley”.
We begin by reading the value of the voltage on pin A0 using the ArduinoanalogReadfunction. As the Arduino has a 10-bit analog to digital converter this will result in a reading ranging from 0 to 1023.
We then use an Arduinomapfunction to convert this reading into a range from 200 to 1000. This value is then assigned to an integer calleddelayTime, which as its name implies represents a time delay period.
One thing you may have noticed about using the LCD display module with the Arduino is that it consumes a lot of connections. Even in 4-wire mode there are still a total of seven connections made to the Arduino digital I/O pins. As an Arduino Uno has only 14 digital I/O pins that’s half of them used up for the display.
In other cases you would need to resort to using some of the analog pins as digital pins or even moving up to an Arduino Mega which has many more I/O pins.
But there is another solution. Use the I2C bus adapter for the LCD display and connect using I2C. This only consumes two I/O pins and they aren’t even part of the set of digital I/O pins.
The I2C or IIC bus is theInter Integrated Circuitbus. It was developed by Philips Semiconductors in 1982 for use in the television industry. The idea was to allow the integrated circuits in televisions to “talk” to one another using a standard bus.
The bus has evolved to be used as an ideal method of communicating between microcontrollers, integrated circuits, sensors and micro computers. You can use it to allow multiple Arduinos to talk to each other, to interface numerous sensors and output devices or to facilitate communications between a Raspberry Pi and one or more Arduinos.
Power– This can be either 5 Volts or 3.3 volts, depending upon the application. Note that there are many precautions that must be observed if you are interfacing a 3.3 volt and 5 volt I2C device on the same bus.
In I2C communications there is the concept of Master and Slave devices. There can be multiples of each but there can only be one Master at any given moment. In most Arduino applications one Arduino is designated Master permanently while the other Arduinos and peripherals are the Slaves.
The Master transmits the clock signal which determines how fast the data on the bus is transferred. There are several clock speeds used with the I2C bus. The original design used 100 KHz and 400 KHz clocks. Faster rates of 3.4 MHz and higher are available on some I2C configurations.
Every device on the I2C bus has a unique address. When the Master wants to communicate with a Slave device it calls the Slaves address to initiate communications.
The I2C Adapter for the LCD display is a tiny circuit board with 16 male header pins soldered to it. These pins are meant to be connected directly to the 16-pin connection on the LCD1602 display (or onto other displays that use the same connection scheme).
The device also has a 4-pin connector for connection to the I2C bus. In addition there is a small trimpot on the board, this is the LCD display brightness control.
Most of these devices have three jumpers or solder pads to set the I2C address. This may need to be changed if you are using multiple devices on the same I2C bus or if the device conflicts with another I2C device.
Most Arduino Unos also have some dedicated pins for I2C, these are internally connected to A4 and A5 and are usually located above the 14 digital I/O pins. Some models of the Uno have additional I2C connectors as well.
Note how much easier it is to use the I2C connection, which does not consume any of the Arduino Unos 14 digital I/O pins. Since A4 and A5 are being used for the I2C bus they can’t be used as analog inputs in this configuration.
Not all I2C adapters have the same I2C address, Most have address 0x20 but some use address 0x27 or 0x3F. You can change the address of your adapter by shorting some of the solder pads on the board.
Nick has written a simple I2C scanner sketch that he’s put into the public domain. It scans your I2C bus and gives you back the address of every I2C device it finds. I’ve repeated Nick’s sketch here, it’s also in the ZIP file that you can download with all of the code for this article.
Load this sketch into your Arduino then open your serial monitor. You’ll see the I2C address of your I2C LCD display adapter. You can then make note of this address and use it in the sketches we’ll be looking at now.
In order to run the subsequent sketches you’ll need to install another library. This is theNewLiquidCrystallibrarywhich, as its name implies, is an improved version of the LiquidCrystal library packaged with your Arduino IDE.
This library includes libraries for running the I2C adapter, which is why we are going to use it. But ist also can be used as a replacement for the original LiquidCrystal library and it offers improved performance over the original.
Remember that you’ll need to know the address of your I2C adapter before you run this sketch, so if you don’t know it go back and run Nick Gammon’s I2C Scanner first.
The sketch starts by loading the ArduinoWirelibrary. This is the Arduino library that facilitates communications over I2C and it’s part of your Arduino IDE installation.
On the next line we define the connections to the LCD display module from the I2C Adapter,. Note that these are NOT the connections from the Arduino, they are the connections used by the chip on the adapter itself.
In setup we set the size of the display and then print “Hello world!” on the first line in the first position. After a short delay we print “How are you?” on the second line.
Load the sketch and run it on your Arduino. If you can’t get it to work check out the address and connection information to be sure you have it right.
In this project we will put together a digital temperature and humidity gauge. It’s pretty accurate thanks to the use of a DHT22 temperature and humidity sensor. You could also substitute a cheaper DHT11 sensor but it won’t be as accurate.
We need to make a minor wiring adjustment to the hookup with our I2C adapter, specifically we will need to add a DHT22 temperature and humidity sensor into the circuit. The wiring is shown here:
As you can see the DHT22 is connected with its output tied to pin 7 of the Arduino. The other two connections are 5 volts and ground. Note that pin 3 of the DHT22 is not used.
This sketch also makes use of theDHTlibrary from Adafruit. We used this library in a previous article, “Using the HC-SR04 Ultrasonic Distance Sensor with Arduino” so you may want to take a look at that one in order to get it installed.
The key thing to note is that this library is dependant upon another Adafruit library, theirUnified Sensorlibrary. Both can be installed using the Library Manager in your Arduino IDE.
The sketch is similar to our demo sketch in that it creates an “lcd” object with the I2C and display connection information. It also defines a couple of parameters for the DHT22 sensor, as well as some floating variables to hold the temperature and humidity values.
Note that this displays the temperature in Celsius. If you want to change this to Fahrenheit its a simple matter of using some math. The formula( temp * 1.8 ) + 32will convert the results to Fahrenheit.
So far we have used the LCD1602 display module for all of our experiments. For our final demonstration we’ll switch to a popular Arduino shield that contains a LCD1602 along with some push buttons.
The LCD Keypad Shield is available from several different manufacturers. The device fits onto an Arduino Uno or an Arduino Mega and simplifies adding an LCD display to your project.
The Reset button is simply connected to the Arduino Reset pin and works just like the Reset button on the Arduino itself. This is common on many shields as the shields physically cover the Reset button.
Instead the buttons are connected to a resistor array that acts as a voltage divider. The entire array is connected to the Arduino’s analog A0 pin. One pin for five push buttons.
Note that the LCD is being used in 4-wire mode. The LCD itself is the same one used on the LCD1602 module, so all of the code for that module will work with the LCD Keypad Shield as well.
Now that you know how the LCD Keypad module works and which Arduino pins it uses all that remains is to install it onto your Arduino and load the demo sketch.
One thing – once the shield is installed on the Arduino you won’t have easy access to the unused I/O pins to connect any sensors or output devices you may want to use (although the demo sketch doesn’t need anything else connected). There are a couple of ways to get around this:
Use a shield that exposes the pins for prototyping before you install the LCD Keypad shield. In the video associated with this article I use a “Screw Shield” that brings all of the Arduino I/O pins out to a series of screw connectors. There are other similar shields. Using one of these shields is the easiest way to work with the LCD Keypad shield, as well as other Arduino shields.
The sketch begins by including theLiquidCrystallibrary. You can use the original one or the one includes with theNewLiquidCrystallibrary. We then set up an object with the LCD connections, note that these are just hard-coded as they won’t change.
Next we define a number of constants, one for each of the push buttons. Note that nothing is defined for the Reset button as it simply mimics the Arduino Reset button, however a constant is defined for the “none” condition.
After that we define a function calledread_LCD_buttons(). This function reads the value on analog port A0 and returns an integer corresponding to the button integers we defined earlier. Note that the function adds approximately 50 to each of the manufacturers specified values to account for intolerances in the resistors in the voltage divider.
We start the loop by placing the cursor 9 spaces over on the second line. We then use themillisfunction to display a counter that counts the time since the Arduino was reset. This is to test the Reset button.
We then call ourread_LCD_buttons()function and use it to display the value of the push button, right before the counter. Then we end the loop and do it again.
Load the code onto the Arduino and run it. You should see the value of each button as you press it, along with a counter that increments each second. If you press Reset the counter should reset itself back to zero.
As you can see LCD displays are pretty simple to use thanks to the availability of some excellent libraries for the Arduino. As these displays are also very inexpensive they will make an ideal addition to many of your Arduino projects.
And finally the LCD Keypad Shield is a convenient method of adding both a display and a simple keypad to your project, no wiring or soldering required.
5V DC 16 x 2 Lines ASCII Character LCD Display With Yellow Backlight Product Description: o LCD display module with Yellow Backlight o SIZE : 20x4 (2 Rows and 16 Characters Per Row) o Can display 2-lines X 16-characters o Operate with 5V DC o Wide viewing angle and high contrast o Built-in industry standard HD44780 equivalent LCD controller o Commonly Used in: Student Project, Collage,copiers, fax machines, laser printers, industrial test equipment, networking equipment such as routers and storage devices o LCM type: Characters ABOUT This is a basic 16 character by 2 line display Yellow Back light . Utilizes the extremely common HD44780 parallel interface chipset (datasheet). Interface code is freely available. You will need 7 general I/O pins(If use in 4-bit Mode) to interface to this LCD screen. Includes LED backlight. Package Contains: 1 X 16X2 LCD.
16×2 LCD is named so because; it has 16 Columns and 2 Rows. There are a lot of combinations available like, 8×1, 8×2, 10×2, 16×1, etc. But the most used one is the 16*2 LCD, hence we are using it here.
All the above mentioned LCD display will have 16 Pins and the programming approach is also the same and hence the choice is left to you. Below is the Pinout and Pin Description of 16x2 LCD Module:
These black circles consist of an interface IC and its associated components to help us use this LCD with the MCU. Because our LCD is a 16*2 Dot matrix LCD and so it will have (16*2=32) 32 characters in total and each character will be made of 5*8 Pixel Dots. A Single character with all its Pixels enabled is shown in the below picture.
So Now, we know that each character has (5*8=40) 40 Pixels and for 32 Characters we will have (32*40) 1280 Pixels. Further, the LCD should also be instructed about the Position of the Pixels.
It will be a hectic task to handle everything with the help of MCU, hence an Interface IC like HD44780 is used, which is mounted on LCD Module itself. The function of this IC is to get the Commands and Data from the MCU and process them to display meaningful information onto our LCD Screen.
The LCD can work in two different modes, namely the 4-bit mode and the 8-bit mode. In 4 bit mode we send the data nibble by nibble, first upper nibble and then lower nibble. For those of you who don’t know what a nibble is: a nibble is a group of four bits, so the lower four bits (D0-D3) of a byte form the lower nibble while the upper four bits (D4-D7) of a byte form the higher nibble. This enables us to send 8 bit data.
Now you must have guessed it, Yes 8-bit mode is faster and flawless than 4-bit mode. But the major drawback is that it needs 8 data lines connected to the microcontroller. This will make us run out of I/O pins on our MCU, so 4-bit mode is widely used. No control pins are used to set these modes. It"s just the way of programming that change.
As said, the LCD itself consists of an Interface IC. The MCU can either read or write to this interface IC. Most of the times we will be just writing to the IC, since reading will make it more complex and such scenarios are very rare. Information like position of cursor, status completion interrupts etc. can be read if required, but it is out of the scope of this tutorial.
The Interface IC present in most of the LCD is HD44780U,in order to program our LCD we should learn the complete datasheet of the IC. The datasheet is given here.
There are some preset commands instructions in LCD, which we need to send to LCD through some microcontroller. Some important command instructions are given below:
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.
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.
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.
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.
Both LCD 16x2 functions provide, and that constitute a larger disturutions for the components. While the 16x2 difference is in terms of the size of the screen,
This allows you to find some of the cheapest lcd display, cheap lcd modules, and even more per piece. Check out Alibaba.com ’ s wholesale prices to find the cheapest lcd display, cheap lcd modules, and more at wholesale prices.
When looking for lcd 16x2 for sale, it ’ s easy to bulk wholesale, browse other suppliers on Alibaba.com to discover a wide range of wholesale LCDs and 16x2 wholesale prices. For other customers, you will find an option to bulk browse at Alibaba.com.
Previous examples connect the white LED backlight to power. The following example is specifically for those using an LCD with a RGB LED backlight. The only difference between the connection is the LED"s backlight on pins 15-18.
Copy and paste the code below. Just make sure to select the correct board (in this case the Arduino/ Genuino Uno) and the COM port that the Arduino enumerated on. Then upload the code to your Arduino.
After uploading, you will notice the same "Hello, world!" and time since the Arduino was last reset in the first example. The only difference is that the current color of the backlight will be printed as it cycles through each of the primary, secondary, and tertiary colors. You should see something similar to the image below.
The previous article that you will find here included a description of the LCD display module. In it we show how to connect the screen to the Arduino UNO board and the basics of its operation with the program. Let"s admit, however, that the screen itself will not find many applications in many devices, because such a simple LCD module does not allow setting settings. A keyboard is necessary for this purpose, and although we will discuss it in more detail in one of the following articles, we will now use a ready-to-use solution from the Arduino ecosystem – Olimex-branded board under the name SHIELDLCD16x2.
222223 additional. The board has a PIC processor that communicates with the Arduino UNO through the TWI interface. Thanks to the access to the function library, handling this module with an embedded microcontroller should not cause any major problems. Let"s start with the preparation of the module for work.
Preparing the module for operation consists of two steps: hardware and software. The first one is trivial: just plug the cap into the Arduino UNO board and you"re good to go. The second, however, requires the installation of the library that contains the module"s handling functions.
To install the library, go to the website of the module manufacturer, that is, the Olimex company. Then, in the search field (next to the Search button), enter the module name part “LCD16x2” (Figure 1). Click the Search button. At the time of writing this text, the search engine will show two results: we chose “SHIELD-LCD16x2”.
Below the module description, we find the “SOFTWARE” block (Figure 2). Each line of text in this field is also a link to a file that can be downloaded from the Olimex website. At the moment we are interested in the link called “OLIMEXINO-328+SHIELD-LCD16x2 – a library and set of demo example”.
Download the ZIP file available at this link to your computer"s hard drive. Of course it is also worth taking a look at the available examples, but for our needs it is enough to install the library stored in the LCD16x2 directory.
Arduino IDE allows different ways to install libraries. In this case, the easiest way is to upload the sources to the project directory, which also includes the libraries subdirectory. The project save directory is created when installing the Arduino IDE and is usually placed by Windows (in the Polish version of the system) in the This Computer → Documents → Arduino subdirectory. To add the library sources to today"s example, simply move the LCD16x2 directory to the ibraries folder. Once this is done, we run the Arduino IDE.
Before starting work on your own program, it is worth familiarizing yourself with examples of using the functions of the LCD16x2.h library available in the Examples catalog. This is a much more effective method of learning than reading documentation, but it"s also worth remembering.
As mentioned, the shield communicates with the UNO board via a serial interface. So it"s easy to guess that the functions described in the previous article need to be modified because they used a 4-bit parallel interface. We can assume that the microcontroller in the shield board communicates in the same way with the LCD character display module, but our UNO Arduino it does not "see" the screen and control is indirect. Therefore, the program must be started by attaching the appropriate serial interface service libraries and the shield-mounted display module.
To keep things simple and not have to use the long library name, it"s worth giving it an alias lcd. We"ll use it, writing the name of the library function after the dot.
As we remember from the previous article, programs created for Arduino They are divided into two parts: the initialization function and the infinite loop. The commands of the first are entered inside the void setup() function, and the second void loop(). Commands contained within the setup function are executed only once, while inside the infinite loop – for the entire duration of the program.
The initialization function initializes the TWI interface, clears the LCD display and turns on the display backlight to full LED light intensity (parameter 0 – turns off the backlight).
If the bit is set, it is convenient to test its level using the logic product. It is only true if both are. Successive bit positions can be checked with the use of constants: 0x01 for a bit at position 0, 0x02 – at position 1, 0x04 – at position 2, 0x08 – at position 3, etc. Of course, it doesn"t matter if you use hexadecimal, binary, or decimal numbers, but with practice, hexadecimal numbers are easy to write. It can be seen that the following hexadecimal numbers used to test the bit position are powers of 2.
buttons = lcd.readButtons();if (buttons & 0x01) pressed = 1;else if (buttons & 0x02) pressed = 2;else if (buttons & 0x04) pressed = 3;else if (buttons & 0x08) pressed = 4 ;else pressed = 0;
The mask 0x01 corresponds to the first button on the left and 0x08 to the right button. The program numbered the buttons, giving the variable pressed a value corresponding to the conventional button number. Then this number is displayed on the LCD at the position starting with the first row and the first column. The message is displayed only if the value of pressed is not 0. Otherwise, the message “No button” is displayed, informing you that no button was pressed. The message ends with three spaces so that the last characters of the string are deleted when the longer "1 is pressed" overlaps.
The complete sketch is available in the materials attached to the article. We compile it and send it to the memory of the microcontroller UNO Arduino using the keyboard shortcut Ctrl+U (Sketch → Upload).
In this Instructables lesson, displaying texts and featuring them on a 16 by 2 LCD using Arduino is demonstrated. Let"s get started and I hope you enjoy!
Arduino is a device that is widely used by students for various robotics projects and sensors to detect heart-rate, temperature, air pressure ... Arduino is an open-source hardware and software company, project and user community that designs and manufactures single-board micro controllers and micro controller kits for building digital devices and interactive objects that can sense and control both physically and digitally. Basically Arduino is capable to store codes inserted from Arduino IDE using C and C++ coding languages from a computer to manipulate the functions that are assigned for the device to do. LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits. A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. The LCD has 16 pins. Starting from left to right, the first pin is GND (ground). The second pin is the VCC (5 volts) pin which is connected to the Arduino board. The third pin is the Vo (display contrast) pin which can be connected to a potentiometer to adjust the display contrast. Fourth pin is the RS (register select) pin used for selecting the commands/data sent to the LCD using methods defined in the Arduino Liquid Crystal packages. Fifth one is the R/W (read/write) pin which selects the mode whether we read or write on the LCD. Sixth pin is the E (enable) pin which enables writings to the registers. The next 8 pins are data pins D0 to D7 that registers are written in using binary numbers according to the ASCII Table. The fifteenth pin is the A (anode) , and the last one is K (cathode).
The IDE Now that we have a little undrestanding of what Arduino and the LCD are, let"s jump ahead into the Arduino IDE and install that on our computer. Arduino IDE can be downloaded from Or from the windows store on windows 8. The IDE is the place where coding takes place. Here, the codes are written in C and C++. After compiling the code and troubleshooting the mistakes, the complied code is sent to the Arduino Board using the USB 2 cable. After installing the IDE we implement the Liquid Crystal package as shown below. Liquid Crystal Package implementation... Installing LiquidCrystal package opens our access to use the methods and implementations defined in the specific package regarding to the LCD on our IDE to be compiled and stored into the Arduino board. After package installation, the setup and loop are written in the IDE. Follow the above and copy the parameters to make a connection between the board and the LCD.
Compiling and Storing the Code into the Arduino For the last step, connect the Arduino to the computer using a USB-2 cable. compile the code and select the Arduino UNO on the IDE