best arduino lcd display free sample
Adding a display to your Arduino can serve many purposes. Since a common use for microcontrollers is reading data from sensors, a display allows you to see this data in real-time without needing to use the serial monitor within the Arduino IDE. It also allows you to give your projects a personal touch with text, images, or even interactivity through a touch screen.
Transparent Organic Light Emitting Diode (TOLED) is a type of LED that, as you can guess, has a transparent screen. It builds on the now common OLED screens found in smartphones and TVs, but with a transparent display, offers up some new possibilities for Arduino screens.
Take for example this brilliant project that makes use of TOLED displays. By stacking 10 transparent OLED screens in parallel, creator Sean Hodgins has converted a handful of 2D screens into a solid-state volumetric display. This kind of display creates an image that has 3-dimensional depth, taking us one step closer to the neon, holographic screens we imagine in the future.
Crystalfontz has a tiny monochrome (light blue) 1.51" TOLED that has 128x56 pixels. As the technology is more recent than the following displays in this list, the cost is higher too. One of these screens can be purchased for around $26, but for certain applications, it might just be worth it.
The liquid crystal display (LCD) is the most common display to find in DIY projects and home appliances alike. This is no surprise as they are simple to operate, low-powered, and incredibly cheap.
This type of display can vary in design. Some are larger, with more character spaces and rows; some come with a backlight. Most attach directly to the board through 8 or 12 connections to the Arduino pins, making them incompatible with boards with fewer pins available. In this instance, buy a screen with an I2C adapter, allowing control using only four pins.
Available for only a few dollars (or as little as a couple of dollars on AliExpress with included I2C adapter), these simple displays can be used to give real-time feedback to any project.
The screens are capable of a large variety of preset characters which cover most use cases in a variety of languages. You can control your LCD using the Liquid Crystal Library provided by Arduino. The display() and noDisplay() methods write to the LCD, as shown in the official tutorial on the Arduino website.
Are you looking for something simple to display numbers and a few basic characters? Maybe you are looking for something with that old-school arcade feel? A seven-segment display might suit your needs.
These simple boards are made up of 7 LEDs (8 if you include the dot), and work much like normal LEDs with a common Anode or Cathode connection. This allows them to take one connection to V+ (or GND for common cathode) and be controlled from the pins of your Arduino. By combining these pins in code, you can create numbers and several letters, along with more abstract designs—anything you can dream up using the segments available!
Next on our list is the 5110 display, also affectionately known as the Nokia display due to its wide use in the beloved and nigh indestructible Nokia 3310.
These tiny LCD screens are monochrome and have a screen size of 84 x 48 pixels, but don"t let that fool you. Coming in at around $2 on AliExpress, these displays are incredibly cheap and usually come with a backlight as standard.
Depending on which library you use, the screen can display multiple lines of text in various fonts. It"s also capable of displaying images, and there is free software designed to help get your creations on screen. While the refresh rate is too slow for detailed animations, these screens are hardy enough to be included in long-term, always-on projects.
For a step up in resolution and functionality, an OLED display might be what you are looking for. At first glance, these screens look similar to the 5110 screens, but they are a significant upgrade. The standard 0.96" screens are 128 x 64 monochrome, and come with a backlight as standard.
They connect to your Arduino using I2C, meaning that alongside the V+ and GND pins, only two further pins are required to communicate with the screen. With various sizes and full color options available, these displays are incredibly versatile.
For a project to get you started with OLED displays, our Electronic D20 build will teach you everything you need to know -- and you"ll end up with the ultimate geeky digital dice for your gaming sessions!
These displays can be used in the same way as the others we have mentioned so far, but their refresh rate allows for much more ambitious projects. The basic monochrome screen is available on Amazon.
Thin-film-transistor liquid-crystal displays (TFT LCDs) are in many ways another step up in quality when it comes to options for adding a screen to your Arduino. Available with or without touchscreen functionality, they also add the ability to load bitmap files from an on-board microSD card slot.
Arduino have an official guide for setting up their non-touchscreen TFT LCD screen. For a video tutorial teaching you the basics of setting up the touchscreen version, YouTuber educ8s.tv has you covered:
With the touchscreen editions of these screens costing less than $10 on AliExpress, these displays are another great choice for when you need a nice-looking display for your project.
Looking for something a little different? An E-paper (or E-ink depending on who you ask) display might be right for you. These screens differ from the others giving a much more natural reading experience, it is no surprise that this technology is the cornerstone of almost every e-reader available.
The reason these displays look so good is down to the way they function. Each "pixel" contains charged particles between two electrodes. By switching the charge of each electrode, you can influence the negatively charged black particles to swap places with the positively charged white particles.
This is what gives e-paper such a natural feel. As a bonus, once the ink is moved to its location, it uses no power to keep it there. This makes these displays naturally low-power to operate.
This article has covered most options available for Arduino displays, though there are definitely more weird and wonderful ways to add feedback to your DIY devices.
Now that you have an idea of what is out there, why not incorporate a screen into your DIY smart home setup? If retro gaming is more your thing, why not create some retro games on Arduino?
The Arduino board has a wide variety of compatible displays that you can use in your electronic projects. In most projects, it’s very useful to give the user some sort of feedback from the Arduino.
With the TFT display you can display colorful images or graphics. This module has a resolution of 480 x 320. This module includes the SD card socket and SPI FLASH circuit.
This is a tiny display with just 1 x 0.96 Inch. This display has a black background, and displays characters in white. There are other similar displays that can show the characters in other colors.
This article shows how to use the SSD1306 0.96 inch I2C OLED display with the Arduino. We’ll show you some features of the OLED display, how to connect it to the Arduino board, and how to write text, draw shapes and display bitmap images. Lastly, we’ll build a project example that displays temperature and humidity readings.
The organic light-emitting diode(OLED) display that we’ll use in this tutorial is the SSD1306 model: a monocolor, 0.96-inch display with 128×64 pixels as shown in the following figure.
The OLED display doesn’t require backlight, which results in a very nice contrast in dark environments. Additionally, its pixels consume energy only when they are on, so the OLED display consumes less power when compared with other displays.
The model we’re using here has only four pins and communicates with the Arduino using I2C communication protocol. There are models that come with an extra RESET pin. There are also other OLED displays that communicate using SPI communication.
Because the OLED display uses I2C communication protocol, wiring is very simple. You just need to connect to the Arduino Uno I2C pins as shown in the table below.
To control the OLED display you need the adafruit_SSD1306.h and the adafruit_GFX.h libraries. Follow the next instructions to install those libraries.
After wiring the OLED display to the Arduino and installing all required libraries, you can use one example from the library to see if everything is working properly.
The Adafruit library for the OLED display comes with several functions to write text. In this section, you’ll learn how to write and scroll text using the library functions.
First, you need to import the necessary libraries. The Wire library to use I2C and the Adafruit libraries to write to the display: Adafruit_GFX and Adafruit_SSD1306.
Then, you define your OLED width and height. In this example, we’re using a 128×64 OLED display. If you’re using other sizes, you can change that in the SCREEN_WIDTH, and SCREEN_HEIGHT variables.
The (-1) parameter means that your OLED display doesn’t have a RESET pin. If your OLED display does have a RESET pin, it should be connected to a GPIO. In that case, you should pass the GPIO number as a parameter.
To draw a pixel in the OLED display, you can use the drawPixel(x, y, color) method that accepts as arguments the x and y coordinates where the pixel appears, and color. For example:
The library also provides methods to displays rectangles with round corners: drawRoundRect() and fillRoundRect(). These methods accepts the same arguments as previous methods plus the radius of the corner. For example:
The library provides an additional method that you can use with shapes or text: the invertDisplay() method. Pass true as argument to invert the colors of the screen or false to get back to the original colors.
Copy your array to the sketch. Then, to display the array, use the drawBitmap() method that accepts the following arguments (x, y, image array, image width, image height, rotation). The (x, y) coordinates define where the image starts to be displayed.
In this section we’ll build a project that displays temperature and humidity readings on the OLED display. We’ll get temperature and humidity using the DHT11 temperature and humidity sensor. If you’re not familiar with the DHT11 sensor, read the following article:
The code starts by including the necessary libraries. The Wire, Adafruit_GFX and Adafruit_SSD1306 are used to interface with the OLED display. The Adafruit_Sensor and the DHT libraries are used to interface with the DHT22 or DHT11 sensors.
The (-1) parameter means that your OLED display doesn’t have a RESET pin. If your OLED display does have a RESET pin, it should be connected to a GPIO. In that case, you should pass the GPIO number as a parameter.
In this case, the address of the OLED display we’re using is 0x3C. If this address doesn’t work, you can run an I2C scanner sketch to find your OLED address. You can find the I2C scanner sketch here.
We use the setTextSize() method to define the font size, the setCursor() sets where the text should start being displayed and the print() method is used to write something on the display.
After wiring the circuit and uploading the code, the OLED display shows the temperature and humidity readings. The sensor readings are updated every five seconds.
The I2C address for the OLED display we are using is 0x3C. However, yours may be different. So, make sure you check your display I2C address using an I2C scanner sketch.
The OLED display provides an easy and inexpensive way to display text or graphics using an Arduino. We hope you’ve found this guide and the project example useful.
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.
Before installing LiquidCrystal_I2C, remove any other libraries that may reside in the Arduino IDE with the same LiquidCrystal_I2C name. Doing this will ensure that only the known good library is in use. LiquidCrystal_I2C works in combination with the preinstalled Wire.h library in the Arduino editor.
To install the LiquidCrystal_I2C library, use the SketchSketch > Include Library > Add .ZIP Library…from the Arduino IDE (see example). Point to the LiquidCrystal_I2C-master.zip which you previously downloaded and the Library will be installed and set up for use.
Several examples and code are included in the Library installation, which can provide some reference and programming examples. You can use these example sketches as a basis for developing your own code for the LCD display module.
There may be situations where you should uninstall the Arduino IDE. The reason for this could be due to Library conflicts or other configuration issues. There are a few simple steps to uninstalling the IDE.
The I2c address can be changed by shorting the address solder pads on the I2C module. You will need to know the actual address of the LCD before you can start using it.
Once you have the LCD connected and have determined the I2C address, you can proceed to write code to display on the screen. The code segment below is a complete sketch ready for downloading to your Arduino.
The code assumes the I2C address of the LCD screen is at 0x27 and can be adjusted on the LiquidCrystal_I2C lcd = LiquidCrystal_I2C(0x27,16,2); as required.
Similar to the cursor() function, this will create a block-style cursor. Displayed at the position of the next character to be printed and displays as a blinking rectangle.
This function turns off any characters displayed to the LCD. The text will not be cleared from the LCD memory; rather, it is turned off. The LCD will show the screen again when display() is executed.
Scrolling text if you want to print more than 16 or 20 characters in one line then the scrolling text function is convenient. First, the substring with the maximum of characters per line is printed, moving the start column from right to left on the LCD screen. Then the first character is dropped, and the next character is displayed to the substring. This process repeats until the full string has been displayed on the screen.
The LCD driver backpack has an exciting additional feature allowing you to create custom characters (glyph) for use on the screen. Your custom characters work with both the 16×2 and 20×4 LCD units.
A custom character allows you to display any pattern of dots on a 5×8 matrix which makes up each character. You have full control of the design to be displayed.
To aid in creating your custom characters, there are a number of useful tools available on Internet. Here is a LCD Custom Character Generator which we have used.
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.
I hope you enjoyed this tutorial and learned something new. Feel free to ask any question in the comments section below and don’t forget to check out my full collection of 30+ Arduino Projects.
The LiquidCrystal Library is the key to easily using LCDs with Arduino. What is great is that it comes preinstalled with your Arduino software – so you don’t have to download anything special to make it work.
The library is chock full of handy functions; functions for scrolling text to blinking the LCD screen – and pretty much everything in between. You will quickly find out that understanding how the cursor works is vital to controlling the display properly.
My favorite page on the Arduino website is the reference page – this is where all the functions are explained in detail. Libraries also have reference pages, and the LiquidCrystal Library is no exception.
You will find every available function listed, each hyperlinked to a page that describes the parameters of each. You may find that parameters alone are not sufficient to grasp the “concept” of the functions – which is what I will do my best to explain here.
Better yet for this library, it also includes several examples which you can reference to get a feel how the creators of the library implemented specific functions in their sketch. You can open up the sketches directly in your Arduino IDE by going to File > Examples > LiquidCrystal.
But don’t worry if this makes no sense to you right now – it didn’t make sense to me for a long time. The point of this tutorial is to get your LCD up and running – so don’t sweat the small stuff, just include the #include .
For example, a “car” object might have the data (color, model, year) associated with it. It would also have some functionality, maybe like drive(), stop(), honk(). When we declare the LiquidCrystal object, we simply write the type of object, which is LiquidCrystal – followed by a space and name the object. Here we are naming it “lcd”. You could name it mamaJama if you wanted – it doesn’t matter.
Finally, you pass it some data using the parenthesis. The numbers in the parentheses tell the new object which Arduino pins to associate with it. As long as we have our pins connected to the LCD correctly, all the work of handling the pin assignments is taken care of behind the scenes.
When we start using the functions for this object, we will preface each one with the name of the object. So in this example we named it “lcd”. So when we use the blink() function from the LiquidCrystal library, we would write:
So let’s sum this up – and remember understanding this in minute detail is not that important for getting your LCD up and running – the details will fill in with time. If you want results – just include this at the top if your sketch:
We use the begin() function from the library to pass the LiquidCrystal object the size of the LCD. The format is (COLUMNS, ROWS). Here I am using a 16 Column by 2 Row LCD screen, hence lcd.begin(16,2). Remeber, if you are using a name other than lcd, it would be:
What is awesome about the LiquidCrystal library is that it will support all types of LCD screen sizes – and the only thing you have to change is the numbers you pass in the begin() function. Now let’s move on to some important aspects of using the LiquidCrystal library – namely, understanding indexing.
Not surprisingly, this will display the words “hello, world!” on the LCD screen. Now recall that setup() only runs once – but the text “hello, world!” will stay up on your LCD screen. This is a really handy feature of LCDs – the text you print is “sticky” – that is, unless you need to change the text or the location of the text on the screen, then there is no need to continually update it in the sketch.
Yes – I know – the zero indexing takes some time to get used to – but if you remember to subtract one from the physical location of the column and row, it will give you the index location. So why do we care about the location of the cursor? The location of the cursor determines where text will be displayed on the screen. So if we use this combination in the loop():
Sometimes you will not want anything at all to show on your LCD display or you might want it go into a sleep mode. It is simple to do this using the noDisplay() and display() functions.
This code will turn on and off the display every half second. An important thing to note is that the previous text is maintained on the screen even after it has been turned off and turned back on.
This library enables you to use Hardware-based PWM channels on Arduino AVR ATtiny-based boards (ATtiny3217, etc.), using megaTinyCore, to create and output PWM to pins.
This library enables you to use ISR-based PWM channels on Arduino AVR ATtiny-based boards (ATtiny3217, etc.), using megaTinyCore, to create and output PWM any GPIO pin.
Small low-level classes and functions for Arduino: incrementMod(), decToBcd(). strcmp_PP(), PrintStr, PrintStrN, printPad{N}To(), printIntAsFloat(), TimingStats, formUrlEncode(), FCString, KString, hashDjb2(), binarySearch(), linearSearch(), isSorted(), reverse(), and so on.
Cyclic Redundancy Check (CRC) algorithms (crc8, crc16ccitt, crc32) programmatically converted from C99 code generated by pycrc (https://pycrc.org) to Arduino C++ using namespaces and PROGMEM flash memory.
Various sorting algorithms for Arduino, including Bubble Sort, Insertion Sort, Selection Sort, Shell Sort (3 versions), Comb Sort (4 versions), Quick Sort (3 versions).
Date, time, timezone classes for Arduino supporting the full IANA TZ Database to convert epoch seconds to date and time components in different time zones.
Clock classes for Arduino that provides an auto-incrementing count of seconds since a known epoch which can be synchronized from external sources such as an NTP server, a DS3231 RTC chip, or an STM32 RTC chip.
Useful Arduino utilities which are too small as separate libraries, but complex enough to be shared among multiple projects, and often have external dependencies to other libraries.
Fast and compact software I2C implementations (SimpleWireInterface, SimpleWireFastInterface) on Arduino platforms. Also provides adapter classes to allow the use of third party I2C libraries using the same API.
Enables Bluetooth® Low Energy connectivity on the Arduino MKR WiFi 1010, Arduino UNO WiFi Rev.2, Arduino Nano 33 IoT, Arduino Nano 33 BLE and Nicla Sense ME.
Fully Asynchronous UDP Library for RASPBERRY_PI_PICO_W using CYW43439 WiFi with arduino-pico core. The library is easy to use and includes support for Unicast, Broadcast and Multicast environments.
The last hope for the desperate AVR programmer. A small (344 bytes) Arduino library to have real program traces and to find the place where your program hangs.
An Arduino library that takes input in degrees and output a string or integer for the 4, 8, 16, or 32 compass headings (like North, South, East, and West).
Directly interface Arduino, esp8266, and esp32 to DSC PowerSeries and Classic security systems for integration with home automation, remote control apps, notifications on alarm events, and emulating DSC panels to connect DSC keypads.
This library enables you to use Hardware-based PWM channels on Arduino AVRDx-based boards (AVR128Dx, AVR64Dx, AVR32Dx, etc.), using DxCore, to create and output PWM.
This library enables you to use ISR-based PWM channels on Arduino AVRDx-based boards (AVR128Dx, AVR64Dx, AVR32Dx, etc.), using DxCore, to create and output PWM any GPIO pin.
Small and easy to use Arduino library for using push buttons at INT0/pin2 and / or any PinChangeInterrupt pin.Functions for long and double press detection are included.Just connect buttons between ground and any pin of your Arduino - that"s itNo call of begin() or polling function like update() required. No blocking debouncing delay.
Arduino library for controlling standard LEDs in an easy way. EasyLed provides simple logical methods like led.on(), led.toggle(), led.flash(), led.isOff() and more.
OpenTherm Library to control Central Heating (CH), HVAC (Heating, Ventilation, Air Conditioning) or Solar systems by creating a thermostat using Arduino IDE and ESP32 / ESP8266 hardware.
An ESP8266/ESP32-AT library for Arduino providing an easy-to-use way to control ESP8266-AT/ESP32-AT WiFi shields using AT-commands. For AVR, Teensy, SAM DUE, SAMD21, SAMD51, STM32, nRF52, SIPEED_MAIX_DUINO and RP2040-based (Nano_RP2040_Connect, RASPBERRY_PI_PICO, etc.) boards using ESP8266/ESP32 AT-command shields.
ezTime - pronounced "Easy Time" - is a very easy to use Arduino time and date library that provides NTP network time lookups, extensive timezone support, formatted time and date strings, user events, millisecond precision and more.
A library for implementing fixed-point in-place Fast Fourier Transform on Arduino. It sacrifices precision and instead it is way faster than floating-point implementations.
The GCodeParser library is a lightweight G-Code parser for the Arduino using only a single character buffer to first collect a line of code (also called a "block") from a serial or file input and then parse that line into a code block and comments.
Arduino library for the Flysky/Turnigy RC iBUS protocol - servo (receive) and sensors/telemetry (send) using hardware UART (AVR, ESP32 and STM32 architectures)
An Arduino library to control the Iowa Scaled Engineering I2C-IRSENSE ( https://www.iascaled.com/store/I2C-IRSENSE ) reflective infrared proximity sensor.
Convinient way to map a push-button to a keyboard key. This library utilize the ability of 32u4-based Arduino-compatible boards to emulate USB-keyboard.
This library allows you to easily create light animations from an Arduino board or an ATtiny microcontroller (traffic lights, chaser, shopkeeper sign, etc.)
LiquidCrystal fork for displays based on HD44780. Uses the IOAbstraction library to work with i2c, PCF8574, MCP23017, Shift registers, Arduino pins and ports interchangably.
This library enables you to use ISR-based PWM channels on RP2040-based boards, such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, with Arduino-mbed (mbed_nano or mbed_rp2040) core to create and output PWM any GPIO pin.
Arduino library for MCP4728 quad channel, 12-bit voltage output Digital-to-Analog Convertor with non-volatile memory and I2C compatible Serial Interface
This library enables you to use ISR-based PWM channels on an Arduino megaAVR board, such as UNO WiFi Rev2, AVR_Nano_Every, etc., to create and output PWM any GPIO pin.
Replace Arduino methods with mocked versions and let you develop code without the hardware. Run parallel hardware and system development for greater efficiency.
A library package for ARDUINO acting as ModBus slave communicating through UART-to-RS485 converter. Originally written by Geabong github user. Improved by Łukasz Ślusarczyk.
This library enables you to use ISR-based PWM channels on an nRF52-based board using Arduino-mbed mbed_nano core such as Nano-33-BLE to create and output PWM any GPIO pin.
This library enables you to use ISR-based PWM channels on an nRF52-based board using Adafruit_nRF52_Arduino core such as Itsy-Bitsy nRF52840 to create and output PWM any GPIO pin.
An Arduino library for the Nano 33 BLE Sense that leverages Mbed OS to automatically place sensor measurements in a ring buffer that can be integrated into programs in a simple manner.
his library enables you to use Hardware-based PWM channels on RP2040-based boards, such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, with either Arduino-mbed (mbed_nano or mbed_rp2040) or arduino-pico core to create and output PWM to any GPIO pin.
This library enables you to use SPI SD cards with RP2040-based boards such as Nano_RP2040_Connect, RASPBERRY_PI_PICO using either RP2040 Arduino-mbed or arduino-pico core.
This library enables you to use ISR-based PWM channels on RP2040-based boards, such as ADAFRUIT_FEATHER_RP2040, RASPBERRY_PI_PICO, etc., with arduino-pico core to create and output PWM any GPIO pin.
The most powerful and popular available library for using 7/14/16 segment display, supporting daisy chaining so you can control mass amounts from your Arduino!
Enables smooth servo movement. Linear as well as other (Cubic, Circular, Bounce, etc.) ease movements for servos are provided. The Arduino Servo library or PCA9685 servo expanders are supported.
Enables reading and writing on SD card using SD card slot connected to the SDIO/SDMMC-hardware of the STM32 MCU. For slots connected to SPI-hardware use the standard Arduino SD library.
Menu library for Arduino with IoT capabilities that supports many input and display devices with a designer UI, code generator, CLI, and strong remote control capability.
A library for creating Tickers which can call repeating functions. Replaces delay() with non-blocking functions. Recommanded for ESP and Arduino boards with mbed behind.
This library enables you to use Interrupt from Hardware Timers on an Arduino, Adafruit or Sparkfun AVR board, such as Nano, UNO, Mega, Leonardo, YUN, Teensy, Feather_32u4, Feather_328P, Pro Micro, etc.
This library enables you to use Interrupt from Hardware Timers on supported Arduino boards such as AVR, Mega-AVR, ESP8266, ESP32, SAMD, SAM DUE, nRF52, STM32F/L/H/G/WB/MP1, Teensy, Nano-33-BLE, RP2040-based boards, etc.
A simple library to display numbers, text and animation on 4 and 6 digit 7-segment TM1637 based display modules. Offers non-blocking animations and scrolling!
Really tiny library to basic RTC functionality on Arduino. DS1307, DS3231 and DS3232 RTCs are supported. See https://github.com/Naguissa/uEEPROMLib for EEPROM support. Temperature, Alarms, SQWG, Power lost and RAM support.
Monochrome LCD, OLED and eInk Library. Display controller: SSD1305, SSD1306, SSD1309, SSD1312, SSD1316, SSD1318, SSD1320, SSD1322, SSD1325, SSD1327, SSD1329, SSD1606, SSD1607, SH1106, SH1107, SH1108, SH1122, T6963, RA8835, LC7981, PCD8544, PCF8812, HX1230, UC1601, UC1604, UC1608, UC1610, UC1611, UC1617, UC1638, UC1701, ST7511, ST7528, ST7565, ST7567, ST7571, ST7586, ST7588, ST75160, ST75256, ST75320, NT7534, ST7920, IST3020, IST3088, IST7920, LD7032, KS0108, KS0713, HD44102, T7932, SED1520, SBN1661, IL3820, MAX7219, GP1287, GP1247, GU800. Interfaces: I2C, SPI, Parallel.
True color TFT and OLED library, Up to 18 Bit color depth. Supported display controller: ST7735, ILI9163, ILI9325, ILI9341, ILI9486,LD50T6160, PCF8833, SEPS225, SSD1331, SSD1351, HX8352C.
RFC6455-based WebSockets Server and Client for Arduino boards, such as nRF52, Portenta_H7, SAMD21, SAMD51, STM32F/L/H/G/WB/MP1, Teensy, SAM DUE, RP2040-based boards, besides ESP8266/ESP32 (ESP32, ESP32_S2, ESP32_S3 and ESP32_C3) and WT32_ETH01. Ethernet shields W5100, W5200, W5500, ENC28J60, Teensy 4.1 NativeEthernet/QNEthernet or Portenta_H7 WiFi/Ethernet. Supporting websocket only mode for Socket.IO. Ethernet_Generic library is used as default for W5x00. Now supporting RP2040W
Enables network connection (local and Internet) and WiFiStorage for SAM DUE, SAMD21, SAMD51, Teensy, AVR (328P, 32u4, 16u4, etc.), Mega, STM32F/L/H/G/WB/MP1, nRF52, NINA_B302_ublox, NINA_B112_ublox, RP2040-based boards, etc. in addition to Arduino MKR WiFi 1010, Arduino MKR VIDOR 4000, Arduino UNO WiFi Rev.2, Nano 33 IoT, Nano RP2040 Connect. Now with fix of severe limitation to permit sending much larger data than total 4K and using new WiFi101_Generic library
Universal Timer with 1 millisecond resolution, based on system uptime (i.e. Arduino: millis() function or STM32: HAL_GetTick() function), supporting OOP principles.
An LCD display (Liquid Crystal Display) is a flat panel display that uses the light modulating properties of liquid crystals. Since liquid crystals do not emit light, this type of display needs a backlight, or external light to produce an image. That’s why the power consumption of these displays is relatively high for battery powered Arduino projects.
On the other hand, the price of the LCDs is very low. The Nokia 5110, the 1.8″ Color TFT display and the 3.5″ Color TFT display, are all displays that use the LCD technology.
An OLED display is a screen that uses organic light emitting diodes. It requires no backlight, so the power consumption of these display is low and depends on how many pixels are lit. Also, since the screen does not need a backlight, it can display deep black color. Another advantage of this kind of display is that they are usually thinner and lighter the LCD displays. In low light, OLED displays can achieve better contrast in comparison to LCDs.
On the other hand, OLED displays are more expensive than LCD displays. Because of this, the available OLED displays for Arduino are tiny in size, and until recently they were only monochrome. A few months ago a small Color OLED appeared at a relatively low cost.
E-Paper of Electronic paper are displays that unlike traditional LCD or OLED displays does not emit light but reflect light. It is like the ink on the paper. This characteristic makes e-paper displays very comfortable to read, and they have an excellent readability under direct sunlight. Another great thing about e-paper displays is that they can hold static text and image for months without electricity! Yes, that’s correct, the display can show text and image even if it is off! That makes e-paper displays ideal for low powered projects!
Unfortunately there some disadvantages as well. The price of e-paper display is still very high. For example, this 4.3″ E-Paper display for Arduino costs over $60. Another significant disadvantage is that e-paper displays take a lot of time to update, as much as 2-3 seconds. So, they are only helpful for static text and images and not animations.
The Nokia 5110 is a basic graphic LCD screen which was originally intended for as a cell phone screen. It uses the PCD8544 controller which is a low power CMOS LCD controller/driver. Because of this, this display has an impressive power consumption. It uses only 0.4mA when it is on, but the backlight is disabled. It uses less than 0.06mA when in sleep mode! That’s one of the reasons that make this display my favorite. The PCD8544 interfaces to microcontrollers through a serial bus interface. That makes the display very easy to use with Arduino.
This impressive library is developed by Henning Karlsen who has put an enormous amount of effort to help the Arduino community move forward with his libraries. I have prepared a detailed tutorial on how to use the Nokia 5110 LCD display with Arduino. You watch it in this video:
This is a very new display, and it quickly became one of my favorites, because it uses the OLED technology, it can display 65.000 colors, it is very small, very bright and it has low power consumption.
Furthermore, it is also straightforward to use with Arduino since there is a library for it. It is the Adafruit SSD1331 library, and you find it here.
Also, despite the fact that this display is tiny, it is one of my favorites because it is ideal for handheld projects. Its power consumption is around 10-20 mA, and it depends on how many pixels are lit.
First of all the ST7735 Color TFT display is a very inexpensive display. It costs around $5, and it has a great library support. I have used it many of my projects, and I think it is great!
Furthermore, the display offers a resolution of 160×128 pixels, and it can display 65.000 colors. It uses the SPI interface to communicate with the Arduino boards. In addition to that, it works well with all the available Arduino boards, like the Arduino Uno, the Arduino Mega, and the Arduino Due. It also works fine with ESP8266 based boards, like the Wemos D1 and the Wemos D1 mini board.
In conclusion, this is one of the best Arduino displays if you need color and low cost. I have prepared a detailed tutorial about the 1.8″ ST7735 Color TFT display, you can watch it here:
This is another very nice display to use with Arduino. It is an OLED display and that means that it has a low power consumption. The power consumption of this display is around 10-20 mA and it depends on how many pixels are lit.
The display has a resolution of 128×64 pixels and it is tiny in size. Furthermore, it is very bright, and it has a great library support. Adafruit has developed a very nice library about this display, and you can find this library here.
In addition to that, the display uses the I2C interface, so the connection with Arduino is incredibly easy. You only need to connect two wires except for Vcc and GND. If you are new to Arduino and you want an inexpensive and easy to use display to use with your project, start with display. It is the easiest way to add a display to your Arduino project.
This 3.5″ Color TFT display is the biggest display that you can use in your project if you are using an Arduino Uno or a Mega. Unfortunately, it does not support the fast Arduino Due, nor the Wemos D1 ESP8266 board.
One of the biggest advantages of this display except it big size is its impressive resolution. The resolution of the display is 480×320 pixels! In addition to that, the display offers an SD card reader at the back so that you can store data.
Also, the display comes as a shield. So, you only have to connect the display with your Arduino board, and you are ready to use it. Of course, you need to install the appropriate driver for the display. Luckily I have a link to this driver here. Search for the download file, and you will find the library for the display in that .zip file.
In conlcusion, this display is a very easy to use display and it is ideal for beginners. Additionally you can use this display if you want to add a big display in your project. If fast refresh rate is not a requirement of your project, this display is a great display to use!
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:
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 lets 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.
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 (°):
In this chapter, you learn how to connect an LCD to your Arduino, and you learn how to use the Arduino LiquidCrystal library to write text and arbitrary custom characters to your LCD. After you have the basics down, you add some components to make a simple thermostat capable of obtaining local temperature data, reporting it to you, and controlling a fan to compensate for heat. An LCD will give you live information, a speaker will alert you when the temperature is getting too hot, and the fan will turn on to automatically cool you down.
To complete the examples in this chapter, we use a parallel LCD screen. These are extremely common and come in all kinds of shapes and sizes. The most common is a 16×2 character display with a single row of 16 pins (14 if it does not have a backlight). In this chapter, we use a 16-pin LCD display that can show a total of 32 characters (16 columns and 2 rows).
If your display didn’t come with a 16-pin header already soldered on, you need to solder one on so that you can easily install it in your breadboard. With the header successfully soldered on, your LCD should look like the one shown in Figure 3-1, and you can insert it into your breadboard.
Next, you wire up your LCD to a breadboard and to your Arduino. All of these parallel LCD modules have the same pin-out and can be wired in one of two modes: 4-pin or 8-pin mode. You can accomplish everything you might want to do using just 4 pins for communication; that’s how you’ll wire it up. There are also pins for enabling the display, setting the display to command mode or character mode, and for setting it to read/write mode. Table 3-1 describes all of these pins.
The register selection pin sets the LCD to command or character mode, so it knows how to interpret the next set of data that is transmitted via the data lines. Based on the state of this pin, data sent to the LCD is either interpreted as a command (for example, move the cursor) or characters (for example, the letter a).
You can illuminate the backlight by connecting the anode pin to 5V and the cathode pin to ground if you are using an LCD with a built-in resistor for the backlight. If you are not, you must put a current-limiting resistor in-line with the anode or cathode pin. The datasheet for your device will generally tell you if you need to do this.
Now your LCD is ready for action! Once you get the code loaded in the next section, you can start displaying text on the screen. The potentiometer will adjust the contrast between the text and the background color of the screen.
The Arduino IDE includes the LiquidCrystal library, a set of functions that makes it very easy to interface with the parallel LCD that you are using. The LiquidCrystal library has an impressive amount of functionality, including blinking the cursor, automatically scrolling text, creating custom characters, and changing the direction of text printing. This chapter does not cover every function, but instead gives you the tools you need to understand to interface with the display using the most important functions. You can find descriptions of the library functions and examples illustrating their use on the Arduino website:
In this first example, we add some text and an incrementing number to the display. This exercise demonstrates how to initialize the display, how to write text, and how to move the cursor. First, include the LiquidCrystal library:
The arguments for the LCD initialization represent the Arduino pins connected to RS, EN, D4, D5, D6, and D7, in that order. In the setup, you call the library’s begin() function to set up the LCD display with the character size.
(The one we are using is a 16×2 display, but you might be using another size, such as a 20×4). The arguments for this command represent the number of columns and the number of rows, respectively:
After doing that, you can call the library’s print() and setCursor()commands to print text to a given location on the display. For example, if you want to print your name on the second line, you issue these commands:
WARNING: The library does not check for strings that are too long. So, if youtry to print a string starting at position 0 that is longer than the number of charactersin the row you are addressing, you might notice strange behavior. Make sureto check that whatever you are printing will fit on the display!
Using this knowledge, we can now write a simple program that displays some text on the first row and that prints a counter that increments once every second on the second row. Listing 3-1 shows the complete program to accomplish this. Load it on to your Arduino and confirm that it works as expected. If you don’t see anything, adjust the contrast with the potentiometer.
This program combines all the steps that you learned about earlier. The library is first included at the top of the program. A time variable is initialized to 0, so that it can be incremented once per second during theloop(). A LiquidCrysal object called lcd is created with the proper pins assigned based on the circuit we’ve already wired up. In the setup, the LCD is configured as having 16 columns and 2 rows, by calling lcd.begin(16,2). Because the first line never changes, it can be written in the setup. This is accomplished with a call to lcd.print(). Note that the cursor position does not need to be set first, because we want the text to be printed to position (0,0), which is already the default starting location. In the loop, the cursor is always set back to position (0,1) so that the number we print every second overwrites the previous number. The display updates once per second with the incremented timevalue.
What if we want to display information that cannot be expressed using normal text? Maybe we want to add a Greek letter, a degree sign, or some progress bars. Thankfully, the LiquidCrystal library supports the definition of custom characters that can be written to the display. In the next example, we use this capability to make an animated progress bar that scrolls across the display. After that, we take advantage of custom characters to add a degree sign when measuring and displaying temperature.
Creating a custom character is pretty straightforward. If we take a close look at the LCD, you’ll see that each character block is actually made up of a 5×8 grid of pixels. To create a custom character, we simply have to define the value of each of these pixels and send that information to the display. To try this out, we make a series of characters that will fill the second row of the display with an animated progress bar. Because each character space is 5 pixels wide, there will be a total of five custom characters: one with one column filled, one with two columns filled, and so on.
When we’re ready to write a custom character to the display, place the cursor in the right location and use the library’s write() function with the ID number:
In the preceding line, (byte) casts, or changes, the 0 to a byte value. This is necessary only when writing character ID 0 directly (without a variable that is defined to 0), to prevent the Arduino compiler from throwing an error caused by the variable type being ambiguous. Try removing the “byte cast” and observe the error that the Arduino IDE displays. We can write other character IDs without it, like this:
At the beginning of each pass through the loop, the 16-character-long string of spaces is written to the display, clearing the progress bar before it starts again. The outer for() loop iterates through all 16 positions. At each character position, the inner for() loop keeps the cursor there and writes an incrementing progress bar custom character to that location. The byte cast is not required here because the ID 0 is defined by the j variable in the for() loop.
You may have used an electronic device with a small Liquid Crystal Display (LCD) which has a textual hierarchical menu system for setting device configuration parameters. If you have tried writing menu code for your Arduino projects, you will recognise the challenge in developing a generic menu system for an open prototyping platform. This is because there are many input and display devices available, and a generic menu system must be independent of whichever input and display devices you wish to use. With our Arduino menu library, this independence is achieved by having the menu manager code use callback methods for handling user input and rendering the menu display.
To keep things simple, all coding examples have been targeted to work with an R3 Arduino Uno/Leonardo/Mega2560, and an LCD keypad shield similar to one illustrated above. There are numerous manufacturers of LCD keypad shields that have the same or similar pin connections, and you must ensure that the sample menu code uses the pin connections that are right for your shield. If the keypad buttons of your shield give different analog readings, you’ll need to make changes to file LcdKeypad.h. Bear in mind that the analog readings are not always consistent, which can lead to the occasional misreporting of a button press. Once you become familiar with the menu library, adapting it for use with other input and display devices should be straight-forward.
With numerous menu libraries readily available, why use this Arduino menu library? We think it is easier to use thanks to our online code generator, and has better memory efficiency with its use of PROGMEM. Watch the short video clip below and see for yourself.
Download the following Arduino sample project for testing out your menus. You’ll need to find and install the TimerOne library for the code to compile.
Our free online menu builder allows you to paste in a simple Xml representation of your menu, from which the Arduino menu source code is generated automatically. Use the sample Xml included in the project you just downloaded to get started.
After successfully uploading your Arduino project, test out your menu. Now that you have a menu in place, you can work on the main logic of your application. If you need to rework your menu in the future, the MenuData.h file has a copy of the xml that was used to generate it, which you can copy and paste in to the online menu builder.
You can use the downloaded sample Arduino project as a starting point for your own coding requirements. You will need to write your own code in the body of method processMenuCommand(byte cmdId) to determine what must be done when a menu item is selected. The cmdId parameter is the Id you associate with a menu item in your menu Xml file. Callback method getNavAction() handles user input, and callback method refreshMenuDisplay(byte refreshMode) renders the menu. To work with other input and display devices you’ll need to re-write the code in these methods. Some LCD keypad shields are not suited for hardware PWM backlight control, and as such the coding example uses a soft PWM alternative.
The Select button on the LCD shie