arduino lcd display serial monitor quotation
Plus, what you were doing was probably a kind of code bending/or else, using brute force and think that will work. You just opened the bracket of serialprintfloat and copy+paste everything from a sample code inside and re-closed it, without reading the code. Very not cool.
First of all for you, have respect for those that made suggestions. The original programmer that wrote the serialprintfloat told you it"s old code so you should toss it and just do Serial.println(a_floating_point_number).
In this article, we are going to link hardware and software of Arduino with the LCD. We are going to display typed Message on LCD 16/2 display using Serial Monitor, see where you can gather information on how to work with Serial Monitor, and how to work with 16/2 LCD display and also gain the pleasure of technical knowledge.
Open Arduino software. I have the latest version of the Arduino software. You can download Arduino software from www.Arduino.cc official website of Arduino.
Include the Header file for the liquid crystal. Overview on 16/2 LCD display is given in my article “Working with 16/2 LCD display.” Tools>> Include Library>> Liquid crystal.
The .hex file of Arduino will search for the Arduino board if Connected to the Laptop or system. If a device is found it will boot and command Arduino and Arduino will command LCD to display.
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 (°):
First you need to make sure the display initialisation is Ok. So, comment out the serial read block and try printing a hardcoded string on the display.
If you find out there is no initialisation problem you can continue with improving your serial read code. In the arduino forum there is a very good topic on serial communication basics by Robin2.
When you need to constantly update printed data on any display you need a string which is almost similar to the currently printed one or else it will flicker all the time and you won"t see anything.
This way only the time would change without the "clock" string. If you need to print strings that have nothing in common just add delay(ms) between the lcd.print() lines in order the change of the strings to be visible.
You will use the Serial Monitor to debug Arduino Software Sketches or to view data sent by a working Sketch. You must have an Arduino connected by USB to your computer to be able to activate the Serial Monitor.
To get familiar with using the Serial Monitor, Copy and Paste the following example Sketch into a blank Arduino IE window. Then Verify it and if it"s OK, Upload it. The next step will show you what to expect.
LCD Display Modules└ LEDs, LCDs & Display Modules└ Electronic Components & Semiconductors└ Electrical Equipment & Supplies└ Business & IndustrialAll CategoriesAntiquesArtBabyBooks & MagazinesBusiness & IndustrialCameras & PhotoCell Phones & AccessoriesClothing, Shoes & AccessoriesCoins & Paper MoneyCollectiblesComputers/Tablets & NetworkingConsumer ElectronicsCraftsDolls & BearsMovies & TVEntertainment MemorabiliaGift Cards & CouponsHealth & BeautyHome & GardenJewelry & WatchesMusicMusical Instruments & GearPet SuppliesPottery & GlassReal EstateSpecialty ServicesSporting GoodsSports Mem, Cards & Fan ShopStampsTickets & ExperiencesToys & HobbiesTravelVideo Games & ConsolesEverything Else
Clearing the LCD does not clear it but prints a character with 4 horizontal lines. Trying to move the cursor will print a different unrecognisable character. Sending things to the Arduino via the Serial port prints gibberish on the LCD.
Any idea why? Is there a way to work with the LCD and the serial port simultaneously? I require the serial port in order to control the Arduino from NodeJS.
This article includes everything you need to know about using acharacter I2C LCD with Arduino. I have included a wiring diagram and many example codes to help you get started.
In the second half, I will go into more detail on how to display custom characters and how you can use the other functions of the LiquidCrystal_I2C library.
Once you know how to display text and numbers on the LCD, I suggest you take a look at the articles below. In these tutorials, you will learn how to measure and display sensor data on the LCD.
Each rectangle is made up of a grid of 5×8 pixels. Later in this tutorial, I will show you how you can control the individual pixels to display custom characters on the LCD.
They all use the same HD44780 Hitachi LCD controller, so you can easily swap them. You will only need to change the size specifications in your Arduino code.
The 16×2 and 20×4 datasheets include the dimensions of the LCD and you can find more information about the Hitachi LCD driver in the HD44780 datasheet.
Note that an Arduino Uno with the R3 layout (1.0 pinout) also has the SDA (data line) and SCL (clock line) pin headers close to the AREF pin. Check the table below for more details.
After you have wired up the LCD, you will need to adjust the contrast of the display. On the I2C module, you will find a potentiometer that you can turn with a small screwdriver.
The LiquidCrystal_I2C library works in combination with the Wire.h library which allows you to communicate with I2C devices. This library comes pre-installed with the Arduino IDE.
To install this library, go to Tools > Manage Libraries (Ctrl + Shift + I on Windows) in the Arduino IDE. The Library Manager will open and update the list of installed libraries.
Note that counting starts at 0 and the first argument specifies the column. So lcd.setCursor(2,1) sets the cursor on the third column and the second row.
Next the string ‘Hello World!’ is printed with lcd.print("Hello World!"). Note that you need to place quotation marks (” “) around the text since we are printing a text string.
The example sketch above shows you the basics of displaying text on the LCD. Now we will take a look at the other functions of the LiquidCrystal_I2C library.
This function turns on automatic scrolling of the LCD. This causes each character output to the display to push previous characters over by one space.
If the current text direction is left-to-right (the default), the display scrolls to the left, if the current direction is right-to-left, the display scrolls to the right.
I would love to know what projects you plan on building (or have already built) with these LCDs. If you have any questions, suggestions or if you think that things are missing in this tutorial, please leave a comment down below.
This tutorial shows how to use the I2C LCD (Liquid Crystal Display) with the ESP32 using Arduino IDE. We’ll show you how to wire the display, install the library and try sample code to write text on the LCD: static text, and scroll long messages. You can also use this guide with the ESP8266.
Additionally, it comes with a built-in potentiometer you can use to adjust the contrast between the background and the characters on the LCD. On a “regular” LCD you need to add a potentiometer to the circuit to adjust the contrast.
Before displaying text on the LCD, you need to find the LCD I2C address. With the LCD properly wired to the ESP32, upload the following I2C Scanner sketch.
After uploading the code, open the Serial Monitor at a baud rate of 115200. Press the ESP32 EN button. The I2C address should be displayed in the Serial Monitor.
Displaying static text on the LCD is very simple. All you have to do is select where you want the characters to be displayed on the screen, and then send the message to the display.
The next two lines set the number of columns and rows of your LCD display. If you’re using a display with another size, you should modify those variables.
Then, you need to set the display address, the number of columns and number of rows. You should use the display address you’ve found in the previous step.
To display a message on the screen, first you need to set the cursor to where you want your message to be written. The following line sets the cursor to the first column, first row.
Scrolling text on the LCD is specially useful when you want to display messages longer than 16 characters. The library comes with built-in functions that allows you to scroll text. However, many people experience problems with those functions because:
The messageToScroll variable is displayed in the second row (1 corresponds to the second row), with a delay time of 250 ms (the GIF image is speed up 1.5x).
In a 16×2 LCD there are 32 blocks where you can display characters. Each block is made out of 5×8 tiny pixels. You can display custom characters by defining the state of each tiny pixel. For that, you can create a byte variable to hold the state of each pixel.
In summary, in this tutorial we’ve shown you how to use an I2C LCD display with the ESP32/ESP8266 with Arduino IDE: how to display static text, scrolling text and custom characters. This tutorial also works with the Arduino board, you just need to change the pin assignment to use the Arduino I2C pins.
We hope you’ve found this tutorial useful. If you like ESP32 and you want to learn more, we recommend enrolling in Learn ESP32 with Arduino IDE course.