arduino tft lcd display tutorial supplier
In this Arduino touch screen tutorial we will learn how to use TFT LCD Touch Screen with Arduino. You can watch the following video or read the written tutorial below.
For this tutorial I composed three examples. The first example is distance measurement using ultrasonic sensor. The output from the sensor, or the distance is printed on the screen and using the touch screen we can select the units, either centimeters or inches.
As an example I am using a 3.2” TFT Touch Screen in a combination with a TFT LCD Arduino Mega Shield. We need a shield because the TFT Touch screen works at 3.3V and the Arduino Mega outputs are 5 V. For the first example I have the HC-SR04 ultrasonic sensor, then for the second example an RGB LED with three resistors and a push button for the game example. Also I had to make a custom made pin header like this, by soldering pin headers and bend on of them so I could insert them in between the Arduino Board and the TFT Shield.
Here’s the circuit schematic. We will use the GND pin, the digital pins from 8 to 13, as well as the pin number 14. As the 5V pins are already used by the TFT Screen I will use the pin number 13 as VCC, by setting it right away high in the setup section of code.
I will use the UTFT and URTouch libraries made by Henning Karlsen. Here I would like to say thanks to him for the incredible work he has done. The libraries enable really easy use of the TFT Screens, and they work with many different TFT screens sizes, shields and controllers. You can download these libraries from his website, RinkyDinkElectronics.com and also find a lot of demo examples and detailed documentation of how to use them.
After we include the libraries we need to create UTFT and URTouch objects. The parameters of these objects depends on the model of the TFT Screen and Shield and these details can be also found in the documentation of the libraries.
So now I will explain how we can make the home screen of the program. With the setBackColor() function we need to set the background color of the text, black one in our case. Then we need to set the color to white, set the big font and using the print() function, we will print the string “Arduino TFT Tutorial” at the center of the screen and 10 pixels down the Y – Axis of the screen. Next we will set the color to red and draw the red line below the text. After that we need to set the color back to white, and print the two other strings, “by HowToMechatronics.com” using the small font and “Select Example” using the big font.
Here’s that function which uses the ultrasonic sensor to calculate the distance and print the values with SevenSegNum font in green color, either in centimeters or inches. If you need more details how the ultrasonic sensor works you can check my particular tutorialfor that. Back in the loop section we can see what happens when we press the select unit buttons as well as the back button.
Ok next is the RGB LED Control example. If we press the second button, the drawLedControl() custom function will be called only once for drawing the graphic of that example and the setLedColor() custom function will be repeatedly called. In this function we use the touch screen to set the values of the 3 sliders from 0 to 255. With the if statements we confine the area of each slider and get the X value of the slider. So the values of the X coordinate of each slider are from 38 to 310 pixels and we need to map these values into values from 0 to 255 which will be used as a PWM signal for lighting up the LED. If you need more details how the RGB LED works you can check my particular tutorialfor that. The rest of the code in this custom function is for drawing the sliders. Back in the loop section we only have the back button which also turns off the LED when pressed.
In order the code to work and compile you will have to include an addition “.c” file in the same directory with the Arduino sketch. This file is for the third game example and it’s a bitmap of the bird. For more details how this part of the code work you can check my particular tutorial. Here you can download that file:
In this article, you will learn how to use TFT LCDs by Arduino boards. From basic commands to professional designs and technics are all explained here.
In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.
There are several components to achieve this. LEDs, 7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.
TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.
In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.
In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.
In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.
There are several components to achieve this. LEDs, 7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.
TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.
In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.
In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.
Size of displays affects your project parameters. Bigger Display is not always better. if you want to display high-resolution images and signs, you should choose a big size display with higher resolution. But it decreases the speed of your processing, needs more space and also needs more current to run.
After choosing the right display, It’s time to choose the right controller. If you want to display characters, tests, numbers and static images and the speed of display is not important, the Atmega328 Arduino boards (such as Arduino UNO) are a proper choice. If the size of your code is big, The UNO board may not be enough. You can use Arduino Mega2560 instead. And if you want to show high resolution images and motions with high speed, you should use the ARM core Arduino boards such as Arduino DUE.
In electronics/computer hardware a display driver is usually a semiconductor integrated circuit (but may alternatively comprise a state machine made of discrete logic and other components) which provides an interface function between a microprocessor, microcontroller, ASIC or general-purpose peripheral interface and a particular type of display device, e.g. LCD, LED, OLED, ePaper, CRT, Vacuum fluorescent or Nixie.
The display driver will typically accept commands and data using an industry-standard general-purpose serial or parallel interface, such as TTL, CMOS, RS232, SPI, I2C, etc. and generate signals with suitable voltage, current, timing and demultiplexing to make the display show the desired text or image.
The LCDs manufacturers use different drivers in their products. Some of them are more popular and some of them are very unknown. To run your display easily, you should use Arduino LCDs libraries and add them to your code. Otherwise running the display may be very difficult. There are many free libraries you can find on the internet but the important point about the libraries is their compatibility with the LCD’s driver. The driver of your LCD must be known by your library. In this article, we use the Adafruit GFX library and MCUFRIEND KBV library and example codes. You can download them from the following links.
You must add the library and then upload the code. If it is the first time you run an Arduino board, don’t worry. Just follow these steps:Go to www.arduino.cc/en/Main/Software and download the software of your OS. Install the IDE software as instructed.
By these two functions, You can find out the resolution of the display. Just add them to the code and put the outputs in a uint16_t variable. Then read it from the Serial port by Serial.println(); . First add Serial.begin(9600); in setup().
First you should convert your image to hex code. Download the software from the following link. if you don’t want to change the settings of the software, you must invert the color of the image and make the image horizontally mirrored and rotate it 90 degrees counterclockwise. Now add it to the software and convert it. Open the exported file and copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are sizes of image. you can change the color of the image in the last input.
Upload your image and download the converted file that the UTFT libraries can process. Now copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are size of the image.
In this template, We converted a .jpg image to .c file and added to the code, wrote a string and used the fade code to display. Then we used scroll code to move the screen left. Download the .h file and add it to the folder of the Arduino sketch.
In this template, We used sin(); and cos(); functions to draw Arcs with our desired thickness and displayed number by text printing function. Then we converted an image to hex code and added them to the code and displayed the image by bitmap function. Then we used draw lines function to change the style of the image. Download the .h file and add it to the folder of the Arduino sketch.
In this template, We created a function which accepts numbers as input and displays them as a pie chart. We just use draw arc and filled circle functions.
In this template, We added a converted image to code and then used two black and white arcs to create the pointer of volumes. Download the .h file and add it to the folder of the Arduino sketch.
In this template, We added a converted image and use the arc and print function to create this gauge. Download the .h file and add it to folder of the Arduino sketch.
while (a < b) { Serial.println(a); j = 80 * (sin(PI * a / 2000)); i = 80 * (cos(PI * a / 2000)); j2 = 50 * (sin(PI * a / 2000)); i2 = 50 * (cos(PI * a / 2000)); tft.drawLine(i2 + 235, j2 + 169, i + 235, j + 169, tft.color565(0, 255, 255)); tft.fillRect(200, 153, 75, 33, 0x0000); tft.setTextSize(3); tft.setTextColor(0xffff); if ((a/20)>99)
while (b < a) { j = 80 * (sin(PI * a / 2000)); i = 80 * (cos(PI * a / 2000)); j2 = 50 * (sin(PI * a / 2000)); i2 = 50 * (cos(PI * a / 2000)); tft.drawLine(i2 + 235, j2 + 169, i + 235, j + 169, tft.color565(0, 0, 0)); tft.fillRect(200, 153, 75, 33, 0x0000); tft.setTextSize(3); tft.setTextColor(0xffff); if ((a/20)>99)
In this template, We display simple images one after each other very fast by bitmap function. So you can make your animation by this trick. Download the .h file and add it to folder of the Arduino sketch.
In this template, We just display some images by RGBbitmap and bitmap functions. Just make a code for touchscreen and use this template. Download the .h file and add it to folder of the Arduino sketch.
No! For about the price of a familiar 2x16 LCD, you get a high resolution TFT display. For as low as $4 (shipping included!), it"s possible to buy a small, sharp TFT screen that can be interfaced with an Arduino. Moreover, it can display not just text, but elaborate graphics. These have been manufactured in the tens of millions for cell phones and other gadgets and devices, and that is the reason they are so cheap now. This makes it feasible to reuse them to give our electronic projects colorful graphic displays.
There are quite a number of small cheap TFT displays available on eBay and elsewhere. But, how is it possible to determine which ones will work with an Arduino? And what then? Here is the procedure:ID the display. With luck, it will have identifying information printed on it. Otherwise, it may involve matching its appearance with a picture on Google images. Determine the display"s resolution and the driver chip.
Find out whether there is an Arduino driver available. Google is your friend here. Henning Karlsen"s UTFT library works with many displays. (http://www.rinkydinkelectronics.com/library.php?i...)
Download and install the driver library. On a Linux machine, as root, copy the library archive file to the /usr/share/arduino/libraries directory and untar or unzip it.
Load an example sketch into the Arduino IDE, and then upload it to the attached Arduino board with wired-up TFT display. With luck, you will see text and/or graphics.
We"ll begin with a simple one. The ILI9163 display has a resolution of 128 x 128 pixels. With 8 pins in a single row, it works fine with a standard Arduino UNO or with a Mega. The hardware hookup is simple -- only 8 connections total! The library put together by a smart fella, by the name of sumotoy, makes it possible to display text in multiple colors and to draw lines.
Note that these come in two varieties, red and black. The red ones may need a bit of tweaking to format the display correctly -- see the comments in the README.md file. The TFT_ILI9163C.h file might need to be edited.
It is 5-volt friendly, since there is a 74HC450 IC on the circuit board that functions as a level shifter. These can be obtained for just a few bucks on eBay and elsewhere, for example -- $3.56 delivered from China. It uses Henning Karlsen"s UTFT library, and it does a fine job with text and graphics. Note that due to the memory requirement of UTFT, this display will work with a standard UNO only with extensive tweaking -- it would be necessary to delete pretty much all the graphics in the sketch, and just stay with text.
on the far side of the display. It has 220x176 resolution (hires!) and will accept either 3.3 or 5 volts. It will work hooked up to an Uno, and with a few pin changes, also with a Mega. The 11-pin row is for activating the display itself, and the 5-pin row for the SD socket on its back.
This one is a 2.2" (diagonal) display with 176x220 resolution and parallel interface. It has a standard ("Intel 8080") parallel interface, and works in both 8-bit and 16-bit modes. It uses the S6D0164 driver in Henning Karlsen"s UTFT library, and because of the memory requirements of same, works only with an Arduino Mega or Due. It has an SD card slot on its back
This one is a bit of an oddball. It"s a clone of the more common HY-TFT240, and it has two rows of pins, set at right angles to one another. To enable the display in 8-bit mode, only the row of pins along the narrow edge is used. The other row is for the SD card socket on the back, and for 16-bit mode. To interface with an Arduino ( Mega or Due), it uses Henning Karlsen"s UTFT library, and the driver is ILI9325C. Its resolution is 320x240 (hires!) and it incorporates both a touch screen and an SD card slot.
Having determined that a particular TFT display will work with the Arduino, it"s time to think about a more permanent solution -- constructing hard-wired and soldered plug-in boards. To make things easier, start with a blank protoshield as a base, and add sockets for the TFT displays to plug into. Each socket row will have a corresponding row next to it, with each individual hole "twinned" to the adjacent hole in the adjoining row by solder bridges, making them accessible to jumpers to connect to appropriate Arduino pins. An alternative is hard-wiring the socket pins to the Arduino pins, which is neater but limits the versatility of the board.
In step 5, you mention that the TFT01 display can"t be used with the UTFT library on an Arduino Uno because of its memory requirements. It can - all you have to do is edit memorysaver.h and disable any display models you"re not using.
I think you should add a disclaimer that the code might make the Arduino Uno unprogrammable afterward (due to use up the two 0 and 1 pin) and link to how to fix it: https://stackoverflow.com/questions/5290428/how-to-reset-an-arduino-board/8453576?sfb=2#84535760
Not at all - it was your Instructable that got me going with the display to begin with! We all build off each other"s work, to the benefit of everyone.0
Tho I realize this is quickly becoming legacy hardware, these 8,16 bit parallel spi with 4 wire controller 3.2in Taft touch display 240x380. It has become very inexpensive with ally of back stock world wide so incorporating them into any project is easier then ever. Sorry to my question. I’m having difficulty finding wiring solution for this lcd. It is a sd1289 3.3 and 5v ,40 pin parallel 8,16 bit. I do not want to use a extra shield,hat or cape or adapter. But there’s a lot of conflicting info about required lvl shifters for this model any help or links to info would be great .. thank you. I hope I gave enough information to understand what I’m adoing
#1 you need a data sheet for the display and pinout and the i/o board attached to the cable.Than before you buy check for a driver for this chip Raydium/RM69071.if no driver lib are you able to write one and do you have the necessary tools to work on this scale to wire it up ..if you answer no than search for an arduino ready product.WCH0
hooking up and adding a lib is no piece of cake insure the screen you buy is arduino ready and sold by a reputable shop with step by step directions...WCH0
I"m sorry that I can"t help you with this. You"ll have to do your own research. See if you can identify the chipset and find out if there"s an Arduino driver for it.0
Thanks for the wealth of knowledge! It is amazing at what is possible with items the average person can easily acquire. I hope to put some of your tips to use this winter as I would like to build sensors and other items for home automation and monitoring. Being able to have small displays around the house in addition to gathering and controlling things remotely will help the family see room conditions without going to the computer. The idea of a touchscreen control for cheap is mind blowing.
– 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.
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
Hi guys, welcome to today’s tutorial. Today, we will look on how to use the 1.8″ ST7735 colored TFT display with Arduino. The past few tutorials have been focused on how to use the Nokia 5110 LCD display extensively but there will be a time when we will need to use a colored display or something bigger with additional features, that’s where the 1.8″ ST7735 TFT display comes in.
The ST7735 TFT display is a 1.8″ display with a resolution of 128×160 pixels and can display a wide range of colors ( full 18-bit color, 262,144 shades!). The display uses the SPI protocol for communication and has its own pixel-addressable frame buffer which means it can be used with all kinds of microcontroller and you only need 4 i/o pins. To complement the display, it also comes with an SD card slot on which colored bitmaps can be loaded and easily displayed on the screen.
The schematics for this project is fairly easy as the only thing we will be connecting to the Arduino is the display. Connect the display to the Arduino as shown in the schematics below.
Due to variation in display pin out from different manufacturers and for clarity, the pin connection between the Arduino and the TFT display is mapped out below:
We will use two libraries from Adafruit to help us easily communicate with the LCD. The libraries include the Adafruit GFX library which can be downloaded here and the Adafruit ST7735 Library which can be downloaded here.
We will use two example sketches to demonstrate the use of the ST7735 TFT display. The first example is the lightweight TFT Display text example sketch from the Adafruit TFT examples. It can be accessed by going to examples -> TFT -> Arduino -> TFTDisplaytext. This example displays the analog value of pin A0 on the display. It is one of the easiest examples that can be used to demonstrate the ability of this display.
The second example is the graphics test example from the more capable and heavier Adafruit ST7735 Arduino library. I will explain this particular example as it features the use of the display for diverse purposes including the display of text and “animated” graphics. With the Adafruit ST7735 library installed, this example can be accessed by going to examples -> Adafruit ST7735 library -> graphics test.
The first thing, as usual, is to include the libraries to be used after which we declare the pins on the Arduino to which our LCD pins are connected to. We also make a slight change to the code setting reset pin as pin 8 and DC pin as pin 9 to match our schematics.
Next, we create an object of the library with the pins to which the LCD is connected on the Arduino as parameters. There are two options for this, feel free to choose the most preferred.
Next, we move to the void setup function where we initialize the screen and call different test functions to display certain texts or images. These functions can be edited to display what you want based on your project needs.
The complete code for this is available under the libraries example on the Arduino IDE. Don’t forget to change the DC and the RESET pin configuration in the code to match the schematics.
Uploading the code to the Arduino board brings a flash of different shapes and text with different colors on the display. I captured one and its shown in the image below.
That’s it for this tutorial guys, what interesting thing are you going to build with this display? Let’s get the conversation started. Feel free to reach me via the comment section if you have any questions as regards this project.
TFT LCDs are the most popular color displays – the displays in smartphones, tablets, and laptops are actually the TFT LCDs only. There are TFT LCD shields available for Arduino in a variety of sizes like 1.44″, 1.8″, 2.0″, 2.4″, and 2.8″. Arduino is quite a humble machine whenever it comes to process or control graphics. After all, it is a microcontroller platform, and graphical applications usually require much greater processing resources. Still, Arduino is capable enough to control small display units. TFT LCDs are colorful display screens that can host beautiful user interfaces.
Most of the smaller TFT LCD shields can be controlled using the Adafruit TFT LCD library. There is also a larger TFT LCD shield of 3.5 inches, with an ILI9486 8-bit driver.
The Adafruit library does not support the ILI9486 driver. Actually, the Adafruit library is written to control only TFT displays smaller than 3.5 inches. To control the 3.5 inch TFT LCD touch screen, we need another library. This is MCUFRIEND_kbv. The MCUFRIEND_kbv library is, in fact, even easier to use in comparison to the Adafruit TFT LCD library. This library only requires instantiating a TFT object and even does not require specifying pin connections.
TFT LCDs for ArduinoUser interfaces are an essential part of any embedded application. The user interface enables any interaction with the end-user and makes possible the ultimate use of the device. The user interfaces are hosted using a number of devices like seven-segments, character LCDs, graphical LCDs, and full-color TFT LCDs. Out of all these devices, only full-color TFT displays are capable of hosting sophisticated interfaces. A sophisticated user interface may have many data fields to display or may need to host menus and sub-menus or host interactive graphics. A TFT LCD is an active matrix LCD capable of hosting high-quality images.
Arduino operates at low frequency. That is why it is not possible to render high-definition images or videos with Arduino. However, Arduino can control a small TFT display screen rendering graphically enriched data and commands. By interfacing a TFT LCD touch screen with Arduino, it is possible to render interactive graphics, menus, charts, graphs, and user panels.
Some of the popular full-color TFT LCDs available for Arduino include 3.5″ 480×320 display, 2.8″ 400×200 display, 2.4″ 320×240 display and 1.8″ 220×176 display. A TFT screen of appropriate size and resolution can be selected as per a given application.
If the user interface has only graphical data and commands, Atmega328 Arduino boards can control the display. If the user interface is a large program hosting several menus and/or submenus, Arduino Mega2560 should be preferred to control the TFT display. If the user interface needs to host high-resolution images and motions, ARM core Arduino boards like the DUE should be used to control the TFT display.
MCUFRIEND_kbv libraryAdafruit TFT LCD library supports only small TFT displays. For large TFT display shields like 3.5-inch, 3.6-inch, 3.95-inch, including 2.4-inch and 2.8-inch TFT LCDs, MCUFRIEND_kbv library is useful. This library has been designed to control 28-pin TFT LCD shields for Arduino UNO. It also works with Arduino Mega2560. Apart from UNO and Mega2560, the library also supports LEONARDO, DUE, ZERO, and M0-PRO. It also runs on NUCLEO-F103 and TEENSY3.2 with Sparkfun Adapter. The Mcufriend-style shields tend to have a resistive TouchScreen on A1, 7, A2, 6 but are not always in the same direction rotation. The MCUFRIEND_kbv library can be included in an Arduino sketch from the library manager.
The 3.5-inch TFT LCD shield needs to be plugged atop the Arduino board. The Mcufriend-style shields are designed to fit into all the above-mentioned Arduino boards. The shields have a TFT touch screen that can display colorful images and interfaces and a micro SD card reader to save images and other data. A 3.5-inch TFT LCD touch screen has the following pin diagram.
How project worksThe code fills a rectangle, then draws a rectangle within which text “EEWORLDONLINE” is displayed. Then, lines, circles, rectangles, and squares are drawn on the screen. The project ends with a greeting and a message.
There is little information on the Internet with a combination of this 1.77 inch TFT LCD work on Arduino Mega board. Most of the information is covering the 1.8 inch TFT LCD, and it is a little bit tricky to make this works since the connections on the board, and the code/driver may be different from other LCDs. We use this opportunity to explain the technology behind it besides just showing the readers its schematics. Later, we"ll show how to display both the temperature and humidity on the LCD with the DHT-11 sensor.
In a simple analogy, a computer uses a computer program, device driver, to talk to hardware like a printer and in the Arduino board, there is a microcontroller also uses some drivers to communicate with the LCD device. The communication between the microcontroller and devices can be parallel and/or serial when we look at it from the data transmission level. When we wired two LED lights with two separate I/O PINs on the board, we let the microcontroller sending the data in a parallel fashion. In the serial transmission, the data transmit one bit of data at a time, sequentially, over a communication channel called the bus. In web programming, we have the luxury of sending more complex data on a broader bandwidth, like JSON, a key-value pair data, when comparing with the low-level programming in electronics. There is a pulsing technique controlled by a clock, transmitting one bit every clock pulse. In this way, it compensates for the narrow path for data to pass through while maintaining the understanding of who is talking to whom or how to interpret the pieces of bit information that a device receives. With the clock speed, we can distinguish the data chunk out from the signal stream. It acts like traffic lights in the busiest city where all devices in the SPI bus shared the same clock as it maintains the data flow synchronized and controlled. As a result, paired its data line with a clock signal, the data is transferred synchronously. Many protocols are using this type of methods to communicate, such as SPI, and I2C. In our case, the LCD uses the Serial Peripheral Interface (SPI) protocol to communicate with the microcontroller on the Arduino board. Just like on the Internet, HTTP is a protocol for data communication between a web server and a client computer.
The sequence of the events in serial data transmission is initialized when the SS pin set low as in active mode for the slave device. Otherwise, it simply ignores the data sent from the master or the microcontroller on the Arduino board in this scenario since all devices on the SPI bus share the MISO, MOSI, and SCLK lines and the message arrives at the slave devices at the same time. Only the devices that the master wants to communicate have its SS pin set low. During the data transmission, the master begins to toggle the clock line up and down at speed supported by the slave device. For each clock cycle, it sends one bit on the MOSI line, and receive one bit on the MISO line. Until stopping the toggling of the clock line, the transmission is complete, and now the SS pin is returned with a high state. A reset is triggered, and the next sequence of data transmission can be started again. It looks like a controlled escalator moving people up and down in light speed!
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);Two constructors in this class mean that there are two ways to create the tft object. For 1.8 inch LCD, you should use the first constructor shown above. In our case, the 1.77 inch LCD requires us to use the second constructor.
I hope this article helps you set up the 1.77 inch TFT LCD successfully. Sometimes it is difficult to know which library to use when your manufacturer does not provide you with anything else except this label on the package. Remember to make sure that the background and text colors must be different to display characters or else you cannot see anything.
The ST7789 TFT module contains a display controller with the same name: ST7789. It’s a color display that uses SPI interface protocol and requires 3, 4 or 5 control pins, it’s low cost and easy to use. This display is an IPS display, it comes in different sizes (1.3″, 1.54″ …) but all of them should have the same resolution of 240×240 pixel, this means it has 57600 pixels. This module works with 3.3V only and it doesn’t support 5V (not 5V tolerant).
The ST7789 display module shown in project circuit diagram has 7 pins: (from right to left): GND (ground), VCC, SCL (serial clock), SDA (serial data), RES (reset), DC (or D/C: data/command) and BLK (back light).
As mentioned above, the ST7789 TFT display controller works with 3.3V only (power supply and control lines). The display module is supplied with 3.3V (between VCC and GND) which comes from the Arduino board.
To connect the Arduino to the display module, I used voltage divider for each line which means there are 4 voltage dividers. Each voltage divider consists of 2.2k and 3.3k resistors, this drops the 5V into 3V which is sufficient.
The first library is a driver for the ST7789 TFT display which can be installed from Arduino IDE library manager (Sketch —> Include Library —> Manage Libraries …, in the search box write “st7789” and install the one from Adafruit).
Arduino has always helped to build projects easily and make them look more attractive. Programming an LCD screen with touch screen option might sound as a complicated task, but the Arduino libraries and shields had made it really easy. In this project we will use a 2.4” Arduino TFT LCD screen to build our own Arduino Touch Screen calculator that could perform all basic calculations like Addition, Subtraction, Division and Multiplication.
Before we actually dive into the project it is important to know, how this 2.4” TFT LCD Module works and what are the types present in it. Let us take a look at the pinouts of this 2.4” TFT LCD screen module.
As you can see there are 28 pins which will perfectly fit into any Arduino Uno / Arduino Mega Board. A small classification of these pins is given in the table below.
As you can see the pins can be classified in to four main classifications such as LCD Command Pins, LCD Data Pins, SD Card Pins and Power Pins, We need not know much about the detailed working of these pins since they will be take care by our Arduino Library.
You can also find an SD card slot at the bottom of the module shown above, which can be used to load an SD card with bmp image files, and these images can be displayed in our TFT LCD screen using the Arduino Program.
Another important thing to note is your Interface IC. There are many types of TFT modules available in the market starting from the original Adafruit TFT LCD module to cheap Chinese clones. A program which works perfectly for your Adafruit shield might not work the same for Chinese breakout boards. So, it is very important to know which types of LCD display your are holding in hand. This detail has to be obtained from the vendor. If you are having a cheap clone like mine then it is most probably using the ili9341 driver IC.You can follow this TFT LCD interfacing with Arduino tutorial to try out some basic example programs and get comfortable with the LCD screen. Also check out our other TFT LCD projects with Arduino here:
If you planning to use the touch screen function of your TFT LCD module, then you have to calibrate it to make it work properly. A LCD screen without calibration might work unlikely, for instance you might touch at one place and the TFT might respond for a touch at some other place. These calibrations results will not be similar for all boards and hence you are left on your own to do this.
The 2.4” TFT LCD screen is a perfect Arduino Shield. You can directly push the LCD screen on top of the Arduino Uno and it will perfectly match with the pins and slid in through. However, as matters of safety cover the Programming terminal of your Arduino UNO with a small insulation tape, just in case if the terminal comes in contact with your TFT LCD screen. The LCD assembled on UNO will look something like this below.
We are using the SPFD5408 Library to get this arduino calculator code working. This is a modified library of Adafruit and can work seamlessly with our LCD TFT Module. You can check the complete program at the end of this Article.
Now, open Arduino IDE and select Sketch -> Include Librarey -> Add .ZIP library. A browser window will open navigate to the ZIP file and click “OK”. You should notice “Library added to your Libraries” on the bottom-left corner of Arduino, if successful. A detailed guide to do the same is given in the Interfacing Tutorial.
Now, you can use the code below in your Arduino IDE and upload it to your Arduino UNO for the Touch Screen Calculator to work. Further down, I have explained the code into small segments.
As said earlier we need to calibrate the LCD screen to make it work as expected, but don’t worry the values given here are almost universal. The variables TS_MINX, TS_MINY, TS_MAXX, and TS_MAXY decide the calibration of the Screen. You can toy around them if you feel the calibration is not satisfactory.
As we know the TFT LCD screen can display a lot of colours, all these colours have to be entered in hex value. To make it more human readable we assign these values to a variable as shown below.
Okay now, we can get into the programming part. There are three sections involved in this program. One is creating a UI of a calculator with buttons and display. Then, detecting the buttons based on the users touch and finally calculating the results and display them. Let us get through them one by one.
This is where you can use a lot of your creativity to design the User Interface of calculator. I have simply made a basic layout of a calculator with 16 Buttons and one display unit. You have to construct the design just like you will draw something on MS paint. The libraries added will allow you to draw Lines, Rectangle, Circles, Chars, Strings and lot more of any preferred colour. You can understand the available functions from this article.
Another challenging task is detecting the user touch. Every time the user touches somewhere we will able to how where the X and Y position of the pixel he touched. This value can be displayed on the serial monitor using the println as shown below.
The final step is to calculate the result and display them on TFT LCD Screen. This arduino calculator can perform operation with 2 numbers only. These two numbers are named as variables “Num1” and “Num2”. The variable “Number” gives and takes value from Num1 and Num2 and also bears the result.
The working of this Arduino Touch Screen Calculator is simple. You have to upload the below given code on your Arduino and fire it up. You get the calculator displayed on your LCD screen.