2.4 tft lcd touch shield arduino hello world in stock

// For better pressure precision, we need to know the resistance // between X+ and X- Use any multimeter to read it // For the one we"re using, its 300 ohms across the X plate TouchScreen ts = TouchScreen(XP, YP, XM, YM, 300);

tft.fillRect(0, 0, BOXSIZE, BOXSIZE, RED); tft.fillRect(BOXSIZE, 0, BOXSIZE, BOXSIZE, YELLOW); tft.fillRect(BOXSIZE*2, 0, BOXSIZE, BOXSIZE, GREEN); tft.fillRect(BOXSIZE*3, 0, BOXSIZE, BOXSIZE, CYAN); tft.fillRect(BOXSIZE*4, 0, BOXSIZE, BOXSIZE, BLUE); tft.fillRect(BOXSIZE*5, 0, BOXSIZE, BOXSIZE, MAGENTA); // tft.fillRect(BOXSIZE*6, 0, BOXSIZE, BOXSIZE, WHITE); tft.drawRect(0, 0, BOXSIZE, BOXSIZE, WHITE); currentcolor = RED; pinMode(13, OUTPUT); }

void loop() { digitalWrite(13, HIGH); // Recently Point was renamed TSPoint in the TouchScreen library // If you are using an older version of the library, use the // commented definition instead. Point p = ts.getPoint(); // TSPoint p = ts.getPoint(); digitalWrite(13, LOW);

// if sharing pins, you"ll need to fix the directions of the touchscreen pins //pinMode(XP, OUTPUT); pinMode(XM, OUTPUT); pinMode(YP, OUTPUT); //pinMode(YM, OUTPUT);

if (p.z > MINPRESSURE && p.z < MAXPRESSURE) { /* Serial.print("X = "); Serial.print(p.x); Serial.print("\tY = "); Serial.print(p.y); Serial.print("\tPressure = "); Serial.println(p.z); */ if (p.y < (TS_MINY-5)) { Serial.println("erase"); // press the bottom of the screen to erase tft.fillRect(0, BOXSIZE, tft.width(), tft.height()-BOXSIZE, BLACK); } // scale from 0->1023 to tft.width p.x = tft.width()-(map(p.x, TS_MINX, TS_MAXX, tft.width(), 0)); p.y = tft.height()-(map(p.y, TS_MINY, TS_MAXY, tft.height(), 0)); /* Serial.print("("); Serial.print(p.x); Serial.print(", "); Serial.print(p.y); Serial.println(")"); */ if (p.y < BOXSIZE) { oldcolor = currentcolor;

if (p.x < BOXSIZE) { currentcolor = RED; tft.drawRect(0, 0, BOXSIZE, BOXSIZE, WHITE); } else if (p.x < BOXSIZE*2) { currentcolor = YELLOW; tft.drawRect(BOXSIZE, 0, BOXSIZE, BOXSIZE, WHITE); } else if (p.x < BOXSIZE*3) { currentcolor = GREEN; tft.drawRect(BOXSIZE*2, 0, BOXSIZE, BOXSIZE, WHITE); } else if (p.x < BOXSIZE*4) { currentcolor = CYAN; tft.drawRect(BOXSIZE*3, 0, BOXSIZE, BOXSIZE, WHITE); } else if (p.x < BOXSIZE*5) { currentcolor = BLUE; tft.drawRect(BOXSIZE*4, 0, BOXSIZE, BOXSIZE, WHITE); } else if (p.x < BOXSIZE*6) { currentcolor = MAGENTA; tft.drawRect(BOXSIZE*5, 0, BOXSIZE, BOXSIZE, WHITE); }

if (oldcolor != currentcolor) { if (oldcolor == RED) tft.fillRect(0, 0, BOXSIZE, BOXSIZE, RED); if (oldcolor == YELLOW) tft.fillRect(BOXSIZE, 0, BOXSIZE, BOXSIZE, YELLOW); if (oldcolor == GREEN) tft.fillRect(BOXSIZE*2, 0, BOXSIZE, BOXSIZE, GREEN); if (oldcolor == CYAN) tft.fillRect(BOXSIZE*3, 0, BOXSIZE, BOXSIZE, CYAN); if (oldcolor == BLUE) tft.fillRect(BOXSIZE*4, 0, BOXSIZE, BOXSIZE, BLUE); if (oldcolor == MAGENTA) tft.fillRect(BOXSIZE*5, 0, BOXSIZE, BOXSIZE, MAGENTA); } } if (((p.y-PENRADIUS) > BOXSIZE) && ((p.y+PENRADIUS) < tft.height())) { tft.fillCircle(p.x, p.y, PENRADIUS, currentcolor); } } }

Hello, this a tutorial for beginners about the TFT LCD touch screen shield mounted on an Arduino UNO board, where we use some basic display functions and a little touch function, all this with simple and detailed functions.

Before proceeding, if you have the white screen problem or touch not detected or inverted you can check my previous tutorial it may help you with such issues ( Go to tutorial).

Here comes the “function of the show”, the code about the touch function creates two squares with different colors and then we associate every one with a simple function, you can check the paint example for more functions, this one shows the basic way of creating a button and it’s by associating the position where the square is drawn before, to a function like writing a text or clearing the screen then going to another page… it’s up to you now to create what you want.

Ever wanted to know how to make a simple drawing program on a LCD display, or are you curious about programming touch screens? Well, in this tutorial, we will be covering on how do you program a touchscreen display using the 2.4″ Touchscreen LCD sheild with Arduino Uno, which open up many possible applications which includes making a user friendly touch interface for making purchases, a simple touch-screen base remote control, and many more.

Hooking up the 2.4″ TFT LCD Touchscreen shield is realatively easy, since it is a Arduino shield. Just plug in the whole screen into the Arduino Uno, just note where the pins are located and connect the shield accordingly. There will be 2 parts in this tutoria, the first where you will test the functionality of the screen, and the next where you test the touch functionality of the screen.

For the graphics test of the 2.4″ screen, I used the sample sketch provided by the Adafruit TFTLCD library. The library can be downloaded here or here. (NOTE: You have to have the Adafruit GFX library installed before this library is installed, as the TFTLCD library uses the Adafruit GFX library for graphics. The library can be downloaded at https://github.com/adafruit/Adafruit-GFX-Library) A great thanks to Adafruit for their libraries.

Try uploading the example ‘graphictest’ sketch of the TFTLCD library. The screen should then be running the graphics test as shown above. If the screen displays nothing or displays only static, you may want to follow the steps taken below.

The modification I made in the example sketch is that I hard coded the LCD Driver, as for my case, the Arduino was unable to detect the LCD driver (and only produced noise on the screen).

Therefore, I set identifier variable as 0x9341 (located at line 60), which means that the shield is actually using a IL9341 LCD driver. Below are some useful links that may help if you encounter any difficulties:

This is the hardcoded sketch. Please upload the ‘graphictest’ example sketch of the TFTLCD library. If there is static or no display, you may need to modify the ‘identifier’ variable depending on which LCD driver you are using. Below is a sample code of the LCD Driver hard coded.// IMPORTANT: Adafruit_TFTLCD LIBRARY MUST BE SPECIFICALLY

Open & upload the ‘tftpaint’ example sketch from the TFTLCD library. (You may want to calibrate the screen first before using it. To do so, visit this post where I written a calibration code which can be used in this example. However, please note that certain parameters have to be changed for the calibration sketch to work with this 2.4″ screen.)

If the sketch does not run properly, you may want to do the following modifications. For my case, I need to modify a few parts, which includes:Hardcoding the LCD Driver

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.

The third example is a game. Actually it’s a replica of the popular Flappy Bird game for smartphones. We can play the game using the push button or even using the touch screen itself.

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.

Next we need to define the fonts that are coming with the libraries and also define some variables needed for the program. In the setup section we need to initiate the screen and the touch, define the pin modes for the connected sensor, the led and the button, and initially call the drawHomeSreen() custom function, which will draw the home screen of the program.

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.

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:

Note that the ILI9341 is actually the LCD driver (you can check the datasheet here) but, for simplicity, we will refer to the display using this name. In my case, I’m using a 2.4″ TFT display, with 240×320 pixels, bought at eBay.

There are a lot of Arduino libraries available that allow us to interact with these displays without having to worry about the lower level details. For this tutorial we are going to use the Arduino_GFX.

To finalize, the Data/Command (D/C) pin of the display will be connected to GPIO21 of the ESP32. When the D/C signal is low, data received by the display is interpreted as commands. When the D/C signal is high, the received data is interpreted as data (ex: arguments of commands or pixel data) [2]. Note however that we don’t need to worry about these details when using the Arduino_GFX library.

Then we will move on to the Arduino setup function. There, we will start by taking care of initializing a data bus accordingly to the device we are using. In our case, since we are using the ESP32, we need to create a bus of class Arduino_ESP32SPI.

Note that the concept of data bus is an abstraction that allows to use the library to control different devices with different SPI interface characteristics. The Arduino_ESP32SPI classe we have just created inherits from the Arduino_DataBus class. You can check the other implementations available here.

Next we are going to create an object of class Arduino_ILI9341. This class inherits from the Arduino_TFT class and allows us to interact with the display.

Finally we are going to write some text to our display by calling the print method, passing as input the message we want to print. For our test, we are going to pass a very simple “Hello world”.

Add evive library in your Arduino IDE; it has a lot of functions for TFT display. To initialise the TFT, you must add the function tft_init(INITR_BLACKTAB); in the beginning of the program. This function initialises the TFT screen with a black background.

To write on TFT, you must first set the cursor at the point where you want to write. For this, write the statement tft.setCursor (x,y);, where x and y are the coordinates on the screen. The top left corner on the TFT Screen is (1, 1). When you move to right on the screen, x increases, and when you move down, y value increases.

tft.print(): When this function is used to write text, the cursor remains in the same line. If you use this function the second time to write something new, it displays it immediately next to the previously written text. E,g, if you writetft.print(“Hi”); two times, the output on the screen will be HiHi.

tft.println(): This function adds a new line after the text is displayed on the screen. If you use this function to write something new, it will display the net in the new line. E.g. if you write tft.println(“Hi”); twice, the output on the screen will be

tft.setTextColor();this function sets color of text to color passed as argument in this function. For example tft.setTextColor(ST7735_WHITE) sets text color to white.

Arduino TFT LCD Touch Screen GSM Mobile Phone | Lightweight Arduino GSM Mobile Phone – Arduino Project Hub. 1. Nextion Display Based Mobile Phone using GSM & Arduino, 2. Overview | Arduin-o-Phone | Adafruit Learning System, 3. Turn your smartphone into a LCD shield for Arduino using TFT LCD, 4. LG KF700 cellphone TFT LCD on Arduino Mega, 5. How to fix white screen of tft touch screen with arduino | TFT, 6. 2.4” tft lcd shield mcufriend, 7. 2.4” tft lcd shield datasheet, 8. 2.4” tft lcd shield pinout, 9. 2.4” tft lcd shield interfacing with Arduino, 10. 2.4” tft lcd touch shield for arduino uno code, 11. arduino uno 2.4 tft lcd touch shield projects, 12. 2.4” tft lcd shield arduino mega 2560, 13. 2.4” tft lcd shield arduino mega example, 14. Arduino 2.4″ Touch Screen LCD Shield Tutorial – Arduino, 15. 2.4″ MCUFRIEND TFT Shield for Arduino UNO R3 , 16. TFT LCD 2.4″ Touch screen shield tutorial for beginners, 17. Interfacing and Fixing Touch Problem on TFT LCD 2.4″ Shield, 18. Arduino Calculator | 2.4″ TFT LCD Touch, 19. Arduino Touch Screen Calculator using TFT LCD – Circuit Digest, 20. How to Use 2.4″ TFT LCD Shield With Arduino Mega, 21. Arduino 2.4″ Touch Screen LCD Shield Tutorial, 22. Arduino TFT LCD Touch Screen Tutorial – HowToMechatronics, 23. 2.4” tft lcd shield mcufriend, 24. 2.4” tft lcd shield arduino mega 2560, 25. 2.4” tft lcd touch shield for arduino uno code, 26. arduino uno 2.4 tft lcd touch shield projects, 27. mcufriend 2.4 tft white screen, 28. arduino 2.4” tft lcd touch shield projects, 29. arduino tft shield, 30. 3.5” tft lcd shield arduino uno projects, 31. 2.4″ TFT LCD Shield touch screen module for Arduino Uno 32. Interfacing and fixing touch problem in Arduino TFT 2.4″ LCD, 33. 2.4″ TFT LCD Touch Shield Arduino Hello World, 34. Arduino Uno 2.4 TFT Display Shield MCU Friend Display, 35. Setting up 2.4 Inch TFT LCD Arduino Shield ILI9341 HX8347, 36. 2.4″ Arduino U TFT LCD Shield Display Module, 37. TFT LCD 2.4″ Touch screen shield tutorial – SURTR, 38. OPEN SMART 2.4 INCH TFT LCD Shield for Arduino, 39. 2.4″ TFT LCD Shield with Arduino Mega – Really Works, 40. 2.4″ TFT LCD Display Shield | ElectroPeak, 41. Arduino Tutorial: 2.4″ TFT Color Display ILI9341 240×320, 42. Arduino Touch Screen TFT LCD Tutorial, 43. Arduino Uno 2.4 TFT Display Shield MCU Friend Installing, 44. How to Display Images on 2.4inch TFT and Make It a Digital, 45. how to make a call using gsm module and Arduino, 46. Display Board – Arduino Project Hub – Arduino Create, 47. TFT Shield for Arduino Nano – Start – Arduino Project Hub,

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).

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).

In this guide we’re going to show you how you can use the 1.8 TFT display with the Arduino. You’ll learn how to wire the display, write text, draw shapes and display images on the screen.

The 1.8 TFT is a colorful display with 128 x 160 color pixels. The display can load images from an SD card – it has an SD card slot at the back. The following figure shows the screen front and back view.

This module uses SPI communication – see the wiring below . To control the display we’ll use the TFT library, which is already included with Arduino IDE 1.0.5 and later.

The TFT display communicates with the Arduino via SPI communication, so you need to include the SPI library on your code. We also use the TFT library to write and draw on the display.

In which “Hello, World!” is the text you want to display and the (x, y) coordinate is the location where you want to start display text on the screen.

The 1.8 TFT display can load images from the SD card. To read from the SD card you use the SD library, already included in the Arduino IDE software. Follow the next steps to display an image on the display:

In this guide we’ve shown you how to use the 1.8 TFT display with the Arduino: display text, draw shapes and display images. You can easily add a nice visual interface to your projects using this display.

The shield is fully assembled, tested, and ready to go. No wiring, no soldering! Simply plug it in and load up the library - you"ll have it running in under 10 minutes!

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.

The 2.4 ” tft lcd touch screen shield for Arduino can be used in a number of applications. However many of the shields available on the market are cloned versions which usually give many hobbyists hard time to use because they do not work properly with the common libraries for running TFT displays.

If you try uploading any of the examples in the Adafruit_GFX library for example the “graphicstest”, the lcd will just give a white screen. Nothing is displayed on the screen!

This problem is mainly due to using a newer version of the Adafruit GFX library. The 1.5.4 release of the Adafruit_GFX library broke compatibility with the Adafruit_TFTLCD library. So you have to roll back to Adafruit_GFX 1.5.3:

Another problem you may encounter with this tft lcd shield is the poor fuctioning of the touch screen. You may find the stylus pen is not well aligned with the content you are writing on the screen.

This is due to a bug in the TouchScreen library therefore you need to locate this library by following the path to where all the libraries for your Arduino IDE are stored.

First change it to return TSPoint(1023-x, 1023-y, z). Save the changes and then compile your code again and upload to check if the touch fuction is fine.

You can keep on adjusting the values of before x and y until you get an ideal point that works best for your tft lcd. Mine worked fine with return TSPoint(x, 1105-y, z)

Due to the limited processing power of the microprocessor in the Arduino, we need to store images in bmp format and they should be 320×240 pixels sizes.

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.

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.

Now, since we know the position of all the boxes. When a user touches anywhere we can predict where he has touched by comparing his (X,Y) values with the value for each box 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.