lcd touch screen code examples made in china

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.

As the code is a bit longer and for better understanding I will post the source code of the program in sections with description for each section. And at the end of this article I will post the complete source 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.

Now we need to make the buttons functional so that when we press them they would send us to the appropriate example. In the setup section we set the character ‘0’ to the currentPage variable, which will indicate that we are at the home screen. So if that’s true, and if we press on the screen this if statement would become true and using these lines here we will get the X and Y coordinates where the screen has been pressed. If that’s the area that covers the first button we will call the drawDistanceSensor() custom function which will activate the distance sensor example. Also we will set the character ‘1’ to the variable currentPage which will indicate that we are at the first example. The drawFrame() custom function is used for highlighting the button when it’s pressed. The same procedure goes for the two other buttons.

So the drawDistanceSensor() custom function needs to be called only once when the button is pressed in order to draw all the graphics of this example in similar way as we described for the home screen. However, the getDistance() custom function needs to be called repeatedly in order to print the latest results of the distance measured by the sensor.

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 recent time, China domestic companies like BOE have overtaken LCD manufacturers from Korea and Japan. For the first three quarters of 2020, China LCD companies shipped 97.01 million square meters TFT LCD. And China"s LCD display manufacturers expect to grab 70% global LCD panel shipments very soon.

BOE started LCD manufacturing in 1994, and has grown into the largest LCD manufacturers in the world. Who has the 1st generation 10.5 TFT LCD production line. BOE"s LCD products are widely used in areas like TV, monitor, mobile phone, laptop computer etc.

TianMa Microelectronics is a professional LCD and LCM manufacturer. The company owns generation 4.5 TFT LCD production lines, mainly focuses on making medium to small size LCD product. TianMa works on consult, design and manufacturing of LCD display. Its LCDs are used in medical, instrument, telecommunication and auto industries.

TCL CSOT (TCL China Star Optoelectronics Technology Co., Ltd), established in November, 2009. TCL has six LCD panel production lines commissioned, providing panels and modules for TV and mobile products. The products range from large, small & medium display panel and touch modules.

Established in 1996, Topway is a high-tech enterprise specializing in the design and manufacturing of industrial LCD module. Topway"s TFT LCD displays are known worldwide for their flexible use, reliable quality and reliable support. More than 20 years expertise coupled with longevity of LCD modules make Topway a trustworthy partner for decades. CMRC (market research institution belonged to Statistics China before) named Topway one of the top 10 LCD manufactures in China.

Founded in 2006, K&D Technology makes TFT-LCM, touch screen, finger print recognition and backlight. Its products are used in smart phone, tablet computer, laptop computer and so on.

The Company engages in the R&D, manufacturing, and sale of LCD panels. It offers LCD panels for notebook computers, desktop computer monitors, LCD TV sets, vehicle-mounted IPC, consumer electronics products, mobile devices, tablet PCs, desktop PCs, and industrial displays.

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 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 best way to calibrate is to use the calibration example program (comes with library) or use the serial monitor to detect your error.  However for this project since the size of buttons is large calibration should not be a big problem and I will also explain how you can calibrate your screen under the programming section below.

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, 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.

We need three libraries for this program to work; all these three libraries were given in the ZIP file you downloaded from the above provided link. I have simply included them in the code as shown below.

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.

Now, you can enter any number and perform your calculations. It is limited to only two operand and only operator for now. But, you can tweak the code to make it have lots of option.

You have to press the “C” to clear the value on screen each time after performing a calculation. Hope you understood the project and enjoyed building something similar. If you have any doubts feel free to post them on forums or on the comment section below. See you next time with another interesting project until then happy computing!!

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.

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.

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.

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 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 just used a string and 8 filled circles that change their colors in order. To draw circles around a static point ,You can use sin();  and cos(); functions. you should define the PI number . To change colors, you can use color565(); function and replace your RGB code.

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 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 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.

The speed of playing all the GIF files are edited and we made them faster or slower for better understanding. The speed of motions depends on the speed of your processor or type of code or size and thickness of elements in the code.

The LCD we use is a 2.8" TFT screen. It has a resolution of 320 × 240, as the following figure shows. There are 240 pixels each line and 320 pixels each column. We can use (x, y) coordinate to represent each pixel on screen.

Control signals for SSD1289 TFT Driver: lcd_reset, lcd_cs(chip select), lcd_rs(0 for register address, 1 for value), lcd_wr(0 for write, 1 for read), lcd_rd(set 0 all the time in this project).

We use 16-bit data for the TFT LCD touch screen. The SSD1289 TFT Driver has more than 40 registers. Data are wrote to these registers to initialize the TFT LCD touch screen. Related code is in the "LCD_Init()" function.

R44h specify the start/end positions of the window address in the horizontal direction by and address unit. High 8 bits are for the end position of the window, while low 8 bits are for the start position of the window. Then R45h/R46h are for the start/end positions of the window address in the vertical direction. R22h transforms all the GDDRAM data into 18-bit, and writes the data. Format for transforming data into 18-bit depends on the interface used. After writing to GDDRAM, address is automatically updated according to AM bit and ID bit. Access to GDDRAM during stand-by mode is not available. So from the registers above we can draw a pixel and draw a set of area. Write the addresses for start horizontal/vertical position to R4E/R4F, then write color to R22, and then by setting the CS to 0, the function of drawing a pixel is realized. Then by set the initial position to R4E and R4F, and then set the area to be drawn with R44h, R45h and R46h. After doing this, write the related color to R22h. For example, set the horizontal start position to 0, end position to 239; set the vertical start position to 0, end position to 319; set R4Eh and R4Fh to 0; then write a for loop to write the color to R22 for 240*320 times, then the whole screen will the paint the color you wrote. With the method above we construct some basic functions necessary for drawing chessboard and the menu.

The Touch Panel is of the same size as the LCD Screen and is transparent. We have to link the position of the place we touch with the display"s position for that place.

The ADS7843 is a resistive touch screen controller that incorporates a 12-bit 125 kHz sampling SAR typeA/D converter. It can detect the pressed screen location by performing two A/D conversions.

We first use writeSPI() to send command to the ADS7843, and read the X/Y position of the place you touch with the function readSPI(). This X/Y position is a 12bit value, and can be mapped exactly to the coordinate (0,239)/(0,319). For the reason that our screen is not big enough, we would have a lot of deviation if we map the coordinate to a smaller scale. So we still use the 12bit value for verifying the position.

The PENIRQ is connected to PIND2 of the microcontroller, which is the INT0 external interrupt. Usually the touch panel is not pressed, and the output of PENIRQ is always high. Whenever the touch panel is pressed, the PENIRQ would change to low. And this falling edge is caught by INT0, X/Y positions are read in INT0. And a problem came out, that is more than one falling edge will be generated when the touch panel is pressed. We solved this problem by using timer0.

Debounce strategy: Whenever the touchscreen is pressed, there will be a voltage drop, and causes an external interrupt. In the external interrupt ISR we record the coordinate of the point being touched. Based on observation of the number of coordinates being recorded for each touch on Putty, we made two integer buffer of size 40 to store the X-coordinate and Y-coordinate. Whenever a touch is made, it enters the timoer0 external interrupt. In this ISR, a XY coordinate is recorded, and we store the coordinates in the buffer. Before leaving this external interrupt ISR, we set the debounce timer to 500, the timer0 compare match interrupt ISR will be entered every 1ms, and in this ISR the debounce timer will be decreased by 1, when the debounce timer becomes 0, this means there is no touch for 0.5s, all the coordinates for the same touch should be all stored in the buffer. So we calculate the average value, and clear buffer for next touch.

In the function task(), identify a point on the chessboard according to the touched coordinates, if there is chessman on this point, and is of the same party as the before selected chessman, or there is no selected chessman, then set this chessman as the selected chessman, if there is a chessman, but it is of the other side, then call function eat_chessman, if the move is made successfully, then change the flag, means it is other ones turn to make a move, and clear the selected chessman. If there is no chessman on this point, and there is a selected chessman, then call function move_chessman(),if the move is made successfully, then change the flag, means it is other one‟s turn to make a move, and clear the selected chessman, means there is no selected chessman for now.

The mainpage of our program will draw the user interface. We start drawing the mainpage by drawing two rectangles with different colors. We also shows the string in the rectangles to tell the user how to start. One figure of what our mainpage looks like is shown below. When the user touch on either of the color bar, the LCD will jump to the corresponding page.

Guns (aka cannons) are labeled "G"for Black and "r" for Red. Each player has two cannons, which start on the row behind the soldiers, two points in front of the horses. Cannons move like chariots, any distance orthogonally without jumping, but can only capture by jumping a single piece, friend or foe, along the path of attack. The piece over which the cannon jumps is called the "cannon platform". Any number of unoccupied spaces, including none, may exist between the cannon, screen, and the piece to be captured.

The accuracy of the touch screen is good. The identification of coordinates (x,y) of the touched point is precise. Because of the limitation of touch screen size, the chessboard is “mini”, so we have to have a precise identification of the coordinates to distinguish different points on the chessboard, so that the game can be played smoothly. We spent a lot time on identify each point’s coordinate on the chessboard, and we got a good accuracy. So though the chessman and chessboard is mini, player can still select the chessman and move it to one legal point on the chessboard exactly.

The only disappointment with the hardware is its instability. Sometimes the touch screen will restart itself, and we have no idea how this happens. But this phenomenon is not frequent. We are still trying to figure this out.

The touch screen is designed to be easily usable by people. Because our project is implemented on the touch screen, and we have soldered the microcontroller and the touch screen together neatly, so it is convenient to carry.

During our one month"s project, we made some adjustments to our initial proposal. At first, we decided to display the "playpage" on the TV screen. The problem is that there is very limited time for us to implement related manipulation. So later we just fulfill all the functions just on a single touch screen. After this revision, we basically realize a Chinese chess game.

Because of the limitation of time, this app is not very mature, we just give indication for now it"s which player"s turn to make a movement using putty. And I think if sounds are added to this app, this would be much better. For example, it will produce different sounds if the player makes a wrong movement, or a chess is eaten. And "Undo" function should be added, this would not be difficult for us because we have a structure which includes the previous position of every chess. Another improvement should be speed up the execution time of our code it take a long time to program it into the chip. And we use 16 bits data for communication between the touch screen and Atmega1284P which means that we have not much pins left for other functions. So we can change this 16 bits communication to 8 bits. And this touch screen is a good platform for playing, so we can explore more games to be played on this platform.

For we use a different touch screen from the other people used before, first we meet a lot of difficulties. But after successfully make the touch screen work, I found that their rational are basically the same. With the right initialization and figuring out the registers useful for drawing, you can easily make any touch screen of this kind work.

Our decisions are consistent with the health, and welfare of the public, and to disclose promptly factors that might endanger the public or the environment. We never think of or do anything that will be harmful to the environment and people.( IEEE code of Ethics, Code 1)

We are honest with our reference and code. We cite and mark all the part from other"s help or online sources. We do most of the work ourselves in labs and we are sure these work are not the same to other sources( IEEE code of Ethics, code 3)

Our design aims at providing children the platform to have a understanding of electrical devices and the basic concepts of music. We also ( IEEE code of Ethics, code 5)

In doing this project, we treat fairly all persons regardless of such factors as race, religion, gender, disability, age, or national origin. ( IEEE code of Ethics, code 8)

Arduino development boards always help us to build a project easily and make it look more attractive. Programming an LCD with touch functionality may sound like a complicated task, but it can be made very easy by using Arduino libraries and extension modules. In this project, we will use a 3.5" Arduino TFT LCD to build an Arduino touchscreen calculator that can perform all basic calculations such as addition, subtraction, division, and multiplication.

Before we dive into the project, it is important to understand how this 3.5" TFT LCD module works and the model number used. Let"s take a look at the pinout of this 3.5" TFT LCD module.

As you can see, the module pins can be divided into four main categories, namely LCD command pins, LCD data pins, SD card pins and power pins, we don"t need to know the details of how these pins work because they will be implemented by the Arduino library.

You can also find an SD card slot on the bottom of the module shown above. This slot can be used to load an SD card with bmp image files, which can be displayed on our TFT LCD screen using the Arduino program.

Another important thing to keep in mind is your interface IC. there are many types of TFT modules on the market from Adafruit TFT LCD modules to cheap Chinese clones. A program that fits an Adafruit expansion board may not be the same for a Chinese expansion board. Therefore, it is very important to know which type of LCD LCD you are holding. This detail must be obtained from the supplier. If you have a cheap clone like mine, then it most likely uses driver IC ili9341. You can follow the official Arduino tutorial to try some basic example programs to get familiar with this LCD.

If you intend to use the touch screen function of a TFT LCD module, it must be calibrated to work properly. An LCD screen that is not calibrated is unlikely to work properly; for example, you may touch in one place and the TFT may think it is touching somewhere else. These calibration results are not the same for all boards, so you will have to do this work yourself.

The best way to calibrate is to use a calibration sample program (with a library) or use a serial monitor to detect your errors. But for this project, calibration should not be a big issue due to the large size of the buttons, and I will also explain how to calibrate your LCD in the programming section below.

The 3.5" TFT LCD is a great Arduino expansion board. You can push the LCD directly onto the top of the Arduino Uno and have it match the pins perfectly and slide them in. However, for safety reasons, the programming terminals of the Arduino UNO must use small insulating tape in case the terminals come into contact with your TFT LCD screen. the LCD assembled to the UNO development board looks like the following.

We use the SPFD5408 library to ensure that the arduino calculator code works properly. This is a modified Adafruit library that works seamlessly with our LCD TFT module. You can view the full program at the end of this article.

Now you can use the following code in the Arduino IDE and upload it to Arduino UNO to get the touchscreen calculator working. Further down the page, I"ll explain the code in small segments.

We need three libraries to make this program work properly. All three libraries are available for download in ZIP file format from the link provided above. I have simply included them in the code as shown below.

As mentioned before, we need to calibrate the LCD to make it work properly, but don"t worry the values given here are almost universal. The variables TS_MINX, TS_MINY, TS_MAXX and TS_MAXY determine the calibration of the screen. If you feel that the calibration is not ideal, you can make a slight change.

As we know, TFT LCD screens can display many colors, all of which must be entered as hexadecimal values. To make it more readable, we assign these values to a variable as shown below.

Okay, now we can move on to the programming part. This program involves three parts. One is to create a user interface for the calculator using buttons and displays. Then, detect the buttons based on user touch and finally calculate the results and display them. Let"s go through them one by one.

Another challenging task is to detect the user"s touch. Every time the user touches something, we are able to know the X and Y position of the pixel he touched. This value can be displayed on the serial monitor using println, as shown below.

Now, since we know the positions of all the boxes. When the user touches anywhere, we can predict the position he touches by comparing his (X, Y) value with the value of each box, as follows.

The final step is to calculate the results and display them on the TFT LCD screen. The arduino calculator can only perform two numeric operations. These two numbers are named as variables "Num1" and "Num2". The variable "Number" is given and taken from Num1 and Num2, and the result is obtained.

The process of working with this Arduino touch screen calculator is very simple. You need to upload the following code to the Arduino development board and then power it up. At this point, a calculator will be displayed on the LCD screen.

You can now enter any number and perform calculations. This is now limited to two operands and one operator. However, you can adjust the code so that there are more options.

After performing the calculation, you must press the "C" key to clear the value on the screen. I hope you understand this project and enjoy creating something similar. If you have any questions, please feel free to post them in the forum or below this post.

17.0 inch monitor lcd touch screen，air bonding and optical bonding optional, this monitor lcd touch screen mainly used in industrial, medical electronics, intelligent security, advertising terminals, financial terminals and other fields. support customization of various structures, surface treatment AG AR AF and other special effects, brightness etc. monitor lcd touch screen with Capacitive touch screeninterface iic/usb/rs232 interface optional, display can match the VGA/HDMI driver board according to customer demand;

Need to be reminded: Standard products haven"t special functions for the time being. If your product needs special features,such as: waterproof, explosion-proof, touch with gloves, etc,please feel free to contact me.Thanks!

As there are more and more touch panel application in all industries.Grahowlet has a good understanding of the difference between capacitive touch screen application and consumer electronics application. In order to ensure the smooth operation and market promotion of customers" end products,Graowlet would ensure following aspects

In most cases,customers in this industry might have debugging problems for both capacitance touch screen and the main-board.so Grahowlet strengthens technical guidance and povides software debugging assisance under the whole system for the customer.

End product application environment is various and complicated and in response to different environmental application requirements,Grahowlet specially improves the promotion of industrial touch programs such as Cypress and Elta MEL,Increasing the anti-interference and optimizing some special touch manners.

Waterproof, gloves touching, thick cover glass(maximum 15mm), sunlight readable, high brightness, backlight enchancing, AF,AF, AR, optical bonding .....