lcd touch screen tft 2.4 arduino free sample
In this tutorial, you will learn how to use and set up 2.4″ Touch LCD Shield for Arduino. First, you’ll see some general information about this shield. And after learning how to set the shield up, you’ll see 3 practical projects.
The role of screens in electronic projects is very important. Screens can be of very simple types such as 7 Segment or character LCDs or more advanced models like OLEDs and TFT LCDs.
One of the most important features of this LCD is including a touch panel. If you are about to use the LCD, you need to know the coordinates of the point you touch. To do so, you should upload the following code on your Arduino board and open the serial monitor. Then touch your desired location and write the coordinates displayed on the serial monitor. You can use this coordination in any other project.
To display pictures on this LCD you should save the picture in 24bit BMP colored format and size of 240*320. Then move them to SD card and put the SD card in the LCD shield. we use the following function to display pictures. This function has 3 arguments; the first one stands for the pictures name, and the second and third arguments are for length and width coordinates of the top left corner of the picture.
If you want to display pictures without using an SD card, you can convert it to code and then display it. You can display even several photos sequentially without delay to create an animation. (Check this) But be aware that in this case, Arduino UNO may not be suitable (because of low processor speed). We recommend using the Arduino Mega or Arduino DUE.
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.
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:
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 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, 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.
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!!
The AZ-Delivery 2.4” TFT LCD Touch Display boasts 320x 240 pixels with 16-bit color. It has Touch capabilities, a built-in SD card drive, and plugs straight onto the top of an Arduino UNO or Mega. Amazon charges less than £11 for this device. It offers a major step up from the tiny SSD1306 128×64 monochrome display.
The TFT screen is much larger than the SSD1306 128×64 and much more colourful. The package includes an SD card reader on the underside and a stylus for accurate touch-screen control.
The underside of the board has labels on the pins. As the board is an Arduino shield, it will only fit on a UNO in one position. The SD card reader sits between USB and the power socket. It will also plug into and Arduino MEGA 2560. J1 and J2 fit into the digital pins, covering D0 to D13, while J3 and J4 fit into the analog and power pins.
I searched the Web for drivers and examples and found a great deal of praise for the TFT graphics, reports of problems with the Touch control and nothing about the SD card reader on this board.
In the end I installed several libraries (with all dependencies): Adafruit GFX, Adafruit TFTLCD, Adafruit TouchScreen, Adafruit ILI9341, MCUFRIEND_kbv and SPFD5408-master. (The last 2 are not essential but include some interesting examples). The SD library is included in the basic Arduino set.
I’ve used GFX with mono displays such as SSD1306 and soon got the TFT display working. The following script gives some idea about what it can do. I’ve included pixels, text (of varying sizes), lines, rectangles, triangles, squares, graphs, screen rotation, and text on a path. I was very impressed with the clarity, speed, brightness, and colors produced.
Normally, when setting the colour of an RGB LED you have a range of 0-255 (0-FF hex) for each RGB component which gives white = FFFFFF, red = FF000, green FF00 and blue = FF. This is 24-bit colour and takes 3 bytes. 224 gives 16,777,216 different colours. The TFT screen is a 16-bit colour device which can display 65,536 different colours – more than enough. Here the range is limited to 5 bits each for red and blue and 6 bits for green. (Our eyes are more sensitive to green so It gets the extra bit of accuracy.)
The following sketch gives an indication of the colours available by converting an array of 24-bit colour values into their 16-bit equivalent and displaying them on the screen with the data. There are not enough pixels on the screen to display all the colours at once so the last part of the sketch takes out the least significant green bit and displays half the available colours six ways.
An obvious use for the SD reader is to log readings from sensors and display the results on the TFT display. Unfortunately, the shield covers and uses most of the pins. The solution is to connect just the SD reader and power pins with jump leads which leaves plenty of pins to collect data from sensors.
Most Arduino users seldom use string manipulation. The documentation and a few simple examples of how to use strings are well scattered over the Web and difficult to find. The first sketch demonstrates how to create a file of 5 records/lines, each made up from an integer, a string, and a floating-point variable. The file is called datalog6.txt.
This is the part that often causes the most trouble with many owners giving up at this point. It may be because there are several different configurations of the pins used to connect to the touch layers of the screen on the many varied breakout boards and shields using this display. In this case four of the pins are used, at different times, to control both the graphics or the touch elements of the screen.
This is a resistive touch screen, rather than a capacitive one. Above the graphics, layers are two transparent resistive layers held apart by tiny dimples. One is connected at the top and bottom and the other at the sides. A potential difference is applied across them and when the stylus or a finger presses on the screen an electrical connection is made between the resistive layers.
The Analog pins are used to measure the voltages at that point on the two resistive layers, one at a time, in the same manner as we read the voltage from the wiper of a potentiometer – a potential divider. Using these values, it is possible to calculate, quite accurately, the coordinates of the point on the screen where the pressure has been applied. Calibration is often needed to improve accuracy. Adafruit suggests reading the resistance across the X plate (XP = D8 and XM = A2). On my board, I got 341 Ohms. Use this value as SENSITIVITY.
Try running the sketch to draw on the screen. The BLACK palette ‘button’ clears the screen and the others change the ‘ink’ colour. If the dot drawn is not directly under the stylus you can adjust the ‘fudge factors’ in the scaling section.
As a final example here is a sketch which shows off the Touch screen with buttons, bar graphs and colours. The buttons allow the user to adjust the RGB mix to display all the possible colours available. If you find one you particularly like it displays the hex value of the 16-bit colour.
There is a small amount of jitter as the bar graph re-draws but overall, the shield works quickly and very well. After the screen has updated and waiting for a touch the image is steady, sharp, and bright. Once you have calibrated the touch device it is very accurate as demonstrated with the small (30×30 pixel buttons) and provides excellent, colorful graphics on a usefully large display.
I was very pleased with the quality of the display and the accuracy of the Touch device. It sits neatly and securely on a UNO or a MEGA 2560. With an SD card reader included it was excellent value and I will be making good use of it in the future.
Spice up your Arduino project with a beautiful large touchscreen display shield with built in microSD card connection. This TFT display is big 4"(3.97" diagonal) bright (6 white-LED backlight) and colorful (18-bit 262,000 different shades)! 480x800 pixels with individual pixel control. As a bonus, this display has a optional resistive touch panel with controller XPT2046 and capacitive touch panel with FT6336.
The shield is fully assembled, tested and ready to go. No wiring, no soldering! Simply plug it in and load up our library - you"ll have it running in under 10 minutes! Works best with any classic Arduino (Due/Mega 2560).
Of course, we wouldn"t just leave you with a datasheet and a "good luck!" - we"ve written a full open source graphics library at the bottom of this page that can draw pixels, lines, rectangles, circles and text. We also have a touch screen library that detects x,y and z (pressure) and example code to demonstrate all of it. The code is written for Arduino but can be easily ported to your favorite microcontroller!
If you"ve had a lot of Arduino DUEs go through your hands (or if you are just unlucky), chances are you’ve come across at least one that does not start-up properly.The symptom is simple: you power up the Arduino but it doesn’t appear to “boot”. Your code simply doesn"t start running.You might have noticed that resetting the board (by pressing the reset button) causes the board to start-up normally.The fix is simple,here is the solution.
Place the Adafruit_ILI9341 library folder your arduinosketchfolder/libraries/ folder. You may need to create the libraries subfolder if its your first library. Restart the IDE
Displaying a custom image or graphic on a LCD display is a very useful task as displays are now a premium way of providing feedback to users on any project. With this functionality, we can build projects that display our own logo, or display images that help users better understand a particular task the project is performing, providing an all-round improved User Experience (UX) for your Arduino or ESP8266 based project. Today’s tutorial will focus on how you can display graphics on most Arduino compatible displays.
The procedure described in this tutorial works with all color displays supported by Adafruit’s GFX library and also works for displays supported by the TFTLCD library from Adafruit with little modification. Some of the displays on which this procedure works include:
While these are the displays we have, and on which this tutorial was tested, we are confident it will work perfectly fine with most of the other Arduino compatible displays.
For each of the displays mentioned above, we have covered in past how to program and connect them to Arduino. You should check those tutorials, as they will give you the necessary background knowledge on how each of these displays works.
For this tutorial, we will use the 2.8″ ILI9325 TFT Display which offers a resolution of 320 x 340 pixels and we will display a bitmap image of a car.
To demonstrate how things work, we will use the 2.8″ TFT Display. The 2.8″ TFT display comes as a shield which plugs directly into the Arduino UNO as shown in the image below.
Not all Arduino displays are available as shields, so when working with any of them, connect the display as you would when displaying text (we recommend following the detailed tutorial for the display type you use of the above list). This means no special connection is required to display graphics.
Before an image is displayed on any of the Arduino screens, it needs to be converted to a C compatible hex file and that can only happen when the image is in bitmap form. Thus, our first task is to create a bitmap version of the graphics to be displayed or convert the existing image to a bitmap file. There are several tools that can be used for creation/conversion of bitmap images including, Corel Draw and Paint.net, but for this tutorial, we will use the Paint.net.
Your graphics could also include some text. Just ensure the background is black and the fill color is white if you plan to change the color within your Arduino code.
Image2Code is an easy-to-use, small Java utility to convert images into a byte array that can be used as a bitmap on displays that are compatible with the Adafruit-GFX or Adafruit TFTLCD (with little modification) library.
Paste the bit array in the graphics.c file and save. Since we have two graphics (the car and the text), You can paste their data array in the same file. check the graphics.c file attached to the zip file, under the download section to understand how to do this. Don’t forget to declare the data type as “const unsigned char“, add PROGEM in front of it and include the avr/pgmspace.h header file as shown in the image below. This instructs the code to store the graphics data in the program memory of the Arduino.
With this done, we are now ready to write the code. Do note that this procedure is the same for all kind of displays and all kind of graphics. Convert the graphics to a bitmap file and use the Img2code utility to convert it into a hex file which can then be used in your Arduino code.
To reduce the amount of code, and stress involved in displaying the graphics, we will use two wonderful libraries; The GFX library and the TFTLCD library from Adafruit.
The Adafruit libraries do not support all of the displays but there are several modifications of the libraries on the internet for more displays. If you are unable to find a modified version of the library suitable for your the display, all you need do is copy the code of the drawBitmap() function from the GFX library and paste it in the Arduino sketch for your project such that it becomes a user-defined function.
The first two are thex and y coordinates of a point on the screen where we want the image to be displayed. The next argument is the array in which the bitmap is loaded in our code, in this case, it will be the name of the car and the text array located in the graphics.c file. The next two arguments are the width and height of the bitmap in pixels, in other words, the resolution of the image. The last argument is the color of the bitmap, we can use any color we like. The bitmap data must be located in program memory since Arduino has a limited amount of RAM memory available.
As usual, we start writing the sketch by including the libraries required. For this procedure, we will use the TFTLCD library alone, since we are assuming you are using a display that is not supported by the GFX library.
Next, we specify the name of the graphics to be displayed; car and title. At this stage, you should have added the bit array for these two bitmaps in the graphics.c file and the file should be placed in the same folder as the Arduino sketch.
The last section of the code is the drawBitmap function itself, as earlier mentioned, to use the drawbitmap() function with the Adafruit TFTLCD library, we need to copy the function’s code and paste into the Arduino sketch.
Plug in your screen as shown above. If you are using any other display, connect it as shown in the corresponding linked tutorial. With the schematics in place, connect the Arduino board to your PC and upload the code. Don’t forget the graphics file needs to be in the same folder as the Arduino sketch.
That’s it for this tutorial guys. The procedure is the same for all kinds of Arduino compatible displays. If you get stuck while trying to replicate this using any other display, feel free to reach out to me via the comment sections below.