arduino tft display and font library made in china

While I was looking for a TFT display for a project with Arduino, I found on several webstores some displays based on the ST7735 chip by Sitronix (datasheet).

Based on its datasheet, the ST7735 chip has a SPI (Serial Peripheral Interface) interface, but the pin names on the silk screen of my display “seem” to suggest an I2C interface (SDA, SCL…):

First identify – based on your Arduino board – which pins correspond to the different signals of the SPI bus. For the others, you can freely choose between the remaining pins.

(as you see, I connected the BLK pin directly to Vcc to have the backlight always on. You can also connect it to an Arduino digital pin to be able to control the backlight via software, for example if you need to save power).

Adafruit wrote a fantastic tutorial to explain how to use them, here I only want to show you how to setup the display for the connections I made earler:

If you’re using a board based on the esp32 chip and you need to display bitmap images, give a look to my library, SPIFFS_ImageReader, which perfectly integrates with the ones by Adafruit!

I am a Brit. So I seldom want to use accented characters. But you can mix and match printing with `u8g2_for_adafruit_gfx` object or regular `tft` object

Latin languages use the characters I need a lot. I am developing a teaching project for needy schools and all that was needed was to print these characters correctly on the screen.

The new library supports low cost ST7735 displays connected to an UNO,Leonardo or Mega via SPI, it is based on the Adafruit GFX library with encoded fonts to save space.

It supports the displays advertised on eBay typically shown with a "Minions" image shown and often quoted as being of OLED type (which they are not). This particular display has an unusual x and y offset, if you use the standard TFT library you get spurious pixels on two edges. This new library has a GREENTAB2 setting for these displays.

The 1K2 resistors are required to protect the display being damaged by the 5V logic levels from the UNO, these limit the current flow. Ideally we would use a level shifter but the resistors work fine.

This new library is a standalone library that contains the TFT driver as well as the graphics functions and fonts that were in the GFX library. This library has significant performance improvements when used with an UNO (or ATmega328 based Arduino) and MEGA.

Examples are included with the library, including graphics test programs. The example sketch TFT_Rainbow_one shows different ways of using the font support functions. This library now supports the "print" library so the formatting features of the "print" library can be used, for example to print to the TFT in Hexadecimal, for example:

The larger fonts are now Run Length Encoded (RLE) so that they occupy less FLASH space, this frees up space for the rest of the sketch. A byproduct of the RLE approach is that the font drawing is also speeded up so it is a win-win situation.

To use the F_AS_T performance option the ILI9341 based display must be connected to an MEGA as follows:MEGA +5V to display pin 1 (VCC) and pin 8 (LED) UNO 0V (GND) to display pin 2 (GND)

In the library Font 0 (GLCD font), 2, 4, 6 and 8 are enabled. Edit the Load_fonts.h file within the library folder to enable/disable fonts to save space.

TFT_ILI9341 library updated on 1st July 2015 to version 12, this latest version is attached here to step 8:Minor bug when rendering letter "T" in font 4 without background fixed

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).

This display shield has a controller built into it with RAM buffering, so that almost no work is done by the microcontroller. You can connect more sensors, buttons and LEDs.

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.

In this article, you will learn how to use TFT LCDs by Arduino boards. From basic commands to professional designs and technics are all explained here.

In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.

There are several components to achieve this. LEDs,  7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.

TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.

In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.

In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.

There are several components to achieve this. LEDs,  7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.

TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.

In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.

Size of displays affects your project parameters. Bigger Display is not always better. if you want to display high-resolution images and signs, you should choose a big size display with higher resolution. But it decreases the speed of your processing, needs more space and also needs more current to run.

After choosing the right display, It’s time to choose the right controller. If you want to display characters, tests, numbers and static images and the speed of display is not important, the Atmega328 Arduino boards (such as Arduino UNO) are a proper choice. If the size of your code is big, The UNO board may not be enough. You can use Arduino Mega2560 instead. And if you want to show high resolution images and motions with high speed, you should use the ARM core Arduino boards such as Arduino DUE.

In electronics/computer hardware a display driver is usually a semiconductor integrated circuit (but may alternatively comprise a state machine made of discrete logic and other components) which provides an interface function between a microprocessor, microcontroller, ASIC or general-purpose peripheral interface and a particular type of display device, e.g. LCD, LED, OLED, ePaper, CRT, Vacuum fluorescent or Nixie.

The display driver will typically accept commands and data using an industry-standard general-purpose serial or parallel interface, such as TTL, CMOS, RS232, SPI, I2C, etc. and generate signals with suitable voltage, current, timing and demultiplexing to make the display show the desired text or image.

The LCDs manufacturers use different drivers in their products. Some of them are more popular and some of them are very unknown. To run your display easily, you should use Arduino LCDs libraries and add them to your code. Otherwise running the display may be very difficult. There are many free libraries you can find on the internet but the important point about the libraries is their compatibility with the LCD’s driver. The driver of your LCD must be known by your library. In this article, we use the Adafruit GFX library and MCUFRIEND KBV library and example codes. You can download them from the following links.

You must add the library and then upload the code. If it is the first time you run an Arduino board, don’t worry. Just follow these steps:Go to www.arduino.cc/en/Main/Software and download the software of your OS. Install the IDE software as instructed.

By these two functions, You can find out the resolution of the display. Just add them to the code and put the outputs in a uint16_t variable. Then read it from the Serial port by Serial.println(); . First add Serial.begin(9600); in setup().

First you should convert your image to hex code. Download the software from the following link. if you don’t want to change the settings of the software, you must invert the color of the image and make the image horizontally mirrored and rotate it 90 degrees counterclockwise. Now add it to the software and convert it. Open the exported file and copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are sizes of image. you can change the color of the image in the last input.

Upload your image and download the converted file that the UTFT libraries can process. Now copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are size of the image.

In this template, We 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 created a function which accepts numbers as input and displays them as a pie chart. We just use draw arc and filled circle functions.

In this template, We added a converted image to code and then used two black and white arcs to create the pointer of volumes.  Download the .h file and add it to the folder of the Arduino sketch.

In this template, We added a converted image and use the arc and print function to create this gauge.  Download the .h file and add it to folder of the Arduino sketch.

while (a < b) { Serial.println(a); j = 80 * (sin(PI * a / 2000)); i = 80 * (cos(PI * a / 2000)); j2 = 50 * (sin(PI * a / 2000)); i2 = 50 * (cos(PI * a / 2000)); tft.drawLine(i2 + 235, j2 + 169, i + 235, j + 169, tft.color565(0, 255, 255)); tft.fillRect(200, 153, 75, 33, 0x0000); tft.setTextSize(3); tft.setTextColor(0xffff); if ((a/20)>99)

while (b < a) { j = 80 * (sin(PI * a / 2000)); i = 80 * (cos(PI * a / 2000)); j2 = 50 * (sin(PI * a / 2000)); i2 = 50 * (cos(PI * a / 2000)); tft.drawLine(i2 + 235, j2 + 169, i + 235, j + 169, tft.color565(0, 0, 0)); tft.fillRect(200, 153, 75, 33, 0x0000); tft.setTextSize(3); tft.setTextColor(0xffff); if ((a/20)>99)

In this template, We display simple images one after each other very fast by bitmap function. So you can make your animation by this trick.  Download the .h file and add it to folder of the Arduino sketch.

In this template, We just display some images by RGBbitmap and bitmap functions. Just make a code for touchscreen and use this template.  Download the .h file and add it to folder of the Arduino sketch.

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.

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 next example is controlling an RGB LED using these three RGB sliders. For example if we start to slide the blue slider, the LED will light up in blue and increase the light as we would go to the maximum value. So the sliders can move from 0 to 255 and with their combination we can set any color to the RGB LED,  but just keep in mind that the LED cannot represent the colors that much accurate.

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.

Next is the distance sensor button. First we need to set the color and then using the fillRoundRect() function we will draw the rounded rectangle. Then we will set the color back to white and using the drawRoundRect() function we will draw another rounded rectangle on top of the previous one, but this one will be without a fill so the overall appearance of the button looks like it has a frame. On top of the button we will print the text using the big font and the same background color as the fill of the button. The same procedure goes for the two other buttons.

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.

getDistance(); // Gets distance from the sensor and this function is repeatedly called while we are at the first example in order to print the lasest results from the distance sensor

Here’s that function which uses the ultrasonic sensor to calculate the distance and print the values with SevenSegNum font in green color, either in centimeters or inches. If you need more details how the ultrasonic sensor works you can check my particular tutorialfor that. Back in the loop section we can see what happens when we press the select unit buttons as well as the back button.

Ok next is the RGB LED Control example. If we press the second button, the drawLedControl() custom function will be called only once for drawing the graphic of that example and the setLedColor() custom function will be repeatedly called. In this function we use the touch screen to set the values of the 3 sliders from 0 to 255. With the if statements we confine the area of each slider and get the X value of the slider. So the values of the X coordinate of each slider are from 38 to 310 pixels and we need to map these values into values from 0 to 255 which will be used as a PWM signal for lighting up the LED. If you need more details how the RGB LED works you can check my particular tutorialfor that. The rest of the code in this custom function is for drawing the sliders. Back in the loop section we only have the back button which also turns off the LED when pressed.

In order the code to work and compile you will have to include an addition “.c” file in the same directory with the Arduino sketch. This file is for the third game example and it’s a bitmap of the bird. For more details how this part of the code work  you can check my particular tutorial. Here you can download that file:

getDistance(); // Gets distance from the sensor and this function is repeatedly called while we are at the first example in order to print the lasest results from the distance sensor

TFT_display_init() Perform display initialization sequence. Sets orientation to landscape; clears the screen. SPI interface must already be setup, tft_disp_type, _width, _height variables must be set.

compile_font_file Function which compiles font c source file to binary font file which can be used in TFT_setFont() function to select external font. Created file has the same name as source file and extension .fnt

The library contains proportional fonts, different sizes can be enabled/disabled at compile time to optimise the use of FLASH memory. The library has been tested with the UNO, Mega (ATmega328 or ATmega2560 processor) and the Leonardo compatible boards (ATmega32u4 processor).

The library is designed to be slim and fast. Typically a clear screen for a 160 x 128 TFT will complete in only 85ms. Images can be pulled from a SD Card and drawn in 200ms, not bad for a humble UNO!

The library is based on the Adafruit GFX library and the aim is to retain compatibility. Significant additions have been made to the library to boost the speed for AVR processors (it is typically 3 to 10 times faster) and to add new features. The new graphics functions include different size proportional fonts and formatting features. There are a significant number of example sketches to demonstrate the different features.

Configuration of the library font selections, pins used to interface with the TFT and other features is made by editting the User_Setup.h file in the library folder. Fonts and features can easily be disabled by commenting out lines.

A library for driving self-timed digital RGB/RGBW LEDs (WS2812, SK6812, NeoPixel, WS2813, etc.) using the Espressif ESP32 microcontroller"s RMT output peripheral.

LiquidCrystal fork for displays based on HD44780. Uses the IOAbstraction library to work with i2c, PCF8574, MCP23017, Shift registers, Arduino pins and ports interchangably.

The most powerful and popular available library for using 7/14/16 segment display, supporting daisy chaining so you can control mass amounts from your Arduino!

A simple library to display numbers, text and animation on 4 and 6 digit 7-segment TM1637 based display modules. Offers non-blocking animations and scrolling!

Monochrome LCD, OLED and eInk Library. Display controller: SSD1305, SSD1306, SSD1309, SSD1312, SSD1316, SSD1318, SSD1320, SSD1322, SSD1325, SSD1327, SSD1329, SSD1606, SSD1607, SH1106, SH1107, SH1108, SH1122, T6963, RA8835, LC7981, PCD8544, PCF8812, HX1230, UC1601, UC1604, UC1608, UC1610, UC1611, UC1617, UC1638, UC1701, ST7511, ST7528, ST7565, ST7567, ST7571, ST7586, ST7588, ST75160, ST75256, ST75320, NT7534, ST7920, IST3020, IST3088, IST7920, LD7032, KS0108, KS0713, HD44102, T7932, SED1520, SBN1661, IL3820, MAX7219, GP1287, GP1247, GU800. Interfaces: I2C, SPI, Parallel.

True color TFT and OLED library, Up to 18 Bit color depth. Supported display controller: ST7735, ILI9163, ILI9325, ILI9341, ILI9486,LD50T6160, PCF8833, SEPS225, SSD1331, SSD1351, HX8352C.

ILI9341 is a 262,144-color single-chip SOC driver for a-TFT liquid crystal display with resolution of 240RGBx320 dots, comprising a 720-channel source driver, a 320-channel gate driver, 172,800 bytes GRAM for graphic display data of 240RGBx320 dots, and power supply circuit. ILI9341 supports parallel 8-/9-/16-/18-bit data bus MCU interface, 6-/16-/18-bit data bus RGB interface and 3-/4-line serial peripheral interface (SPI). The moving picture area can be specified in internal GRAM by window address function. The specified window area can be updated selectively, so that moving picture can be displayed simultaneously independent of still picture area.

You can find ILI9341-based TFT displays in various sizes on eBay and Aliexpress. The one I chose for this tutorial is 2.2″ length along the diagonal, 240×320 pixels resolution, supports SPI interface, and can be purchased for less than $10.

Note that we will be using the hardware SPI module of the ESP8266 to drive the TFT LCD. The SPI communication pins are multiplexed with I/O pins D5 (SCK), D6 (MISO), and D7 (MOSI). The chip select (CS) and Data/Command (DC) signal lines are configurable through software.

For ILI9341-based TFT displays, there are some options for choosing the library for your application. The most common one is using Bodmer. We will use this library in this tutorial. So go ahead and download the

The library contains proportional fonts, different sizes can be enabled/disabled at compile time to optimise the use of FLASH memory. The library has been tested with the NodeMCU (ESP8266 based).

The library is based on the Adafruit GFX and Adafruit ILI9341 libraries and the aim is to retain compatibility. Significant additions have been made to the library to boost the speed for ESP8266 processors (it is typically 3 to 10 times faster) and to add new features. The new graphics functions include different size proportional fonts and formatting features. There are a significant number of example sketches to demonstrate the different features.

Configuration of the library font selections, pins used to interface with the TFT and other features is made by editting the User_Setup.h file in the library folder. Fonts and features can easily be disabled by commenting out lines.

As mentioned by the author, you need to open the User_Setup.h file inside the main library folder and modify the following two lines to match with our setup.

Now you are all set to try out tons of really cool built-in examples that come with the library. The following output corresponds to the TFT_Pie_Chart example.

My favorite example is TFT terminal, which implements a simple “Arduino IDE Serial Monitor” like serial receive terminal for monitoring debugging messages from another Arduino or ESP8266 board.

As a 2.4inch TFT display module with a resolution of 240 * 320, it uses the SPI interface for communication. LCD has an internal controller with basic functions, which can be used to draw points, lines, circles, and rectangles, and can display English, Chinese as well as pictures.

The 2.4inch LCD uses the PH2.0 8PIN interface, which can be connected to the Raspberry Pi according to the above table: (Please connect according to the pin definition table. The color of the wiring in the picture is for reference only, and the actual color shall prevail.)

The example we provide is based on STM32F103RBT6, and the connection method provided is also the corresponding pin of STM32F103RBT6. If you need to transplant the program, please connect according to the actual pin.

The LCD supports 12-bit, 16-bit, and 18-bit input color formats per pixel, namely RGB444, RGB565, and RGB666 three color formats, this demo uses RGB565 color format, which is also a commonly used RGB format.

For most LCD controllers, the communication mode of the controller can be configured, usually with an 8080 parallel interface, three-wire SPI, four-wire SPI, and other communication methods. This LCD uses a four-wire SPI communication interface, which can greatly save the GPIO port, and the communication speed will be faster.

Note: Different from the traditional SPI protocol, the data line from the slave to the master is hidden since the device only has a display requirement.

Framebuffer uses a video output device to drive a video display device from a memory buffer containing complete frame data. Simply put, a memory area is used to store the display content, and the display content can be changed by changing the data in the memory.

There is an open source project on github: fbcp-ili9341. Compared with other fbcp projects, this project uses partial refresh and DMA to achieve a speed of up to 60fps

Note: The script will replace the corresponding /boot/config.txt and /etc/rc.local and restart, if the user needs, please back up the relevant files in advance.

We have carried out the low-level encapsulation, if you need to know the internal implementation can go to the corresponding directory to check, for the reason that the hardware platform and the internal implementation are different

2.We use Dev libraries by default. If you need to change to BCM2835 or WiringPi libraries ,please open RaspberryPi\c\Makefile and modify lines 13-15 as follows:

If you need to draw pictures, or display Chinese and English characters, we provide some basic functions here about some graphics processing in the directory RaspberryPi\c\lib\GUI\GUI_Paint.c(.h).

Mirror: indicates the image mirroring mode. MIRROR_NONE, MIRROR_HORIZONTAL, MIRROR_VERTICAL, MIRROR_ORIGIN correspond to no mirror, horizontal mirror, vertical mirror, and image center mirror respectively.

Set points of the display position and color in the buffer: here is the core GUI function, processing points display position and color in the buffer.

The fill color of a certain window in the image buffer: the image buffer part of the window filled with a certain color, usually used to fresh the screen into blank, often used for time display, fresh the last second of the screen.

Draw circle: In the image buffer, draw a circle of Radius with (X_Center Y_Center) as the center. You can choose the color, the width of the line, and whether to fill the inside of the circle.

Write Ascii character: In the image buffer, use (Xstart Ystart) as the left vertex, write an Ascii character, you can select Ascii visual character library, font foreground color, font background color.

Write English string: In the image buffer, use (Xstart Ystart) as the left vertex, write a string of English characters, you can choose Ascii visual character library, font foreground color, font background color.

Write Chinese string: in the image buffer, use (Xstart Ystart) as the left vertex, write a string of Chinese characters, you can choose character font, font foreground color, font background color of the GB2312 encoding

Write numbers: In the image buffer,use (Xstart Ystart) as the left vertex, write a string of numbers, you can choose Ascii visual character library, font foreground color, font background color.

Display time: in the image buffer,use (Xstart Ystart) as the left vertex, display time,you can choose Ascii visual character font, font foreground color, font background color.;

Python has an image library PIL official library link, it do not need to write code from the logical layer like C, can directly call to the image library for image processing. The following will take 1.54inch LCD as an example, we provide a brief description for the demo.

The first parameter defines the color depth of the image, which is defined as "1" to indicate the bitmap of one-bit depth. The second parameter is a tuple that defines the width and height of the image. The third parameter defines the default color of the buffer, which is defined as "WHITE".

The first argument is a tuple of four elements. (20,10) is the coordinate value in the upper left corner of the rectangle, and (70,60) is the coordinate value in the lower right corner of the rectangle. Fill =" WHITE" means BLACK inside, and outline="BLACK" means the color of the outline is black.

Draw an inscribed circle in the square, the first parameter is a tuple of 4 elements, with (150, 15) as the upper left corner vertex of the square, (190, 55) as the lower right corner vertex of the square, specifying the level median line of the rectangular frame is the angle of 0 degrees, the second parameter indicates the starting angle, the third parameter indicates the ending angle, and fill = 0 indicates that the the color of the line is white.

The first parameter is the coordination of the enclosing rectangle. The second and third parameters are the beginning and end degrees of the circle. The fourth parameter is the fill color of the circle.

Note: Each character library contains different characters; If some characters cannot be displayed, it is recommended that you can refer to the encoding set ro used.

The first parameter is a tuple of 2 elements, with (40, 50) as the left vertex, the font is Font2, and the fill is the font color. You can directly make fill = "WHITE", because the regular color value is already defined Well, of course, you can also use fill = (128,255,128), the parentheses correspond to the values of the three RGB colors so that you can precisely control the color you want. The second sentence shows Micro Snow Electronics, using Font3, the font color is white.

The ST7789 TFT module contains a display controller with the same name: ST7789. It’s a color display that uses SPI interface protocol and requires 3, 4 or 5 control pins, it’s low cost and easy to use. This display is an IPS display, it comes in different sizes (1.3″, 1.54″ …) but all of them should have the same resolution of 240×240 pixel, this means it has 57600 pixels. This module works with 3.3V only and it doesn’t support 5V (not 5V tolerant).

The ST7789 display module shown in project circuit diagram has 7 pins: (from right to left): GND (ground), VCC, SCL (serial clock), SDA (serial data), RES (reset), DC (or D/C: data/command) and BLK (back light).

As mentioned above, the ST7789 TFT display controller works with 3.3V only (power supply and control lines). The display module is supplied with 3.3V (between VCC and GND) which comes from the Arduino board.

To connect the Arduino to the display module, I used voltage divider for each line which means there are 4 voltage dividers. Each voltage divider consists of 2.2k and 3.3k resistors, this drops the 5V into 3V which is sufficient.

The first library is a driver for the ST7789 TFT display which can be installed from Arduino IDE library manager (Sketch —> Include Library —> Manage Libraries …, in the search box write “st7789” and install the one from Adafruit).

Nextion is a Human Machine Interface （HMI） solution combining an onboard processor and memory touch display with Nextion Editor software for HMI GUI project development.

Using the Nextion Editor software, you can quickly develop the HMI GUI by drag-and-drop components (graphics, text, button, slider, etc.) and ASCII text-based instructions for coding how components interact on the display side.

Nextion HMI display connects to peripheral MCU via TTL Serial (5V, TX, RX, GND) to provide event notifications that peripheral MCU can act on, the peripheral MCU can easily update progress, and status back to Nextion display utilizing simple ASCII text-based instructions.

This post is an introduction to the Nextion display with the Arduino. We’re going to show you how to configure the display for the first time, download the needed resources, and how to integrate it with the Arduino UNO board. We’ll also make a simple graphical user interface to control the Arduino pins.

Nextion is a Human Machine Interface (HMI) solution. Nextion displays are resistive touchscreens that makes it easy to build a Graphical User Interface (GUI). It is a great solution to monitor and control processes, being mainly applied to IoT applications.

The Nextion has a built-in ARM microcontroller that controls the display, for example it takes care of generating the buttons, creating text, store images or change the background. The Nextion communicates with any microcontroller using serial communication at a 9600 baud rate.

To design the GUI, you use the Nextion Editor, in which you can add buttons, gauges, progress bars, text labels, and more to the user interface in an easy way. We have the 2.8” Nextion display basic model, that is shown in the following figure.

The best model for you, will depend on your needs. If you’re just getting started with Nextion, we recommend getting the 3.2” size which is the one used in the Nextion Editor examples (the examples also work with other sizes, but you need to make some changes). Additionally, this is the most used size, which means more open-source examples and resources for this size.

To get started with Nextion, first you need to install Nextion Editor. Go to https://nextion.itead.cc/, select the Resources tab, Download > Nextion Editor and install Nextion Editor. You can either download the .zip file or the .exe file.

Connecting the Nextion display to the Arduino is very straightforward. You just need to make four connections: GND, RX, TX, and +5V. These pins are labeled at the back of your display, as shown in the figure below.

You can power up the Nextion display directly from the Arduino 5V pin, but it is not recommended. Working with insufficient power supply may damage the display. So, you should use an external power source. You should use a 5V/1A power adaptor with a micro USB cable. Along with your Nextion display, you’ll also receive a USB to 2 pin connector, useful to connect the power adaptor to the display.

The best way to get familiar with a new software and a new device is to make a project example. Here we’re going to create a user interface in the Nextion display to control the Arduino pins, and display data.

The user interface has two pages: one controls two LEDs connected to the Arduino pins, and the other shows data gathered from the DHT11 temperature and humidity sensor;

We won’t cover step-by-step how to build the GUI in the Nextion display. But we’ll show you how to build the most important parts, so that you can learn how to actually build the user interface. After following the instructions, you should be able to complete the user interface yourself.

Additionally, we provide all the resources you need to complete this project. Here’s all the resources you need (be aware that you may need to change some settings on the user interface to match your display size):

Toolbox – this is where you have a wide variety of components you can add to the user interface, like pictures, progress bar, buttons, sliders, and much more.

Open Nextion Editor and go to File > New to create a new file. Give it a name and save it. Then, a window pops up to chose your Nextion model, as show in the figure below.

We’ll start by adding a background image. To use an image as a background, it should have the exact same dimensions as your Nextion display. We’re using the 2.8” display, so the background image needs to be 240×320 pixels. Check your display dimensions and edit your background image accordingly. As an example, we’re using the following image:

2. Click the (+) button and select your background image. The image will be added to the pictures list and it will be given an id. In this case it is 0.

Here you can select the font height, type, spacing and if you want it to be bold or not. Give it a name and click the Generate font button. After that, save the .zi file and add the generator font by clicking yes.

The font will be added to the Fonts library at the left bottom corner and it will be given an index. As this is your first font, it will have the index 0.

Note: At the time of writing this instructions there is an issue with font types. Whatever font type you chose, it will always look the same.Still, you can edit the font size and if it is bold or not.

At this moment, you can start adding components to the display area. For our project, drag three buttons, two labels and one slider, as shown in the figure below. Edit their looks as you like.

All components have an attribute called objname. This is the name of the component. Give good names to your components because you’ll need them later for the Arduino code. Also note that each component has one id number that is unique to that component in that page. The figure below shows the objname and id for the slider.

You should trigger an event for the touchable components (the buttons and the slider) so that the Arduino knows that a component was touched. You can trigger events when you press or when you release a component.

To do that, select one of the buttons, and in the event window, select the Touch Release Event tab, and put a tick on the Send Component ID option. Repeat this process for the other button, and the slider.

Our second page will display data from the DHT11 temperature and humidity sensor. We have several labels to hold the temperature in Celsius, the temperature in Fahrenheit, and the humidity. We also added a progress bar to display the humidity and an UPDATE button to refresh the readings. The bBack button redirects to page0.

Notice that we have labels to hold the units like “ºC”, “ºF” and “%”, and empty labels that will be filled with the readings when we have our Arduino code running.

In that window you can click on the buttons and see what happens. You should be able to swap between pages by clicking the corresponding buttons. You should also see the data returned when you click each button as highlighted in red in the figure above.

Once the GUI is ready, you need to write the Arduino code so that the Nextion can interact with the Arduino and vice-versa. Writing code to interact with the Nextion display is not straightforward for beginners, but it also isn’t as complicated as it may seem.

A good way to learn how to write code for the Arduino to interact with the Nextion display is to go to the examples folder in the Nextion library folder and explore. You should be able to copy and paste code to make the Arduino do what you want.

The first thing you should do is to take note of your components in the GUI that will interact with the Arduino and take note of their ID, names and page. Here’s a table of all the components the code will interact to (your components may have a different ID depending on the order you’ve added them to the GUI).

After that, you define led1 and led2. These variables refer to the digital pins 8 and 9 respectively. (led 1 will be controlled with the ON and OFF buttons of the user interface, and led2 brightness will be controlled using the slider).

Here you use the page ID, the component ID and their name – just check the table above with all the components. To define a text you use NexText, to define a button you use NexButton, for a slider you use NexSlider and for the progress bar you use NexProgressBar.

For the slider (h0), you have the following function that writes the current slider position on the tSlider label and sets led2 brightness accordingly:

Finally, you need a function for the bUpdate (the update button). When you click this button the DHT temperature and humidity sensor reads temperature and humidity and displays them on the corresponding labels, as well as the humidity on the progress bar. That is the bUpdatePopCallback() function.

In this post we’ve introduced you to the Nextion display. We’ve also created a simple application user interface in the Nextion display to control the Arduino pins. The application built is just an example for you to understand how to interface different components with the Arduino – we hope you’ve found the instructions as well as the example provided useful.

In our opinion, Nextion is a great display that makes the process of creating user interfaces simple and easy. Although the Nextion Editor has some issues and limitations it is a great choice for building interfaces for your electronics projects. We have a project on how to create a Node-RED physical interface with the Nextion display and an ESP8266 to control outputs. Feel free to take a look.