arduino tft display libraries 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!

"C:\\Users\\David Prentice\\AppData\\Local\\Arduino15\\packages\\STM32\\tools\\arm-none-eabi-gcc\\6-2017-q2-update/bin/arm-none-eabi-size" -A "C:\\Users\\DAVIDP~1\\AppData\\Local\\Temp\\arduino_build_687817/graphicstest.ino.elf"

I found that the one I have uses ILI9335 and after some hacking I was able to make it work with UTFT (it uses a non standard pinout using PB[0:1] and PD[2:7] and needs LCD_RD at HIGH) but so far so good.

No, I do not understand why the module does not link all the SPI bus signals on the pcb. It would save 6 external pins. On the other hand, libraries like UTFT and URTouch have no concept of hardware SPI or bus.

I recently was in Shanghai SEG electronics market and bought in a hurry a 3.5" tft display for my project. Later I found out it"s an OCM-320240t350-a v1.5 resistive touchscreen display with UART communication.

I looked for libraries and docummentation on the internet, and only managed to find a datasheet written in Chinese. Since I don,t understand Chinese I was in a bit of a dead end. But with the help of google translate and some arduino library tutorials, I managed to make a library to control the tft.

I would like to share the list of tips from this forum for using these cheap touch screens from China with 40 pin connector. (I apologise to experienced users - this is for users without any experience with display troubleshooting, like me :D.)

a) First of all, I recommend you using the UTFT library with the URTouch add-on, because it supports a lot of display models, even that generic ones from China - Download here

b) Find your display"s controller model - it is on the manufacturer"s website or it is printed on your display. Be careful, if your display don"t work with this model selected, you have to use the trial and error method. I only have 16 bit displays - so far I know, there are two of these wrong labelled 16 bit displays:

You have to connect display"s VCC pin to 3.3 V - a lot of manufacturers says that their display have on board regulator and the display should be compatible with 5 V logic, but it fact it is not.

Don"t forget to set touch orientation according to URTouch_Supported_display_modules.pdf (this file is included with the library) with InitTouch(orientation);.

Calibrate display with URTouch_Calibration (URTouch/examples/Arduino/): Run sketch, calibrate it, copy values that you see on the screen to UTouchCD.h (URTouch/)

I presume that different display modules appear on the Chinese surplus market when phone models change production. They just get soldered to the universal pcb and the item sold on Ebay as Shields.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In this template, We converted a .jpg image to .c file and added to the code, wrote a string and used the fade code to display. Then we used scroll code to move the screen left. Download the .h file and add it to the folder of the Arduino sketch.

In this template, We used sin(); and cos(); functions to draw Arcs with our desired thickness and displayed number by text printing function. Then we converted an image to hex code and added them to the code and displayed the image by bitmap function. Then we used draw lines function to change the style of the image. Download the .h file and add it to the folder of the Arduino sketch.

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

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

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

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

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

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

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

This library enables you to use Hardware-based PWM channels on Arduino AVR ATtiny-based boards (ATtiny3217, etc.), using megaTinyCore, to create and output PWM to pins.

This library enables you to use ISR-based PWM channels on Arduino AVR ATtiny-based boards (ATtiny3217, etc.), using megaTinyCore, to create and output PWM any GPIO pin.

Small low-level classes and functions for Arduino: incrementMod(), decToBcd(). strcmp_PP(), PrintStr, PrintStrN, printPad{N}To(), printIntAsFloat(), TimingStats, formUrlEncode(), FCString, KString, hashDjb2(), binarySearch(), linearSearch(), isSorted(), reverse(), and so on.

Cyclic Redundancy Check (CRC) algorithms (crc8, crc16ccitt, crc32) programmatically converted from C99 code generated by pycrc (https://pycrc.org) to Arduino C++ using namespaces and PROGMEM flash memory.

Various sorting algorithms for Arduino, including Bubble Sort, Insertion Sort, Selection Sort, Shell Sort (3 versions), Comb Sort (4 versions), Quick Sort (3 versions).

Date, time, timezone classes for Arduino supporting the full IANA TZ Database to convert epoch seconds to date and time components in different time zones.

Clock classes for Arduino that provides an auto-incrementing count of seconds since a known epoch which can be synchronized from external sources such as an NTP server, a DS3231 RTC chip, or an STM32 RTC chip.

Useful Arduino utilities which are too small as separate libraries, but complex enough to be shared among multiple projects, and often have external dependencies to other libraries.

Fast and compact software I2C implementations (SimpleWireInterface, SimpleWireFastInterface) on Arduino platforms. Also provides adapter classes to allow the use of third party I2C libraries using the same API.

Enables Bluetooth® Low Energy connectivity on the Arduino MKR WiFi 1010, Arduino UNO WiFi Rev.2, Arduino Nano 33 IoT, Arduino Nano 33 BLE and Nicla Sense ME.

Simple Async HTTP Request library, supporting GET, POST, PUT, PATCH, DELETE and HEAD, on top of AsyncTCP libraries, such as AsyncTCP, ESPAsyncTCP, AsyncTCP_STM32, etc.. for ESP32 (including ESP32_S2, ESP32_S3 and ESP32_C3), WT32_ETH01 (ESP32 + LAN8720), ESP32 with LwIP ENC28J60, W5500 or W6100, ESP8266 (WiFi, W5x00 or ENC28J60) and currently STM32 with LAN8720 or built-in LAN8742A Ethernet.

Fully Asynchronous UDP Library for RASPBERRY_PI_PICO_W using CYW43439 WiFi with arduino-pico core. The library is easy to use and includes support for Unicast, Broadcast and Multicast environments.

The last hope for the desperate AVR programmer. A small (344 bytes) Arduino library to have real program traces and to find the place where your program hangs.

Enable inclusion of both ESP32 Blynk BT/BLE and WiFi libraries. Then select one at reboot or run both. Eliminate hardcoding your Wifi and Blynk credentials and configuration data saved in either LittleFS, SPIFFS or EEPROM.

Simple WiFiManager for Blynk and ESP32 with or without SSL, configuration data saved in either SPIFFS or EEPROM. Enable inclusion of both ESP32 Blynk BT/BLE and WiFi libraries. Then select one at reboot or run both. Eliminate hardcoding your Wifi and Blynk credentials and configuration data saved in either LittleFS, SPIFFS or EEPROM. Using AsyncWebServer instead of WebServer, with WiFi networks scanning for selection in Configuration Portal.

An Arduino library that takes input in degrees and output a string or integer for the 4, 8, 16, or 32 compass headings (like North, South, East, and West).

Directly interface Arduino, esp8266, and esp32 to DSC PowerSeries and Classic security systems for integration with home automation, remote control apps, notifications on alarm events, and emulating DSC panels to connect DSC keypads.

This library enables you to use Hardware-based PWM channels on Arduino AVRDx-based boards (AVR128Dx, AVR64Dx, AVR32Dx, etc.), using DxCore, to create and output PWM.

This library enables you to use ISR-based PWM channels on Arduino AVRDx-based boards (AVR128Dx, AVR64Dx, AVR32Dx, etc.), using DxCore, to create and output PWM any GPIO pin.

Small and easy to use Arduino library for using push buttons at INT0/pin2 and / or any PinChangeInterrupt pin.Functions for long and double press detection are included.Just connect buttons between ground and any pin of your Arduino - that"s itNo call of begin() or polling function like update() required. No blocking debouncing delay.

Arduino library for controlling standard LEDs in an easy way. EasyLed provides simple logical methods like led.on(), led.toggle(), led.flash(), led.isOff() and more.

OpenTherm Library to control Central Heating (CH), HVAC (Heating, Ventilation, Air Conditioning) or Solar systems by creating a thermostat using Arduino IDE and ESP32 / ESP8266 hardware.

Simple WebServer library for AVR, Teensy, SAM DUE, SAMD21, SAMD51, STM32F/L/H/G/WB/MP1, nRF52, SIPEED_MAIX_DUINO and RP2040-based (RASPBERRY_PI_PICO) boards using ESP8266/ESP32 AT-command shields with functions similar to those of ESP8266/ESP32 WebServer libraries

WizFi360/ESP8266/ESP32-AT library for Arduino providing an easy-to-use way to control WizFi360/ESP8266-AT/ESP32-AT WiFi shields using AT-commands. For AVR, Teensy, SAM DUE, SAMD21, SAMD51, STM32, nRF52, SIPEED_MAIX_DUINO and RP2040-based (Nano_RP2040_Connect, RASPBERRY_PI_PICO, etc.) boards using WizFi360/ESP8266/ESP32 AT-command shields.

ezTime - pronounced "Easy Time" - is a very easy to use Arduino time and date library that provides NTP network time lookups, extensive timezone support, formatted time and date strings, user events, millisecond precision and more.

A library for implementing fixed-point in-place Fast Fourier Transform on Arduino. It sacrifices precision and instead it is way faster than floating-point implementations.

The GCodeParser library is a lightweight G-Code parser for the Arduino using only a single character buffer to first collect a line of code (also called a "block") from a serial or file input and then parse that line into a code block and comments.

Arduino library for the Flysky/Turnigy RC iBUS protocol - servo (receive) and sensors/telemetry (send) using hardware UART (AVR, ESP32 and STM32 architectures)

An Arduino library to control the Iowa Scaled Engineering I2C-IRSENSE ( https://www.iascaled.com/store/I2C-IRSENSE ) reflective infrared proximity sensor.

Convinient way to map a push-button to a keyboard key. This library utilize the ability of 32u4-based Arduino-compatible boards to emulate USB-keyboard.

This library allows you to easily create light animations from an Arduino board or an ATtiny microcontroller (traffic lights, chaser, shopkeeper sign, etc.)

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

This library enables you to use ISR-based PWM channels on RP2040-based boards, such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, with Arduino-mbed (mbed_nano or mbed_rp2040) core to create and output PWM any GPIO pin.

Arduino library for MCP4728 quad channel, 12-bit voltage output Digital-to-Analog Convertor with non-volatile memory and I2C compatible Serial Interface

This library enables you to use ISR-based PWM channels on an Arduino megaAVR board, such as UNO WiFi Rev2, AVR_Nano_Every, etc., to create and output PWM any GPIO pin.

Replace Arduino methods with mocked versions and let you develop code without the hardware. Run parallel hardware and system development for greater efficiency.

A library package for ARDUINO acting as ModBus slave communicating through UART-to-RS485 converter. Originally written by Geabong github user. Improved by Łukasz Ślusarczyk.

This library enables you to use ISR-based PWM channels on an nRF52-based board using Arduino-mbed mbed_nano core such as Nano-33-BLE to create and output PWM any GPIO pin.

This library enables you to use ISR-based PWM channels on an nRF52-based board using Adafruit_nRF52_Arduino core such as Itsy-Bitsy nRF52840 to create and output PWM any GPIO pin.

An Arduino library for the Nano 33 BLE Sense that leverages Mbed OS to automatically place sensor measurements in a ring buffer that can be integrated into programs in a simple manner.

his library enables you to use Hardware-based PWM channels on RP2040-based boards, such as Nano_RP2040_Connect, RASPBERRY_PI_PICO, with either Arduino-mbed (mbed_nano or mbed_rp2040) or arduino-pico core to create and output PWM to any GPIO pin.

This library enables you to use SPI SD cards with RP2040-based boards such as Nano_RP2040_Connect, RASPBERRY_PI_PICO using either RP2040 Arduino-mbed or arduino-pico core.

This library enables you to use ISR-based PWM channels on RP2040-based boards, such as ADAFRUIT_FEATHER_RP2040, RASPBERRY_PI_PICO, etc., with arduino-pico core to create and output PWM any GPIO pin.

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!

Provides methods to retrieve instant and peak values from the ADC input. The Arduino library SensorWLED splits the input from a varying analog signal from the ADC into components, i.e., provides the capability of a sample-and-hold circuit.

Enables smooth servo movement. Linear as well as other (Cubic, Circular, Bounce, etc.) ease movements for servos are provided. The Arduino Servo library or PCA9685 servo expanders are supported.

Enables reading and writing on SD card using SD card slot connected to the SDIO/SDMMC-hardware of the STM32 MCU. For slots connected to SPI-hardware use the standard Arduino SD library.

Menu library for Arduino with IoT capabilities that supports many input and display devices with a designer UI, code generator, CLI, and strong remote control capability.

Adds tcUnicode UTF-8 support to Adafruit_GFX, U8G2, tcMenu, and TFT_eSPI graphics libraries with a graphical font creation utility available. Works with existing libraries

This library enables you to use Hardware-based PWM channels on Teensy boards, such as Teensy 2.x, Teensy LC, Teensy 3.x, Teensy 4.x, Teensy MicroMod, etc., to create and output PWM to pins. Using the same functions as other FastPWM libraries to enable you to port PWM code easily between platforms.

A library for creating Tickers which can call repeating functions. Replaces delay() with non-blocking functions. Recommanded for ESP and Arduino boards with mbed behind.

This library enables you to use Interrupt from Hardware Timers on an Arduino, Adafruit or Sparkfun AVR board, such as Nano, UNO, Mega, Leonardo, YUN, Teensy, Feather_32u4, Feather_328P, Pro Micro, etc.

This library enables you to use Interrupt from Hardware Timers on supported Arduino boards such as AVR, Mega-AVR, ESP8266, ESP32, SAMD, SAM DUE, nRF52, STM32F/L/H/G/WB/MP1, Teensy, Nano-33-BLE, RP2040-based boards, etc.

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!

Really tiny library to basic RTC functionality on Arduino. DS1307, DS3231 and DS3232 RTCs are supported. See https://github.com/Naguissa/uEEPROMLib for EEPROM support. Temperature, Alarms, SQWG, Power lost and RAM support.

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.

RFC6455-based WebSockets Server and Client for Arduino boards, such as nRF52, Portenta_H7, SAMD21, SAMD51, STM32F/L/H/G/WB/MP1, Teensy, SAM DUE, RP2040-based boards, besides ESP8266/ESP32 (ESP32, ESP32_S2, ESP32_S3 and ESP32_C3) and WT32_ETH01. Ethernet shields W5100, W5200, W5500, ENC28J60, Teensy 4.1 NativeEthernet/QNEthernet or Portenta_H7 WiFi/Ethernet. Supporting websocket only mode for Socket.IO. Ethernet_Generic library is used as default for W5x00. Now supporting RP2040W

Enables network connection (local and Internet) and WiFiStorage for SAM DUE, SAMD21, SAMD51, Teensy, AVR (328P, 32u4, 16u4, etc.), Mega, STM32F/L/H/G/WB/MP1, nRF52, NINA_B302_ublox, NINA_B112_ublox, RP2040-based boards, etc. in addition to Arduino MKR WiFi 1010, Arduino MKR VIDOR 4000, Arduino UNO WiFi Rev.2, Nano 33 IoT, Nano RP2040 Connect. Now with fix of severe limitation to permit sending much larger data than total 4K and using new WiFi101_Generic library

Simple WiFiWebServer, HTTP Client and WebSocket Client library for AVR Mega, megaAVR, Portenta_H7, Teensy, SAM DUE, SAMD21, SAMD51, STM32F/L/H/G/WB/MP1, nRF52, RP2040-based (Nano-RP2040-Connect, RASPBERRY_PI_PICO, RASPBERRY_PI_PICO_W, ESP32/ESP8266, etc.) boards using WiFi, such as WiFiNINA, WiFi101, CYW43439, U-Blox W101, W102, ESP8266/ESP32-AT modules/shields, with functions similar to those of ESP8266/ESP32 WebServer libraries.

Universal Timer with 1 millisecond resolution, based on system uptime (i.e. Arduino: millis() function or STM32: HAL_GetTick() function), supporting OOP principles.

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).

I changed the Adafruit libraries for TFT: GFX , TFTLCD and TouchScreen. I join all in this one library, the library SPFD5408, to avoid problems with duplicate libraries and enables also have the original library Adafruit ready for use in other projects with another TFT hardware.

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.

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.

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:

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.

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.

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).

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.

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.;

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.

Arduino has always helped to build projects easily and make them look more attractive.  Programming an LCD screen with touch screen option might sound as a complicated task, but the Arduino libraries and shields had made it really easy. In this project we will use a 2.4” Arduino TFT LCD screen to build our own Arduino Touch Screen calculator that could perform all basic calculations like Addition, Subtraction, Division and Multiplication.

Before we actually dive into the project it is important to know, how this 2.4” TFT LCD Module works and what are the types present in it. Let us take a look at the pinouts of this 2.4” TFT LCD screen module.

As you can see there are 28 pins which will perfectly fit into any Arduino Uno / Arduino Mega Board. A small classification of these pins is given in the table below.

As you can see the pins can be classified in to four main classifications such as LCD Command Pins, LCD Data Pins, SD Card Pins and Power Pins, We need not know much about the detailed working of these pins since they will be take care by our Arduino Library.

You can also find an SD card slot at the bottom of the module shown above, which can be used to load an SD card with bmp image files, and these images can be displayed in our TFT LCD screen using the Arduino Program.

Another important thing to note is your Interface IC. There are many types of TFT modules available in the market starting from the original Adafruit TFT LCD module to cheap Chinese clones. A program which works perfectly for your Adafruit shield might not work the same for Chinese breakout boards. So, it is very important to know which types of LCD display your are holding in hand. This detail has to be obtained from the vendor. If you are having a cheap clone like mine then it is most probably using the ili9341 driver IC.You can follow this TFT LCD interfacing with Arduino tutorial to try out some basic example programs and get comfortable with the LCD screen. Also check out our other TFT LCD projects with Arduino here:

If you planning to use the touch screen function of your TFT LCD module, then you have to calibrate it to make it work properly.  A LCD screen without calibration might work unlikely, for instance you might touch at one place and the TFT might respond for a touch at some other place. These calibrations results will not be similar for all boards and hence you are left on your own to do this.

The 2.4” TFT LCD screen is a perfect Arduino Shield. You can directly push the LCD screen on top of the Arduino Uno and it will perfectly match with the pins and slid in through. However, as matters of safety cover the Programming terminal of your Arduino UNO with a small insulation tape, just in case if the terminal comes in contact with your TFT LCD screen. The LCD assembled on UNO will look something like this below.

We are using the SPFD5408 Library to get this arduino calculator code working. This is a modified library of Adafruit and can work seamlessly with our LCD TFT Module. You can check the complete program at the end of this Article.

Now, open Arduino IDE and select Sketch -> Include Librarey -> Add .ZIP library. A browser window will open navigate to the ZIP file and click “OK”. You should notice “Library added to your Libraries” on the bottom-left corner of Arduino, if successful. A detailed guide to do the same is given in the Interfacing Tutorial.

Now, you can use the code below in your Arduino IDE and upload it to your Arduino UNO for the Touch Screen Calculator to work. Further down, I have explained the code into small segments.

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 we know the TFT LCD screen can display a lot of colours, all these colours have to be entered in hex value. To make it more human readable we assign these values to a variable as shown below.

Okay now, we can get into the programming part. There are three sections involved in this program. One is creating a UI of a calculator with buttons and display. Then, detecting the buttons based on the users touch and finally calculating the results and display them. Let us get through them one by one.

This is where you can use a lot of your creativity to design the User Interface of calculator. I have simply made a basic layout of a calculator with 16 Buttons and one display unit. You have to construct the design just like you will draw something on MS paint. The libraries added will allow you to draw Lines, Rectangle, Circles, Chars, Strings and lot more of any preferred colour. You can understand the available functions from this article.

Another challenging task is detecting the user touch. Every time the user touches somewhere we will able to how where the X and Y position of the pixel he touched. This value can be displayed on the serial monitor using the println as shown below.

The final step is to calculate the result and display them on TFT LCD Screen. This arduino calculator can perform operation with 2 numbers only. These two numbers are named as variables “Num1” and “Num2”. The variable “Number” gives and takes value from Num1 and Num2 and also bears the result.

The working of this Arduino Touch Screen Calculator is simple. You have to upload the below given code on your Arduino and fire it up. You get the calculator displayed on your LCD screen.