simple image display for 1.8 tft lcd free sample

2023-01-03 12:32:11

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

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

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

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

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

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

Note: some people find issues with this display when trying to read from the SD card. We don’t know why that happens. In fact, we tested a couple of times and it worked well, and then, when we were about to record to show you the final result, the display didn’t recognized the SD card anymore – we’re not sure if it’s a problem with the SD card holder that doesn’t establish a proper connection with the SD card. However, we are sure these instructions work, because we’ve tested them.

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

simple image display for 1.8 tft lcd free sample

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simple image display for 1.8 tft lcd free sample

Hi guys, welcome to today’s tutorial. Today, we will look on how to use the 1.8″ ST7735 colored TFT display with Arduino. The past few tutorials have been focused on how to use the Nokia 5110 LCD display extensively but there will be a time when we will need to use a colored display or something bigger with additional features, that’s where the 1.8″ ST7735 TFT display comes in.

The ST7735 TFT display is a 1.8″ display with a resolution of 128×160 pixels and can display a wide range of colors ( full 18-bit color, 262,144 shades!). The display uses the SPI protocol for communication and has its own pixel-addressable frame buffer which means it can be used with all kinds of microcontroller and you only need 4 i/o pins. To complement the display, it also comes with an SD card slot on which colored bitmaps can be loaded and easily displayed on the screen.

The schematics for this project is fairly easy as the only thing we will be connecting to the Arduino is the display. Connect the display to the Arduino as shown in the schematics below.

Due to variation in display pin out from different manufacturers and for clarity, the pin connection between the Arduino and the TFT display is mapped out below:

We will use two libraries from Adafruit to help us easily communicate with the LCD. The libraries include the Adafruit GFX library which can be downloaded here and the Adafruit ST7735 Library which can be downloaded here.

We will use two example sketches to demonstrate the use of the ST7735 TFT display. The first example is the lightweight TFT Display text example sketch from the Adafruit TFT examples. It can be accessed by going to examples -> TFT -> Arduino -> TFTDisplaytext. This example displays the analog value of pin A0 on the display. It is one of the easiest examples that can be used to demonstrate the ability of this display.

The second example is the graphics test example from the more capable and heavier Adafruit ST7735 Arduino library. I will explain this particular example as it features the use of the display for diverse purposes including the display of text and “animated” graphics. With the Adafruit ST7735 library installed, this example can be accessed by going to examples -> Adafruit ST7735 library -> graphics test.

The first thing, as usual, is to include the libraries to be used after which we declare the pins on the Arduino to which our LCD pins are connected to. We also make a slight change to the code setting reset pin as pin 8 and DC pin as pin 9 to match our schematics.

Next, we create an object of the library with the pins to which the LCD is connected on the Arduino as parameters. There are two options for this, feel free to choose the most preferred.

Next, we move to the void setup function where we initialize the screen and call different test functions to display certain texts or images. These functions can be edited to display what you want based on your project needs.

All the functions called under the void setup function, perform different functions, some draw lines, some, boxes and text with different font, color and size and they can all be edited to do what your project needs.

The complete code for this is available under the libraries example on the Arduino IDE. Don’t forget to change the DC and the RESET pin configuration in the code to match the schematics.

Uploading the code to the Arduino board brings a flash of different shapes and text with different colors on the display. I captured one and its shown in the image below.

That’s it for this tutorial guys, what interesting thing are you going to build with this display? Let’s get the conversation started. Feel free to reach me via the comment section if you have any questions as regards this project.

simple image display for 1.8 tft lcd free sample

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Many times to make any user interface or nicely display content, we use icons/images. In this Instructable, you will be displaying icons or logos or images on your TFT screen from Arduino with using ATmega (microcontroller used in Arduino) Flash memory. It does not require any SD Card to store bitmap images or USB connection to send image data. We will convert images from any image format like .bmp, .jpg, .jpeg, .png to its hexadecimal equivalent to be stored in flash memory of arduino mega (ATmega2560).

All microcontroller has Flash memory, where the codes are stored permanently. Arduino Mega has comparatively good amount of Flash memory, ie 256 KB of which 8 KB used by bootloader. We will be doing two things:Monochrome icons/images: The icons or images will be displayed with single color, but takes very less memory. Just 1bit for one pixel.

Colored icons/images: It depends on the TFT screen used, for eg. 1.8" SPI TFT with ST7735 driver has 16bit color. Images or icons will just look like your phone screen, but it takes lots of space. it takes 16bits (2bytes) for each pixel (16times more!!).

It requires a TFT screen compatible with arduino, few jumper cables (dupont wires), breadboard and is recommended to use 3.3V -5V level shifters (but it works without it also :P ). But we have used evive . It has all the things required to do this without any additional wiring!! Hence it helps in avoiding the repetitive task for bread-boarding. evive uses the most commonly used 1.8" SPI based TFT (ST7735R driver) having 160px by 128px along with Arduino Mega 2560 R3. Also has internal logic level shifters for ideal usage.

https://sourceforge.net/projects/lcd-image-convert...This tool has all the options for large varieties of screens available. You can even draw your own icon!!.

Also we may need to use some image resizing tool as most of the images available on internet are of very large size as compared to hoscreen. Option for Image Resizer:

If you are using the tool mentioned in last step, Please look at the images. It has lots of options to resize image for our usage. We can easily enter the value of "height" or "width" in pixels!.

Once you have the image ready, next step is to convert the image to some form of numbers as actually all images are represented by array/matrix of numbers. Since we are not going to use SD card to save images or logos or icons as its irritating everytime to have a micro SD card for this purpose, we will now convert images to hexadecimal. Then we will store it in Arduino Flash Memory.

Using the LCD_Image_Converter tool, we will get the image in hexadecimal form.Load the image usign File->Open->"SelectUrImage" If you want to edit image, use the editing tools.

Copy all the numbers!! (Here each pixel is stored in its binary form as image is monochrome. If the pixel is filled, then it will be 1 or else it will be 0)

Other option is to go for colored images (remember that it takes lot of Arduino Flash memory). Based on the TFT screen you will have to select some options like color format (1.8" SPI TFT SR7735R uses 16 bit colors: R5G6B5)Load the image usign File->Open->"SelectUrImage" If you want to edit image, use the editing tools.

Copy all the numbers!! (Here each pixel is stored in a 16bit hexadecimal number. From LSB (lowest significant bit), first 5 represent "blue", then 6 digits represent "green" and rest 5 are for red.)

Case 2: Since there is no direct function in Adafruit GFX library, we will have to write our own code for this. We will have to traverse pixel by pixel to draw image/icon.

This type of icons are very useful for making automation systems having a display bar. Such icons provide intuitiveness to users for your projects or machines.

simple image display for 1.8 tft lcd free sample

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().

simple image display for 1.8 tft lcd free sample

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.

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.

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.

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.

simple image display for 1.8 tft lcd free sample

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).

simple image display for 1.8 tft lcd free sample

This post shows how to draw bitmap images on the ST7735 TFT using Arduino UNO board where the Arduino loads the BMP images from SD card and print them on the display.

In the display module there is AMS1117-3V3 voltage regulator which supplies the display controller with 3.3V (because it works with 3.3V only). The regulator steps down the 5V that comes from the Arduino board into 3.3V.

All Arduino UNO output pins are 5V, connecting a 5V pin directly to the ST7735 display board may damage its controller circuit. To avoid that, I connected each control line of the display to the Arduino board through 1k ohm resistor.

The digital pins 10, 11, 12 and 13 are hardware SPI module pins of ATmega328P microcontroller (Arduino UNO microcontroller). The SD card and the ST7735 TFT share the same SPI bus.

The first library is a driver for the ST7735 TFT display which can be installed from Arduino IDE library manager (Sketch —> Include Library —> Manage Libraries …, in the search box write “st7735” and install the one from Adafruit).

simple image display for 1.8 tft lcd free sample

The display is driven by a ST7735R controller ( ST7735R-specifications.pdf (2.1 MB) ), can be used in a “slow” and a “fast” write mode, and is 3.3V/5V compatible.

Adafruit_ST7735 is the library we need to pair with the graphics library for hardware specific functions of the ST7735 TFT Display/SD-Card controller.

In the file dialog select the downloaded ZIP file and your library will be installed automatically. This will automatically install the library for you (requires Arduino 1.0.5 or newer). Restarting your Arduino software is recommended as it will make the examples visible in the examples menu.

The easiest way to remedy this is by extracting the GitHub ZIP file. Place the files in a directory with the proper library name (Adafruit_GFX, Adafruit_ST7735 or SD) and zip the folder (Adafruit_GFX, Adafruit_ST7735.zip, SD.zip). Now the Arduino software can read and install the library automatically for you.

Basically, besides the obvious backlight, we tell the controller first what we are talking to with the CS pins. CS(TFT) selects data to be for the Display, and CS(SD) to set data for the SD-Card. Data is written to the selected device through SDA (display) or MOSI (SD-Card). Data is read from the SD-Card through MISO.

So when using both display and SD-Card, and utilizing the Adafruit libraries with a SainSmart display, you will need to connect SDA to MOSI, and SCL to SCLK.

As mentioned before, the display has a SLOW and a FAST mode, each serving it’s own purpose. Do some experiments with both speeds to determine which one works for your application. Of course, the need of particular Arduino pins plays a role in this decision as well …

Note: Adafruit displays can have different colored tabs on the transparent label on your display. You might need to adapt your code if your display shows a little odd shift. I noticed that my SainSmart display (gree tab) behaves best with the code for the black tab – try them out to see which one works best for yours.

Low Speed display is about 1/5 of the speed of High Speed display, which makes it only suitable for particular purposes, but at least the SPI pins of the Arduino are available.

After connecting the display in Low Speed configuration, you can load the first example from the Arduino Software (“File” “Example” “Adafruit_ST7735” – recommend starting with the “graphictest“).

Below the code parts for a LOW SPEED display (pay attention to the highlighted lines) – keep in mind that the names of the pins in the code are based on the Adafruit display:

The SD-Card needs to be FAT-16 or FAT-32 formatted, single partition, and the BMP file needs to be placed in the root (ie. not in a directory or anything like that).

You can name your BMP file “parrot.bmp” or modify the Sketch to have the proper filename (in “spitftbitmap” line 70, and in “soft_spitftbitmap” line 74).

#define SD_CS 4 // Chip select line for SD card#define TFT_CS 10 // Chip select line for TFT display#define TFT_DC 9 // Data/command line for TFT#define TFT_RST 8 // Reset line for TFT (or connect to +5V)

As you have seen before the Adafruit_GFX library (supported by the Adafruit_ST7735 library) makes this easy for us – More information can be found at the GFX Reference page.

To use this in your Arduino Sketch: The first 2 characters represent RED, the second set of two characters is for GREEN and the last 2 characters represent BLUE. Add ‘0x’ in front of each of these hex values when using them (‘0x’ designates a hexadecimal value).

This function is used to indicate what corner of your display is considered (0,0), which in essence rotates the coordinate system 0, 90, 180 or 270 degrees.

However, if your application needs your screen sideways, then you’d want to rotate the screen 90 degrees, effectively changing the display from a 128×160 pixel (WxH) screen to a 160×128 pixel display. Valid values are: 0 (0 degrees), 1 (90 degrees), 2 (180 degrees) and 3 (270 degrees).

tft.print("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur adipiscing ante sed nibh tincidunt feugiat. Maecenas enim massa, fringilla sed malesuada et, malesuada sit amet turpis. Sed porttitor neque ut ante pretium vitae malesuada nunc bibendum. Nullam aliquet ultrices massa eu hendrerit. Ut sed nisi lorem. In vestibulum purus a tortor imperdiet posuere. ");

simple image display for 1.8 tft lcd free sample

Hello, this tutorial is a follow up of the 2 other ones about the 2.4″ TFT LCD Shield with Arduino UNO, so the first one was about Interfacing and fixing the touch function problem also inverted axis, then the second one was about using simple function to draw different shapes and how to create a touch button to activate some functions…

But today we’re about the reading of images from SD card and showing them on the screen, first don’t forget to plug your SD card with your computer and format it as FAT32 then transfert your images don’t forget that they should be “BMP” format, Bitmaps 24 !! To have a correct image the resolutions should be 240*320, little explanation:

So you can chose whatever suits you, either change the screen rotation or the image rotation on your PC… then remeber or copy the image name and that’s it, plug your SD card in the shield.

This is the library that worked for me:if you use this library but when trying with example codes it shows you a white screen, you should definitely look for the library that suits you.

Here are the codes I’ve used in the video in.ino format, don’t forget to change the name of the files you’re using. Don’t forget to check the tutorial in case you need some help.

simple image display for 1.8 tft lcd free sample

The TFT module is the heart of this product -- it contains all the subsystems that are required to make an image show up. Starting with one of the most obvious features; the LCD screen is a glass panel with small little cells of liquid crystal (LC) material that can be shifted from opaque to clear with an electronic signal (more on how LCDs work). For each of the 128x160 pixels in the screen there are three LC cells and each cell has either a red, green, or blue filter in it to color the light. A pixel gets colored when white light from the LED backlight passes through the filtered cells in varying amounts.

The amount of light passed through is controlled by the signal applied to the liquid crystal cells, but the sheer number of pins and complexity of those signals is totally impractical to control directly with a microcontroller. Fortunately some really smart cookies created a dedicated driver Integrated Circuit (IC) that stores pixel data and puts it on the screen for us. Connections to the driver, as well as the backlight, are broken out along a flexible flat printed circuit (FPC) cable - and that"s where we take over.

The FPC connector is convenient for two reasons. First, it"s extremely simple to (re)connect the display to the breakout board. Second, production of this product is made easier because all soldering can be done in our normal surface mount process.

To disconnect the TFT module just flip up the black locking bar with a finger or pair of tweezers and then gently pull the cable straight out from the connector. To put the cable back in, first make sure that the polarity indicators on the cable (1, 40) match up with those on the board and that the black locking bar is flipped up. Next push the cable in evenly for about 2mm.

The microSD card holder is there to relieve your microcontroller"s poor memory due to having to store hundreds of images of cats, or really whatever you want to keep there. The SD card is connected to the same SPI bus as the display, which in turn keeps the required pin count low.

Out of the box, the TFT will come with a large backing PCB that makes it easy to securely mount the display in a project. If you need a more flexible solution you can remove the display module, snap off half the backing board, and then re-insert the display module. When this is done you"ll be left with the bare minimum frame around the display to more seamlessly integrate with your project.

The pinout of this breakout includes the standard SPI interfaces for both the TFT and the microSD card as well as a few specialty pins. You can power the breakout with either 5V or 3.3V thanks to the onboard voltage regulator and level shifter.

D/C : This is a special signal found in many display controllers. When it is high the incoming data is interpreted as data as opposed to commands when it is low.

TE : Tearing Effect is an optional output from the display to synchronize data writes - to avoid the "Tearing Effect" that is seen when data is changed halfway through a screen refresh

simple image display for 1.8 tft lcd free sample

Recently, I had the idea to make a digital picture frame—one of these kinds which load images from SD cards and show each image for some time. I was remembering myself that I already own a small TFT display, the KMR-1.8 SPI, that works out of the box with an Arduino Uno. When I digged up my KMR-1.8 SPI, I realized that it has also an in-built SD card reader. Moreover, I looked up the Internet and found ready-to-use libraries for the in-built SD card reader as well as showing images on the TFT display. For these reasons, I thought making such an digital picture frame will turn out very easy.

When I started to implement my first lines of codes and started to connect my Arduino Uno to the KMR-1.8 SPI, I ran into two major problems. First, the colors of my image file did not match to the colors displayed by the KMR-1.8 (red and blue were interchanged). Second, my first prototypes stopped to work after about 5 minutes. The application started to freeze and showed the same image forever instead of displaying the next image after a chosen time.

I did some research on the Internet and I found out that many people ran into similar problems. The second problem seemed to be caused by some memory leaks in the code. Nevertheless, I did not came across any example code that worked out of the box for my setup. Therefore, I want to share how I made it work.

There exists various versions of so-called “1.8 TFT displays” from different manufacturers. Not all of them are 100% compatible to each other. Therefore, if you own a TFT display and want to use my tutorial to make it work, please check if your TFT display really matches the version I used in this tutorial:

The source code relies on three header files (and libraries): SPI.h (Link), SD.h (Link) and TFT.h (Link). Please make sure that all of them are correctly installed before trying out my source code (In Arduino IDE: Tools -> Manage Libraries…).

I overcame the first problem by not using the default initialization method (“TFTscreen.begin();”) of the TFT library. Instead, I looked up whats inside the “begin”-method. I found a method called “initR” which has a parameter that allows to perform the initialization for a specific chip. Here, the parameter value “INITR_BLACKTAB” worked for me as the colors were then shown correctly. In addition, I call the method “setRotation” with parameter value “1” in order to be conform to the default initialization method. In the end, the code for the setting up the TFT library object looks like this:// ...

I solved the second problem (application freezes after some time) by avoiding any possible memory leak, i.e. to “free” every bit of memory that was reserved before as soon as it is not needed anymore. Therefore, you will find a lot of “close”-method calls as well as some weird string handling. When I wrote the code, I thought I could simplify a few things. However, the memory leak problems came back. So, the code might look weird but it works :)

if ((filename_len >= 4 && strcmp(name + filename_len - 4, ".BMP") == 0)) { // check if the current filename ends with ".BMP". If so, we might have an image.

The code looks for image files (*.BMP) on the SD card and shows each image for 60 seconds. You can change the display time by setting “DELAY_IMAGE_SWAP” to a new value.

Important Note: The image files on the SD card must be stored as BMP with a resolution of 160x128 pixels (width x height). Moreover, long file names and special characters must be avoided.

Several ways exist to display bitmap images, pictures so to say, on a screen attached to an Arduino, ESP8266 or ESP32. In the present project we convert a color picture into a c-array that is either included in a sketch or saved in a file that is called from within a sketch. The screen used is a 1.3 inch, 240*240 pixel TFT display with ST7789 controller and SPI interface. Because the file size of a 240*240 color bitmap is way too large to fit program memory in an Arduino Uno we are using an ESP32 microcontroller board: ESP32-WROOM-32. The 1.3”, 240*240 TFT is one of my favorite displays, not only because of its 65,536 available colors (16 bits per pixel, RGB565) but also because of its fast SPI interface which is meticulously supported by Bodmer’s TFT_eSPI.h library.

Compared with current LCD displays and OLED displays, TFT type screens offer the luxury of nearly unlimited color. While it is possible on OLED displays to show pictures, the constraint with this type of display is that pictures are always presented in monochrome. A TFT display shows images as crisp and colorful as your smartphone’s screen does. Of course your smartphone has more pixels than the humble 240*240, which necessitates some cropping and scaling. In this project I started with a big, 2521*1688 pixels jpg image downloaded from Wikipedia.

To possess a TFT screen is one thing, making it work, that is: showing color pictures, needs some investment in ideas, time and effort. As graphical functions are called via a supporting library the selection of a competent library is of prime importance. Another issue is the communication protocol between microcontroller and display. Among the available libraries the TFT_eSPI.h library offers superior support for a variety of controllers / microcontroller board / TFT display configurations, including the configuration used in the current project.

TFT_eSPI can be installed via the Library Manager in the Arduino IDE (Tools → Manage Libraries). Additional Configuration: see section Software. Install the most recent version.

Figure 1 shows the wiring diagram. Wiring is straightforward: the VCC pin of the display breakout board is connected to the 3.3V pin of the ESP32. GND is connected to GND. Of the remaining display pins only four are necessary. Pins marked ‘SCL’ and ‘SDA’ (on other SPI displays sometimes labeled as SCLK and MOSI) are connected to pins D18 and D23 of the ESP32. Pin ‘RES’ on the TFT display is connected to pin D4 of the ESP32, and pin ‘DC’ of the display goes to pin D2 of the ESP32. Pin ‘BLK’ of the TFT is not connected.

The example here, shown in figure 1, is a picture of a ladybug. The image was acquired via a search on Wikipedia. Its credentials are: Gilles San Martin from Namur, Belgium – Coccinella magnifica, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=7694675. The original picture is beautiful, but it is also huge compared with my humble TFT: 2521*1688, format: jpg.

Resulting after all the photo editing was a 173 kB BMP image file (‘ladybug.bmp’) with dimensions 240*240 and in True Color = R5G6B5, 16-bit color depth (64k colors).

Once the proper size, color depth and format had been obtained the moment had arrived to convert the picture into c-array format. This is the format recognized and processed by the Arduino compiler.

A very convenient program to convert BMP image files to c-array format is ‘lcd-image-converter’. This is a Windows program, freely available on the internet. What one needs to do in lcd-image-converter is shown in figures 2 and 3.

First thing to do is to start the program, provide a name for the project (‘ladybug’) and check the conversion parameters. This is done via Options, Conversion. Be sure that Block Size is 16 bit, byte order ‘Little Endian’ (figure 2).

Via ‘File’ and ‘Convert’ the end result is produced: a file named ‘ladybug.c’ (file size here: 638 kb). This file is in ascii format. Its contents can be inspected with an ascii editor (Notepad, Notepad++, Gedit).

0x4b41, 0x4321, 0x4321, 0x4301, 0x42e1, 0x4301, 0x4301, 0x4b41… ……..and so forth until the final pixels……. 0x8ccd, 0x84ad, 0x848c, 0x848c, 0x846c, 0xa571, 0xa571, 0xa571

The essential image c-array data can be placed into a separate file while all data are ‘imported’ at compilation time via a simple ‘include’ instruction inside the sketch. This has the advantage of a clean sketch that is easy to edit. The data file needs to be saved in the same folder as the sketch.

0x4b41, 0x4321, 0x4321, 0x4301, 0x42e1, 0x4301, 0x4301, 0x4b41… ……..and so forth until the final pixels……. 0x8ccd, 0x84ad, 0x848c, 0x848c, 0x846c, 0xa571, 0xa571, 0xa571

This library is extremely versatile, with many graphical functions, while it supports a great number of combinations of microcontroller boards and display controllers. The great difference between TFT_eSPI.h and alternative libraries, e.g. Adafruit_GFX.h and U8glib.h is that the so-called ‘constructor’ is absent.

The idea in TFT_eSPI is that all necessary parameters presented to the library are in a series of instructions bundled in a User_Setup.h file. As its name implies such a file is configurable by the end user. User_Setup.h contains calls to an array of drivers. Look around in the library’s folder named ‘User_Setups’. This folder is a playground for folks who like to experiment with all sorts of microcontrollers and displays. A superb idea!

After experimenting first with breadboards and jumper wires I decided to take a 7×9 cm soldering prototyping board and some pin sockets to solder a small robust bench that accommodates the ESP32-WROOM and the 2402*40 TFT (figure 4). Further software testing was done with this bench. Results were excellent. The TFT_eSPI library supports the ESP32 / ST7789 240*240 SPI TFT without any problem and, very important: very fast. I made and tested a variety of c-array coded images in a range of formats (e.g., 80*160; 128*128 and so on). They were all displayed very well on the small square screen. Condition is that the data file name is 8-character limited. One of these extra images, a picture of a dog called ‘bastien’, was cropped at 240*380 pixels and converted into a c-array (file size of the c-array: 1 MB). The sketch calling this c-array was perfectly compiled. Only the left part of the image was shown on screen with the instruction ‘tft.pushImage (0,0,240,240, bastien);‘, and the same happened when the instruction was changed into ‘ tft.pushImage (0,0,240,380,bastien);‘. This means that the TFT_eSPI library handles images benevolently. The instruction ‘’tft.pushImage (0,0,120,120, bastien);‘ produced an image on the left lower quadrant of the display, and this image contained the left lower quadrant of the bitmap picture.

An interesting option is to place several external c-array.h files into progmem in order to produce a slideshow. I tried this with two 240*240 pixel images of the famous portrait of Che Guevara; one named ‘che-red.h’ and the other ‘che-grey.h’. With a simple delay () instruction a display time between successive images can be set. A series of calls to several more external c-array image files is possible as well. Here the prospect of animation looms. The successful compilation of a 240*380 pixel c-array image tempts me to investigate how far the the envelope of the ESP32 microcontroller can be pushed with images of increasing size. Such a project can easily be entertained on my previously assembled benches that accommodate bigger SPI- or parallel displays (up to 3.95”. 320*480 pixel TFTs *, **). Another attractive project is to use a card reader to transfer images with lightning speed, pixel after pixel, from an image file on SD card to the TFT display.

simple image display for 1.8 tft lcd free sample

The 1.8inch 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.)

ST7735S is a 132*162 pixel LCD, and this product is a 128*160 pixel LCD, so some processing has been done on the display: the display starts from the second pixel in the horizontal direction, and the first pixel in the vertical direction. Start to display, so as to ensure that the position corresponding to the RAM in the LCD is consistent with the actual position when displayed.

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

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

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

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).

Select image buffer: The purpose of the selection is that you can create multiple image attributes, there can be multiple images buffer, you can select each image you create.

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 rectangle: In the image buffer, draw a rectangle from (Xstart, Ystart) to (Xend, Yend), you can choose the color, the width of the line, whether to fill the inside of the rectangle.

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.;

2. The module_init() function is automatically called in the INIT () initializer on the LCD, but the module_exit() function needs to be called by itself

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".

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 demo is developed based on the HAL library. Download the demo, find the STM32 program file directory, and open the LCD_demo.uvprojx in the STM32\STM32F103RBT6\MDK-ARM directory to check the program.

For the screen, if you need to draw pictures, display Chinese and English characters, display pictures, etc., you can use the upper application to do, and we provide some basic functions here about some graphics processing in the directory STM32\STM32F103RB\User\GUI_DEV\GUI_Paint.c(.h)

Select image buffer:the purpose of the selection is that you can create multiple image attributes, image buffer can exist multiple, you can select each image you create.

Image buffer part of the window filling color: the image buffer part of the window filled with a certain color, generally as a window whitewashing function, often used for time display, whitewashing on a second

Draw rectangle: In the image buffer, draw a rectangle from (Xstart, Ystart) to (Xend, Yend), you can choose the color, the width of the line, whether to fill the inside of the rectangle.

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, at (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, 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 GB2312 encoding character font, font foreground color, font background color.

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.

image.cpp(.h): is the image data, which can convert any BMP image into a 16-bit true color image array through Img2Lcd (downloadable in the development data).

Select image buffer:the purpose of the selection is that you can create multiple image attributes, image buffer can exist multiple, you can select each image you create.

Draw rectangle: In the image buffer, draw a rectangle from (Xstart, Ystart) to (Xend, Yend), you can choose the color, the width of the line, whether to fill the inside of the rectangle.

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 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.

Write numbers with decimals: at (Xstart Ystart) as the left vertex, write a string of numbers with decimals, you can choose Ascii code visual character font, font foreground color, font background color

void Paint_DrawFloatNum(UWORD Xpoint, UWORD Ypoint, double Nummber, UBYTE Decimal_Point, sFONT* Font, UWORD Color_Foreground, UWORD Color_Background);

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.

simple image display for 1.8 tft lcd free sample

This is a graphics library for the family of small colour TFT displays based on the ST7735 and ST7789 driver chips. These are really nice displays; bright, colourful, available in a variety of useful sizes, and available at low cost from suppliers like Adafruit, AliExpress, or Banggood:

This library allows you to plot points, draw lines, draw filled rectangles, and plot text with an optional scale factor. I"ve included a demo histogram-plotting program that adjusts itself to fit each of the displays I"ve supported.

Unlike most other TFT display libraries this one doesn"t require a memory buffer, allowing it to be run on any processor down to an ATtiny85. The displays are SPI and require four pins to drive the display, leaving one pin free on an ATtiny85 to interface to another device, such as a temperature sensor. If you need more pins choose a larger chip, such as the ATtiny84; see Using the library with other AVR chips at the end of the article for information about how to convert the code for different chips.

I started developing this library for another project that I hope to write about at a later date; in the meantime I thought it would be useful to write it up as a stand-alone article.

I"ve published a library for a colour OLED display in a previous article: Colour Graphics Library. The main difference between the colour TFT displays and the colour OLED displays is that the TFT displays are not self-illuminating, and so need a backlight; they therefore have a slightly higher power consumption. However, they are exceedingly cheap, and they are available in larger sizes than the colour OLED displays.

I wrote an initial version of this library in uLisp, my Lisp interpreter for microcontrollers, which made it easy to experiment with different approaches. I then converted it to C to run on an ATtiny85. I can publish the uLisp version if anyone"s interested.

This library will work with displays based on the ST7735 which supports a maximum display size of 132 (H) x 162 (V), or the similar ST7789 which supports a maximum display size of 240 (H) x 320 (V).

The display driver interfaces to the displays with the longer side as the vertical dimension, which is why the rectangular displays are usually listed with the longer dimension second. My library allows you to rotate the image for any desired orientation.

All the Adafruit breakout boards for these displays include level-shifting circuitry, so they will work with either 5V or 3.3V microcontroller boards. They also include an SD card socket, if that"s of interest to you. The Adafruit boards have pullups on the backlight and reset pins, so the display will work if you leave these pins unconnected.

The pullup resistor from the display"s CS pin is optional; it holds the chip select high to prevent the display from being affected by the ISP signals while programming the ATtiny85.

The different displays are catered for by six constants which specify the size of the display, the offsets relative to the area supported by the display driver, whether the display is inverted, and the rotation value; for example:

Note that on some displays you may also have to change the xoff or yoff value when rotating the display. For example, to rotate the image on the 240x240 displays by 180° use the settings:

To check or adjust the values for each display I ran this program, which draws a one-pixel border around the display area, and plots an "F" to show the orientation:

The ATtiny85 and other AVR processors supports toggling of one or more bits in a port, so provided you set all the pins to their disabled state at startup, for speed the display access routines can simply toggle the appropriate pins to enable or disable them.

The InitDisplay() routine first defines the four display pins as outputs, and takes the SCK, DC, and CS pins high (inactive). It then sends the essential configuration commands to the display.

The display memory stores 18 bits per pixel: 6 bits per colour. However, you can write to the display in three alternative modes, with 12, 16, or 18 bits per pixel. I chose the 16 bit mode, which assigns 5 bits to red, 6 bits to green, and 5 bits blue. It"s the most convenient one to work with as you simply send two bytes to define the colour of each pixel.

The foreground and background colours are defined by the two global variables fore and back. Initially these are set to 0xFFFF, white, and 0, black, respectively:

To clear the display the ClearDisplay() routine sends the appropriate number of zero bytes. The routine temporarily switches to 12-bit colour mode, which reduces the time to clear the display by 25%:

The library includes basic graphics routines for plotting points and drawing lines. These work on a conventional coordinate system with the origin at lower left. For example, on the 80x160 display:

My first version of PlotChar() plotted characters by calling PlotPoint() for each pixel. However, I then tried the following alternative approach which defines an area of the display using the CASET (Column Address Set) and RASET (Row Address Set) commands, and then sends a stream of the appropriate bytes to define the character. This turned out to be over three times faster!

By default the ATtiny85 runs at 1MHz. Choose Burn Bootloader to set the fuses for 8MHz operation, or your graphics will run rather slowly, then upload the program using ISP (in-system programming).

14th January 2020: Tested the program with the Adafruit 1.3" 240x240 TFT display, and updated the program to correct a problem when rotating the image on that display.

simple image display for 1.8 tft lcd free sample

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