bitmap animation arduino tft lcd quotation

2023-01-03 12:32:11

Displaying a custom image or graphic on a LCD display is a very useful task as displays are now a premium way of providing feedback to users on any project. With this functionality, we can build projects that display our own logo, or display images that help users better understand a particular task the project is performing, providing an all-round improved User Experience (UX) for your Arduino or ESP8266 based project. Today’s tutorial will focus on how you can display graphics on most Arduino compatible displays.

The procedure described in this tutorial works with all color displays supported by Adafruit’s GFX library and also works for displays supported by the TFTLCD library from Adafruit with little modification. Some of the displays on which this procedure works include:

While these are the displays we have, and on which this tutorial was tested, we are confident it will work perfectly fine with most of the other Arduino compatible displays.

For each of the displays mentioned above, we have covered in past how to program and connect them to Arduino. You should check those tutorials, as they will give you the necessary background knowledge on how each of these displays works.

For this tutorial, we will use the 2.8″ ILI9325 TFT Display which offers a resolution of 320 x 340 pixels and we will display a bitmap image of a car.

To demonstrate how things work, we will use the 2.8″ TFT Display. The 2.8″ TFT display comes as a shield which plugs directly into the Arduino UNO as shown in the image below.

Not all Arduino displays are available as shields, so when working with any of them, connect the display as you would when displaying text (we recommend following the detailed tutorial for the display type you use of the above list). This means no special connection is required to display graphics.

Before an image is displayed on any of the Arduino screens, it needs to be converted to a C compatible hex file and that can only happen when the image is in bitmap form. Thus, our first task is to create a bitmap version of the graphics to be displayed or convert the existing image to a bitmap file. There are several tools that can be used for creation/conversion of bitmap images including, Corel Draw and Paint.net, but for this tutorial, we will use the Paint.net.

Your graphics could also include some text. Just ensure the background is black and the fill color is white if you plan to change the color within your Arduino code.

With the graphics done, save both files as .bmp with 24bits color.It is important to keep in mind that large bitmaps use up a lot of memory and may prevent your code from running properly so always keep the bitmaps as small as possible.

Image2Code is an easy-to-use, small Java utility to convert images into a byte array that can be used as a bitmap on displays that are compatible with the Adafruit-GFX or Adafruit TFTLCD (with little modification) library.

All we have to do is to load the graphics into the software by clicking the “Choose file” button and it will automatically generate a byte array equivalent to the selected bitmap file.

Paste the bit array in the graphics.c file and save. Since we have two graphics (the car and the text), You can paste their data array in the same file. check the graphics.c file attached to the zip file, under the download section to understand how to do this. Don’t forget to declare the data type as “const unsigned char“, add PROGEM in front of it and include the avr/pgmspace.h header file as shown in the image below. This instructs the code to store the graphics data in the program memory of the Arduino.

With this done, we are now ready to write the code. Do note that this procedure is the same for all kind of displays and all kind of graphics. Convert the graphics to a bitmap file and use the Img2code utility to convert it into a hex file which can then be used in your Arduino code.

To reduce the amount of code, and stress involved in displaying the graphics, we will use two wonderful libraries; The GFX library and the TFTLCD library from Adafruit.

The GFX library, among several other useful functions, has a function called drawBitmap(), which enables the display of a monochrome bitmap image on the display. This function allows the upload of monochrome only (single color) graphics, but this can be overcome by changing the color of the bitmap using some code.

The Adafruit libraries do not support all of the displays but there are several modifications of the libraries on the internet for more displays. If you are unable to find a modified version of the library suitable for your the display, all you need do is copy the code of the drawBitmap() function from the GFX library and paste it in the Arduino sketch for your project such that it becomes a user-defined function.

The first two are thex and y coordinates of a point on the screen where we want the image to be displayed. The next argument is the array in which the bitmap is loaded in our code, in this case, it will be the name of the car and the text array located in the graphics.c file. The next two arguments are the width and height of the bitmap in pixels, in other words, the resolution of the image. The last argument is the color of the bitmap, we can use any color we like. The bitmap data must be located in program memory since Arduino has a limited amount of RAM memory available.

As usual, we start writing the sketch by including the libraries required. For this procedure, we will use the TFTLCD library alone, since we are assuming you are using a display that is not supported by the GFX library.

Next, we specify the name of the graphics to be displayed; car and title. At this stage, you should have added the bit array for these two bitmaps in the graphics.c file and the file should be placed in the same folder as the Arduino sketch.

With that done, we proceed to the void loop function, under the loop function, we call the drawbitmap() function to display the car and the text bitmap using different colors.

The last section of the code is the drawBitmap function itself, as earlier mentioned, to use the drawbitmap() function with the Adafruit TFTLCD library, we need to copy the function’s code and paste into the Arduino sketch.

Plug in your screen as shown above. If you are using any other display, connect it as shown in the corresponding linked tutorial. With the schematics in place, connect the Arduino board to your PC and upload the code. Don’t forget the graphics file needs to be in the same folder as the Arduino sketch.

That’s it for this tutorial guys. The procedure is the same for all kinds of Arduino compatible displays. If you get stuck while trying to replicate this using any other display, feel free to reach out to me via the comment sections below.

bitmap animation arduino tft lcd quotation

I am messing around with TFT displays now and have been interested in my TFT displays bitmap function, however, it is very slow. when doing any other kind of colour printing/messages it is about as instantaneous as I"d expect, but when doing bitmaps it takes almost 30seconds to fully update the 320x480px screen.

I"m wondering if this is normal for this type of display and setup and if not then, how can I speed it up! Ideally I"d like to display simple animations!

bitmap animation arduino tft lcd quotation

ILI9341 based TFT Touchscreen Display Shields are very popular low cost Display Shields for Arduino. Visuino has had support for them for quite a while, but I never had chance to write a Tutorial on how to use them. Recently however few people asked questions about using displays with Visuino, so I decided to make a tutorial.

In this Tutorial, I will show you how easy it is, to connect the Shield to Arduino, and program it with Visuino to animate a Bitmap to move around on the Display.

In the "Shields" dialog expand the "Displays" category, and select the "TFT Color Touch Screen Display ILI9341 Shield", then click on the "+" button to add it (Picture 2)

Next we need to add Graphics elements to render text and bitmap. First we will add graphics element to draw the shadow of the text:In the Object Inspector, click on the "..." button next to the value of the "Elements" property of the "TFT Display" Element (Picture 1)

Next we will add graphics element to draw the bitmap:In the Elements editor select “Draw Bitmap”, and then click on the "+" button (Picture 1) to add one (Picture 2)

In the Object Inspector, click on the "..." button next to the value of the "Bitmap" property of the "Draw Bitmap1" Element (Picture 2) to open the "Bitmap Editor" (Picture 3)

In the File Open Dialog, select the bitmap to draw, and click on the "Open" button (Picture 4). If the file is too big it may not be able to fit in the Arduino memory. If you get out of memory error during the compilation, you may need to select a smaller bitmap

To animate the Bitmap, we need to control its X and Y position. For this we will add pins for the X and Y properties:In the Object Inspector click on the "Pin" button at front of the "X" property of the "Draw Bitmap1" element (Picture 1), and select "Integer SinkPin" (Picture 2)

In the Object Inspector click on the "Pin" button at front of the "Y" property of the "Draw Bitmap1" element (Picture 3), and select "Integer SinkPin" (Picture 4)

We will use 2 Integer sine generators to animate the bitmap movement:Type "sine" in the Filter box of the Component Toolbox then select the "Sine Integer Generator" component (Picture 1), and drop two of them it in the design area

Add TipAsk QuestionCommentDownloadStep 9: In Visuino: Configure the Second Sine Generator, and Connect the Sine Generators to the X and Y Coordinate Pins of the Bitmap

Connect the "Out" output pin of the SineIntegerGenerator1component to the "X" input pin of the "Shields.TFT Sisplay.Elements.Draw Bitmap1" element of the Arduino component (Picture 4)

Connect the "Out" output pin of the SineIntegerGenerator2component to the "Y" input pin of the "Shields.TFT Display.Elements.Draw Bitmap1" element of the Arduino component (Picture 5)

To render the bitmap every time the X and Y position are updated we need to send a clock signal to the "Draw Bitmap1" element. To send the command after the positions have been changed, we need a way to synchronize the events. For this we will use Repeat component to constantly generate events, and Clock Multi Source to generate 2 events in sequence. The first event will clock the sine generators to update the X and Y positions, and the second will clock the "Draw Bitmap1" :Type "repeat" in the Filter box of the Component Toolbox, then select the "Repeat" component (Picture 1), and drop it in the design area (Picture 2)

Connect the "Pin[ 1 ]" output pin of the "Clock" input pin of the "Shields.TFT Display.Elements.Draw Bitmap1" element of the Arduino component (Picture 6)

Pictures 2, 3, 4 and 5 and the Video show the connected and powered up project. You will see the Bitmap moving around the ILI9341 based TFT Touchscreen Display Shield as seen on the Video.

Also attached is the Visuino project, that I created for this Instructable, and the bitmap with the Visuino logo. You can download and open it in Visuino: https://www.visuino.com

bitmap animation arduino tft lcd quotation

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.

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:

bitmap animation arduino tft lcd quotation

I am using a 3.5: TFT LCD display with an Arduino Uno and the library from the manufacturer, the KeDei TFT library. The library came with a bitmap font table that is huge for the small amount of memory of an Arduino Uno so I"ve been looking for alternatives.

What I am running into is that there doesn"t seem to be a standard representation and some of the bitmap font tables I"ve found work fine and others display as strange doodles and marks or they display upside down or they display with letters flipped. After writing a simple application to display some of the characters, I finally realized that different bitmaps use different character orientations.

What are the rules or standards or expected representations for the bit data for bitmap fonts? Why do there seem to be several different text character orientations used with bitmap fonts?

Are these due to different target devices such as a Windows display driver or a Linux display driver versus a bare metal Arduino TFT LCD display driver?

What is the criteria used to determine a particular bitmap font representation as a series of unsigned char values? Are different types of raster devices such as a TFT LCD display and its controller have a different sequence of bits when drawing on the display surface by setting pixel colors?

Is there some method other than the approach I"m using to determine what transformation is needed? I currently plug the bitmap font table into a test program and print out a set of characters to see how it looks and then fine tune the transformation by testing with the Arduino and the TFT LCD screen.

I"m not fully conversant with the standard descriptions of bitmap fonts however I think of this as being an 8x16 bitmap font in which each character is 8 pixels wide and 16 pixels in height or an 8x16 bitmap font.

With the size of this table and the small amount of memory on the Arduino Uno, I started hunting for other bitmap fonts that would be legible while also taking up less memory. See reducing memory required for KeDei TFT library used with 3.5" TFT display with Arduino

What I hoped to find was something around a 6x6 bitmap font so that the definition of the bitmap font table would change from const unsigned char font_table_16_col[96][16] = { to const unsigned char font_table_16_col[96][6] = { which would free up a significant amount of memory. And experiments with cutting the table down by removing lower case letters showed that helped as well.

Finding alternative bitmap fonts has been more difficult than I thought, envisioning someone with the motherlode of bitmap fonts in a GitHub repository somewhere, easily found with a search or two.

What I have run into is that while I have found several different examples of bitmap fonts not all seem to be compatible with my specific 3.5" TFT LCD display.

For instance here are representations of four different bitmap fonts showing the bits of the bitmaps for two characters, the exclamation point (!) and the double quote ("). The 5x8 seems to be rotated to the clockwise by 90 degrees. The 8x8 and the 16x8 seem to be oriented correctly and the 13x8 seems to be upside down.

The bitmap font representations in the image above, showing the differences in text character orientation, were generated by a simple Windows GUI and displayed with a dash (-) representing a bit value of zero and an asterisk (*) representing a bit value of 1. This is the output of a Microsoft Windows GUI application whose WM_PAINT message handler which draws the displayed image is as follows:

I have modified the code that displays text using the bitmap fonts so that for a particular bit map the character drawing logic will perform several different kinds of translations between the bitmap font representation as a series of hexadecimal digits and how the series of digits are used to determine which pixels to turn on and which to turn off.

The code for drawing a single line of a character is as follows. The outline of this function is to provide to the LCD controller a rectangle specifying the region of the display to be modified followed by a series of two 8 bit writes to set the two byte RGB565 color value of each of the pixels in the region.

static bool TFTLCD::draw_glyph(unsigned short x0, unsigned short y0, TftColor fg_color, TftColor bg_color, unsigned char bitMap, unsigned char bmWidth, unsigned char flags)

and the source code that uses the above function for drawing a complete characters is as follows. This code uses the drawGlyph() function to draw a series of slices of the text character from top to bottom. When a bitmap transformation is done depends on the bitmap representation.

TFTLCD::draw_glyph(Font::now_x, Font::now_y, Font::font_color, Font::txt_backcolor, Font::font_table.table[char_i_x + char_m], Font::font_table.nCols, glyphFlags);

There are a number of font specifications including rasterized bitmap type fonts. These specifications do not necessarily describe the glyph bitmaps used in application such as the KeDei TFT library but rather provide a device independent description of a bitmap font format.

Oracle in Solarix X Window System Developer"s Guide, Chapter 4 Font Support at https://docs.oracle.com/cd/E19253-01/816-0279/6m6pd1cvk/index.html has a table listing several different bitmap font formats and has this to say:

bitmap animation arduino tft lcd quotation

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