arduino code for lcd 2 inch spi tft lcd made in china
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.
As a 2inch IPS display module with a resolution of 240 * 320, it uses an SPI interface for communication. The LCD has an internal controller with basic functions, which can be used to draw points, lines, circles, and rectangles, and display English, Chinese as well as pictures.
The 2inch LCD uses the PH2.0 8PIN interface, which can be connected to the Raspberry Pi according to the above table: (Please connect according to the pin definition table. The color of the wiring in the picture is for reference only, and the actual color shall prevail.)
The example we provide is based on STM32F103RBT6, and the connection method provided is also the corresponding pin of STM32F103RBT6. If you need to transplant the program, please connect according to the actual pin.
The LCD supports 12-bit, 16-bit, and 18-bit input color formats per pixel, namely RGB444, RGB565, and RGB666 three color formats, this demo uses RGB565 color format, which is also a commonly used RGB format.
For most LCD controllers, the communication mode of the controller can be configured, usually with an 8080 parallel interface, three-wire SPI, four-wire SPI, and other communication methods. This LCD uses a four-wire SPI communication interface, which can greatly save the GPIO port, and the communication speed will be faster.
Note: Different from the traditional SPI protocol, the data line from the slave to the master is hidden since the device only has display requirement.
We have carried out the low-level encapsulation, if you need to know the internal implementation can go to the corresponding directory to check, for the reason that the hardware platform and the internal implementation are different
2.We use Dev libraries by default. If you need to change to BCM2835 or WiringPi libraries ,please open RaspberryPi\c\Makefile and modify lines 13-15 as follows:
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.
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 argument is a tuple of four elements. (20,10) is the coordinate value in the upper left corner of the rectangle, and (70,60) is the coordinate value in the lower right corner of the rectangle. Fill =" WHITE" means BLACK inside, and outline="BLACK" means the color of the outline is black.
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.
This module is a 2-inch TFT LCD module with “220×176” resolution and 65K color display. It is suitable for Arduino Uno and Mega2560 development boards, and also supports SD card expansion function. The driver IC is ILI9225.
The 2-inch display is a ready-made shield for Arduino Uno, which can also be placed on the Arduino Mega. The pins of this shield are designed to be easily installed on the Arduino.
my_lcd.Fill_Triangle(x_spec+i*side_len-1,y_spec+(i+1)*h_len-1,x_spec+side_len/2+i*side_len-1,y_spec+i*h_len-1,x_spec+(i+1)*side_len-1,y_spec+(i+1)*h_len-1);
my_lcd.Fill_Triangle(x_spec+i*side_len-1,y_spec+(5-i)*h_len-1,x_spec+side_len/2+i*side_len-1,y_spec+(4-i)*h_len-1,x_spec+(i+1)*side_len-1,y_spec+(5-i)*h_len-1);
my_lcd.Draw_Line(2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24),2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24));
my_lcd.Draw_Rectangle(2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24),2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24));
my_lcd.Draw_Round_Rectangle(2+random(my_lcd.Get_Display_Width()-4),13+random(my_lcd.Get_Display_Height()-26),2+random(my_lcd.Get_Display_Width()-4),13+random(my_lcd.Get_Display_Height()-26),5);
my_lcd.Draw_Triangle(2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24),2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24),2+random(my_lcd.Get_Display_Width()-4),12+random(my_lcd.Get_Display_Height()-24));
my_lcd.Fill_Round_Rectangle(my_lcd.Get_Display_Width()/2-1-72+1, my_lcd.Get_Display_Height()/2-1-45+1, my_lcd.Get_Display_Width()/2-1+72-1, my_lcd.Get_Display_Height()/2-1+45-1,5);
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).
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).
No! For about the price of a familiar 2x16 LCD, you get a high resolution TFT display. For as low as $4 (shipping included!), it"s possible to buy a small, sharp TFT screen that can be interfaced with an Arduino. Moreover, it can display not just text, but elaborate graphics. These have been manufactured in the tens of millions for cell phones and other gadgets and devices, and that is the reason they are so cheap now. This makes it feasible to reuse them to give our electronic projects colorful graphic displays.
There are quite a number of small cheap TFT displays available on eBay and elsewhere. But, how is it possible to determine which ones will work with an Arduino? And what then? Here is the procedure:ID the display. With luck, it will have identifying information printed on it. Otherwise, it may involve matching its appearance with a picture on Google images. Determine the display"s resolution and the driver chip.
Find out whether there is an Arduino driver available. Google is your friend here. Henning Karlsen"s UTFT library works with many displays. (http://www.rinkydinkelectronics.com/library.php?i...)
Download and install the driver library. On a Linux machine, as root, copy the library archive file to the /usr/share/arduino/libraries directory and untar or unzip it.
Load an example sketch into the Arduino IDE, and then upload it to the attached Arduino board with wired-up TFT display. With luck, you will see text and/or graphics.
For prototyping and testing:A solderless breadboard male-to-male jumpers male-to-female jumpers 22 gauge insulated hookup wire, solid Graph paper, for planning and sketching wiring diagrams and layouts
A couple of sets (4 each) of decent rechargeable NIMH AA batteries. Note: Beware of cheap ripoff batteries from Hong Kong. These typically take only a 200 mA charge, and even an "intelligent" charger will not refresh them. Purple, blue, and green ones are suspect -- see picture and ... Link #1Link #2
We"ll begin with a simple one. The ILI9163 display has a resolution of 128 x 128 pixels. With 8 pins in a single row, it works fine with a standard Arduino UNO or with a Mega. The hardware hookup is simple -- only 8 connections total! The library put together by a smart fella, by the name of sumotoy, makes it possible to display text in multiple colors and to draw lines.
Note that these come in two varieties, red and black. The red ones may need a bit of tweaking to format the display correctly -- see the comments in the README.md file. The TFT_ILI9163C.h file might need to be edited.
It is 5-volt friendly, since there is a 74HC450 IC on the circuit board that functions as a level shifter. These can be obtained for just a few bucks on eBay and elsewhere, for example -- $3.56 delivered from China. It uses Henning Karlsen"s UTFT library, and it does a fine job with text and graphics. Note that due to the memory requirement of UTFT, this display will work with a standard UNO only with extensive tweaking -- it would be necessary to delete pretty much all the graphics in the sketch, and just stay with text.
on the far side of the display. It has 220x176 resolution (hires!) and will accept either 3.3 or 5 volts. It will work hooked up to an Uno, and with a few pin changes, also with a Mega. The 11-pin row is for activating the display itself, and the 5-pin row for the SD socket on its back.
This one is a 2.2" (diagonal) display with 176x220 resolution and parallel interface. It has a standard ("Intel 8080") parallel interface, and works in both 8-bit and 16-bit modes. It uses the S6D0164 driver in Henning Karlsen"s UTFT library, and because of the memory requirements of same, works only with an Arduino Mega or Due. It has an SD card slot on its back
This one is a bit of an oddball. It"s a clone of the more common HY-TFT240, and it has two rows of pins, set at right angles to one another. To enable the display in 8-bit mode, only the row of pins along the narrow edge is used. The other row is for the SD card socket on the back, and for 16-bit mode. To interface with an Arduino ( Mega or Due), it uses Henning Karlsen"s UTFT library, and the driver is ILI9325C. Its resolution is 320x240 (hires!) and it incorporates both a touch screen and an SD card slot.
Having determined that a particular TFT display will work with the Arduino, it"s time to think about a more permanent solution -- constructing hard-wired and soldered plug-in boards. To make things easier, start with a blank protoshield as a base, and add sockets for the TFT displays to plug into. Each socket row will have a corresponding row next to it, with each individual hole "twinned" to the adjacent hole in the adjoining row by solder bridges, making them accessible to jumpers to connect to appropriate Arduino pins. An alternative is hard-wiring the socket pins to the Arduino pins, which is neater but limits the versatility of the board.
The key to an effective DIY shield is a neat and logical layout. Sketching the prospective shield on quadrille (graph) paper may be helpful. A multitester or continuity tester might be useful for detecting wiring and soldering errors.
In step 5, you mention that the TFT01 display can"t be used with the UTFT library on an Arduino Uno because of its memory requirements. It can - all you have to do is edit memorysaver.h and disable any display models you"re not using.
I think you should add a disclaimer that the code might make the Arduino Uno unprogrammable afterward (due to use up the two 0 and 1 pin) and link to how to fix it: https://stackoverflow.com/questions/5290428/how-to-reset-an-arduino-board/8453576?sfb=2#84535760
Tho I realize this is quickly becoming legacy hardware, these 8,16 bit parallel spi with 4 wire controller 3.2in Taft touch display 240x380. It has become very inexpensive with ally of back stock world wide so incorporating them into any project is easier then ever. Sorry to my question. I’m having difficulty finding wiring solution for this lcd. It is a sd1289 3.3 and 5v ,40 pin parallel 8,16 bit. I do not want to use a extra shield,hat or cape or adapter. But there’s a lot of conflicting info about required lvl shifters for this model any help or links to info would be great .. thank you. I hope I gave enough information to understand what I’m adoing
#1 you need a data sheet for the display and pinout and the i/o board attached to the cable.Than before you buy check for a driver for this chip Raydium/RM69071.if no driver lib are you able to write one and do you have the necessary tools to work on this scale to wire it up ..if you answer no than search for an arduino ready product.WCH0
hooking up and adding a lib is no piece of cake insure the screen you buy is arduino ready and sold by a reputable shop with step by step directions...WCH0
I"m sorry that I can"t help you with this. You"ll have to do your own research. See if you can identify the chipset and find out if there"s an Arduino driver for it.0
Thanks for the wealth of knowledge! It is amazing at what is possible with items the average person can easily acquire. I hope to put some of your tips to use this winter as I would like to build sensors and other items for home automation and monitoring. Being able to have small displays around the house in addition to gathering and controlling things remotely will help the family see room conditions without going to the computer. The idea of a touchscreen control for cheap is mind blowing.
In this Arduino touch screen tutorial we will learn how to use TFT LCD Touch Screen with Arduino. You can watch the following video or read the written tutorial below.
For this tutorial I composed three examples. The first example is distance measurement using ultrasonic sensor. The output from the sensor, or the distance is printed on the screen and using the touch screen we can select the units, either centimeters or inches.
The next example is controlling an RGB LED using these three RGB sliders. For example if we start to slide the blue slider, the LED will light up in blue and increase the light as we would go to the maximum value. So the sliders can move from 0 to 255 and with their combination we can set any color to the RGB LED, but just keep in mind that the LED cannot represent the colors that much accurate.
The third example is a game. Actually it’s a replica of the popular Flappy Bird game for smartphones. We can play the game using the push button or even using the touch screen itself.
As an example I am using a 3.2” TFT Touch Screen in a combination with a TFT LCD Arduino Mega Shield. We need a shield because the TFT Touch screen works at 3.3V and the Arduino Mega outputs are 5 V. For the first example I have the HC-SR04 ultrasonic sensor, then for the second example an RGB LED with three resistors and a push button for the game example. Also I had to make a custom made pin header like this, by soldering pin headers and bend on of them so I could insert them in between the Arduino Board and the TFT Shield.
Here’s the circuit schematic. We will use the GND pin, the digital pins from 8 to 13, as well as the pin number 14. As the 5V pins are already used by the TFT Screen I will use the pin number 13 as VCC, by setting it right away high in the setup section of code.
As the code is a bit longer and for better understanding I will post the source code of the program in sections with description for each section. And at the end of this article I will post the complete source code.
I will use the UTFT and URTouch libraries made by Henning Karlsen. Here I would like to say thanks to him for the incredible work he has done. The libraries enable really easy use of the TFT Screens, and they work with many different TFT screens sizes, shields and controllers. You can download these libraries from his website, RinkyDinkElectronics.com and also find a lot of demo examples and detailed documentation of how to use them.
After we include the libraries we need to create UTFT and URTouch objects. The parameters of these objects depends on the model of the TFT Screen and Shield and these details can be also found in the documentation of the libraries.
Next we need to define the fonts that are coming with the libraries and also define some variables needed for the program. In the setup section we need to initiate the screen and the touch, define the pin modes for the connected sensor, the led and the button, and initially call the drawHomeSreen() custom function, which will draw the home screen of the program.
So now I will explain how we can make the home screen of the program. With the setBackColor() function we need to set the background color of the text, black one in our case. Then we need to set the color to white, set the big font and using the print() function, we will print the string “Arduino TFT Tutorial” at the center of the screen and 10 pixels down the Y – Axis of the screen. Next we will set the color to red and draw the red line below the text. After that we need to set the color back to white, and print the two other strings, “by HowToMechatronics.com” using the small font and “Select Example” using the big font.
Next is the distance sensor button. First we need to set the color and then using the fillRoundRect() function we will draw the rounded rectangle. Then we will set the color back to white and using the drawRoundRect() function we will draw another rounded rectangle on top of the previous one, but this one will be without a fill so the overall appearance of the button looks like it has a frame. On top of the button we will print the text using the big font and the same background color as the fill of the button. The same procedure goes for the two other buttons.
Now we need to make the buttons functional so that when we press them they would send us to the appropriate example. In the setup section we set the character ‘0’ to the currentPage variable, which will indicate that we are at the home screen. So if that’s true, and if we press on the screen this if statement would become true and using these lines here we will get the X and Y coordinates where the screen has been pressed. If that’s the area that covers the first button we will call the drawDistanceSensor() custom function which will activate the distance sensor example. Also we will set the character ‘1’ to the variable currentPage which will indicate that we are at the first example. The drawFrame() custom function is used for highlighting the button when it’s pressed. The same procedure goes for the two other buttons.
So the drawDistanceSensor() custom function needs to be called only once when the button is pressed in order to draw all the graphics of this example in similar way as we described for the home screen. However, the getDistance() custom function needs to be called repeatedly in order to print the latest results of the distance measured by the sensor.
Here’s that function which uses the ultrasonic sensor to calculate the distance and print the values with SevenSegNum font in green color, either in centimeters or inches. If you need more details how the ultrasonic sensor works you can check my particular tutorialfor that. Back in the loop section we can see what happens when we press the select unit buttons as well as the back button.
Ok next is the RGB LED Control example. If we press the second button, the drawLedControl() custom function will be called only once for drawing the graphic of that example and the setLedColor() custom function will be repeatedly called. In this function we use the touch screen to set the values of the 3 sliders from 0 to 255. With the if statements we confine the area of each slider and get the X value of the slider. So the values of the X coordinate of each slider are from 38 to 310 pixels and we need to map these values into values from 0 to 255 which will be used as a PWM signal for lighting up the LED. If you need more details how the RGB LED works you can check my particular tutorialfor that. The rest of the code in this custom function is for drawing the sliders. Back in the loop section we only have the back button which also turns off the LED when pressed.
In order the code to work and compile you will have to include an addition “.c” file in the same directory with the Arduino sketch. This file is for the third game example and it’s a bitmap of the bird. For more details how this part of the code work you can check my particular tutorial. Here you can download that file:
STONE intelligent TFT LCD module with a Cortex-M4 32-bit CPU can be controlled by any MCU via simple Hex Instruction through the UART port. STONE TFT LCD module consists of a CPU, TFT drives, flash memory, UART port, power supply, etc. STONE also provides a basic control program and powerful design software (STONE TOOL Box).
We have used Liquid Crystal Displays in the DroneBot Workshop many times before, but the one we are working with today has a bit of a twist – it’s a circle! Perfect for creating electronic gauges and special effects.
LCD, or Liquid Crystal Displays, are great choices for many applications. They aren’t that power-hungry, they are available in monochrome or full-color models, and they are available in all shapes and sizes.
Today we will see how to use this display with both an Arduino and an ESP32. We will also use a pair of them to make some rather spooky animated eyeballs!
Waveshare actually has several round LCD modules, I chose the 1.28-inch model as it was readily available on Amazon. You could probably perform the same experiments using a different module, although you may require a different driver.
There are also some additional connections to the display. One of them, DC, sets the display into either Data or Command mode. Another, BL, is a control for the display’s backlight.
Another difference is simply with the labeling on the display. There are two pins, one labeled SDA and the other labeled SCL. At a glance, you would assume that this is an I2C device, but it isn’t, it’s SPI just like the Waveshare device.
This display can be used for the experiments we will be doing with the ESP32, as that is a 3.3-volt logic microcontroller. You would need to use a voltage level converter if you wanted to use one of these with an Arduino Uno.
The Arduino Uno is arguably the most common microcontroller on the planet, certainly for experiments it is. However, it is also quite old and compared to more modern devices its 16-MHz clock is pretty slow.
The Waveshare device comes with a cable for use with the display. Unfortunately, it only has female ends, which would be excellent for a Raspberry Pi (which is also supported) but not too handy for an Arduino Uno. I used short breadboard jumper wires to convert the ends into male ones suitable for the Arduino.
Once you have everything hooked up, you can start coding for the display. There are a few ways to do this, one of them is to grab the sample code thatWaveshare provides on their Wiki.
The Waveshare Wiki does provide some information about the display and a bit of sample code for a few common controllers. It’s a reasonable support page, unfortunately, it is the only support that Waveshare provides(I would have liked to see more examples and a tutorial, but I guess I’m spoiled by Adafruit and Sparkfun LOL).
Open the Arduino folder. Inside you’ll find quite a few folders, one for each display size that Waveshare supports. As I’m using the 1.28-inch model, I selected theLCD_1inch28folder.
Once you do that, you can open your Arduino IDE and then navigate to that folder. Inside the folder, there is a sketch file namedLCD_1inch28.inowhich you will want to open.
When you open the sketch, you’ll be greeted by an error message in your Arduino IDE. The error is that two of the files included in the sketch contain unrecognized characters. The IDE offers the suggestion of fixing these with the “Fix Encoder & Reload” function (in the Tools menu), but that won’t work.
The error just seems to be with a couple of the Chinese characters used in the comments of the sketch. You can just ignore the error, the sketch will compile correctly in spite of it.
The code is pretty basic, I’m not repeating all of it here, as it consists of several files. But we can gather quite a bit of knowledge from the main file, as shown here.
You can see from the code that after loading some libraries we initialize the display, set its backlight level (you can use PWM on the BL pin to set the level), and paint a new image. We then proceed to draw lines and strings onto the display.
Unfortunately, Waveshare doesn’t offer documentation for this, but you can gather quite a bit of information by reading theLCD_Driver.cppfile, where the functions are somewhat documented.
After uploading the code, you will see the display show a fake “clock”. It’s a static display, but it does illustrate how you can use this with the Waveshare code.
This library is an extension of the Adafruit GFX library, which itself is one of the most popular display libraries around. Because of this, there isextensive documentation for this libraryavailable from Adafruit. This makes the library an excellent choice for those who want to write their own applications.
Here is the hookup for the ESP32 and the GC9A01 display. As with most ESP32 hookup diagrams, it is important to use the correct GPIO numbers instead of physical pins. The diagram shows the WROVER, so if you are using a different module you’ll need to consult its documentation to ensure that you hook it up properly.
The TFT_eSPI library is ideal for this, and several other, displays. You can install it through your Arduino IDE Library Manager, just search for “TFT_eSPI”.
There is a lot of demo code included with the library. Some of it is intended for other display sizes, but there are a few that you can use with your circular display.
To test out the display, you can use theColour_Test sketch, found inside the Test and Diagnostic menu item inside the library samples. While this sketch was not made for this display, it is a good way to confirm that you have everything hooked up and configured properly.
A great demo code sample is theAnimated_dialsketch, which is found inside theSpritesmenu item. This demonstration code will produce a “dial” indicator on the display, along with some simulated “data” (really just a random number generator).
In order to run this sketch, you’ll need to install another library. Install theTjpeg_DecoderLibrary from Library Manager. Once you do, the sketch will compile, and you can upload it to your ESP32.
The first thing we need to do is to hook up a second display. To do this, you connect every wire in parallel with the first display, except for the CS (chip select) line.
The Animated Eyes sketch can be found within the sample files for the TFT_eSPI library, under the “generic” folder. Assuming that you have wired up the second GC9A01 display, you’ll want to use theAnimated_Eyes_2sketch.
The GC9A01 LCD module is a 1.28-inch round display that is useful for instrumentation and other similar projects. Today we will learn how to use this display with an Arduino Uno and an ESP32.
Looking through the different Nextion user groups on social networks, the Nextion user forum and a few not so official but Nextion related forums can be surprising. Sometimes, Nextion newbies ask questions or have issues although the required function is well (in a condensed manner for the experienced developer, I admit) documented on the Nextion Instruction Set page, accessible through the menu of this website. On top of that, there is for sure one of my more than 100 Sunday blog articles which deals not only with that function, but goes often even beyond the usual usage of it. Apparently, I should sometimes move away from always trying to push the limits and listen to the "back to the roots!" calls by my potential readers...Do you remember the (almost) full screen sized flicker free and ultra rapid gauge we designed in June? And this without using the built-in Gauge component? If not, it"s time to read this article first, to understand today"s improvements. The June 2022 version does its job perfectly, the needle movement is quick and smooth, and other components can be added close to the outer circle without flickering since there is no background which needs constantly to be redrawn. But there was a minor and only esthetic weak point: The needle was a 1px thin line, sometimes difficult to see. Thus, already a short time after publishing, some readers contacted me and asked if there were a way to make the needle thicker, at least 2 pixels.Recently, when playing with a ESP32 based NodeMCU 32S and especially with its WiFi configuration, I did as (I guess) everybody does: I loaded an example sketch to learn more about the Wifi library. When you set up the ESP32 as an access point, creating its own wireless network, everything is pretty straightforward. You can easily hard code the Wifi name (SSID) and the password. But what about the client mode ? Perhaps one needs to use it in different environments. And then, a hard coded network name and password are definitively not the best solution. Thus, I thought, why not use a Nextion HMI for a dynamic WiFi setup functionality?Although the Nextion MIDI I/O interface has been primarily designed as an add-on for Nextion HMI screens to transform these in fully autonomous MIDI devices as shown in previous blog posts here, it is also of great use for any Arduino based electronic music project! Many MIDI projects for Arduino suffer from a lack good hardware support. There are sophisticated code, excellent libraries and an infinity of use cases, but afterwards, things tend not to work in a rather rough environment in the studio or on stage. That"s because two resistors and a few Dupont wires on a breadboard besides the Arduino are not really an interface which could drive your Synth, Sequencer, or Drum machine over a 5m long MIDI cable.First of all, let"s open a virtual bottle of Champaign - this is my 100st Sunday Blog post!!! Now, let"s celebrate this with a new functionality: Have your Nextion HMI computing square roots with just 21 lines of code and 5 integer variable components, everything nicely packed in a ready-to-use page template - the Nextion equivalent of a library as seen over the last weeks. The advantage is that you can add this function to a page by designing the latter by starting with importing the appropriate template and then customizing it as you would any other page of your project. And if your project doesn"t need it - let it away and save memory! In my humble opinion, that"s a way more interesting solution than requesting the integration of everything into the firmware, with all the runtime memory constraints.Did you ever see the need to increment or decrement values, for example on a settings screen? Did you want to avoid multiple clicks and would have preferred just keeping a button pressed while the value would continue to increment or decrement? And which would go at a higher speed when pressing the button for a longer time? After reading this article, you"ll know how to do that with your beloved Nextion HMI! And no, there is NO need to add to the event code of each button! Only 4 invisible components and less than 20 lines of code are required to transform all buttons on a page into repeater buttons. That is so compact that we"ll pack these into a single page template and export it. From then on, if you need buttons with accelerated auto-repeat on a page, go to the page pane, but instead of adding a blank page, import the template and you are done. Automatically, without an additional line of code, all buttons will magically have the repeat functionality!
Arduino has always helped to build projects easily and make them look more attractive. Programming an LCD screen with touch screen option might sound as a complicated task, but the Arduino libraries and shields had made it really easy. In this project we will use a 2.4” Arduino TFT LCD screen to build our own Arduino Touch Screen calculator that could perform all basic calculations like Addition, Subtraction, Division and Multiplication.
Before we actually dive into the project it is important to know, how this 2.4” TFT LCD Module works and what are the types present in it. Let us take a look at the pinouts of this 2.4” TFT LCD screen module.
As you can see there are 28 pins which will perfectly fit into any Arduino Uno / Arduino Mega Board. A small classification of these pins is given in the table below.
As you can see the pins can be classified in to four main classifications such as LCD Command Pins, LCD Data Pins, SD Card Pins and Power Pins, We need not know much about the detailed working of these pins since they will be take care by our Arduino Library.
You can also find an SD card slot at the bottom of the module shown above, which can be used to load an SD card with bmp image files, and these images can be displayed in our TFT LCD screen using the Arduino Program.
Another important thing to note is your Interface IC. There are many types of TFT modules available in the market starting from the original Adafruit TFT LCD module to cheap Chinese clones. A program which works perfectly for your Adafruit shield might not work the same for Chinese breakout boards. So, it is very important to know which types of LCD display your are holding in hand. This detail has to be obtained from the vendor. If you are having a cheap clone like mine then it is most probably using the ili9341 driver IC.You can follow this TFT LCD interfacing with Arduino tutorial to try out some basic example programs and get comfortable with the LCD screen. Also check out our other TFT LCD projects with Arduino here:
If you planning to use the touch screen function of your TFT LCD module, then you have to calibrate it to make it work properly. A LCD screen without calibration might work unlikely, for instance you might touch at one place and the TFT might respond for a touch at some other place. These calibrations results will not be similar for all boards and hence you are left on your own to do this.
The best way to calibrate is to use the calibration example program (comes with library) or use the serial monitor to detect your error. However for this project since the size of buttons is large calibration should not be a big problem and I will also explain how you can calibrate your screen under the programming section below.
The 2.4” TFT LCD screen is a perfect Arduino Shield. You can directly push the LCD screen on top of the Arduino Uno and it will perfectly match with the pins and slid in through. However, as matters of safety cover the Programming terminal of your Arduino UNO with a small insulation tape, just in case if the terminal comes in contact with your TFT LCD screen. The LCD assembled on UNO will look something like this below.
We are using the SPFD5408 Library to get this arduino calculator code working. This is a modified library of Adafruit and can work seamlessly with our LCD TFT Module. You can check the complete program at the end of this Article.
Now, open Arduino IDE and select Sketch -> Include Librarey -> Add .ZIP library. A browser window will open navigate to the ZIP file and click “OK”. You should notice “Library added to your Libraries” on the bottom-left corner of Arduino, if successful. A detailed guide to do the same is given in the Interfacing Tutorial.
Now, you can use the code below in your Arduino IDE and upload it to your Arduino UNO for the Touch Screen Calculator to work. Further down, I have explained the code into small segments.
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 said earlier we need to calibrate the LCD screen to make it work as expected, but don’t worry the values given here are almost universal. The variables TS_MINX, TS_MINY, TS_MAXX, and TS_MAXY decide the calibration of the Screen. You can toy around them if you feel the calibration is not satisfactory.
As we know the TFT LCD screen can display a lot of colours, all these colours have to be entered in hex value. To make it more human readable we assign these values to a variable as shown below.
Since we have designed the box with width and height of 60 pixel each and have four Rows and for columns starting from (0,0). The position of each box can be predicted as shown in below picture.
Now, since we know the position of all the boxes. When a user touches anywhere we can predict where he has touched by comparing his (X,Y) values with the value for each box as shown below.
The final step is to calculate the result and display them on TFT LCD Screen. This arduino calculator can perform operation with 2 numbers only. These two numbers are named as variables “Num1” and “Num2”. The variable “Number” gives and takes value from Num1 and Num2 and also bears the result.
When a use presses a button, one digit is added to number. When another button is pressed, the previous one digit is multiplied with 10 and the new number is added with it. For example, if we press 8 and then press 5 and then press 7. Then first the variable will hold 8 then (8*10)+5=85 then (85*10)+7 = 857. So finally the variable will have the value 857 with it.
When we perform any operation like addition, when the users presses the addition button the value from Number will be transferred to Num1 and then Number will be made zero so that it gets ready to take the input for second number.
When Equal is pressed the value in Number will be sent to Num2 and then the respective calculation (in this case addition) will be made and the result will be again stored in the variable “Number”.
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.
Now, you can enter any number and perform your calculations. It is limited to only two operand and only operator for now. But, you can tweak the code to make it have lots of option.
You have to press the “C” to clear the value on screen each time after performing a calculation. Hope you understood the project and enjoyed building something similar. If you have any doubts feel free to post them on forums or on the comment section below. See you next time with another interesting project until then happy computing!!
The Arduino board has a wide variety of compatible displays that you can use in your electronic projects. In most projects, it’s very useful to give the user some sort of feedback from the Arduino.
With the TFT display you can display colorful images or graphics. This module has a resolution of 480 x 320. This module includes the SD card socket and SPI FLASH circuit.
This is a tiny display with just 1 x 0.96 Inch. This display has a black background, and displays characters in white. There are other similar displays that can show the characters in other colors.
Checking a TFT lcd driver is very messy thing especially if its a Chinese manufactured TFT. TFT’s that are supplied by Chinese manufactures are cheap and every body loves to purchase them since they are cheap,but people are unaware of the problems that comes in future when finding the datasheet or specs of the particular TFT they purchased. Chinese manufactures did not supply datasheet of TFT or its driver. The only thing they do is writes about the TFT driver their lcd’s are using on their websites. I also get in trouble when i started with TFT’s because i also purchased a cheap one from aliexpress.com. After so many trials i succeeded in identifying the driver and initializing it. Now i though to write a routine that can identify the driver.
I wrote a simple Arduino Sketch that can easily and correctly identify the TFT Lcd driver. I checked it on 2.4, 3.2 and 3.8 inch 8-bit TFT lcd and it is identifying the drivers correctly. The drivers which i successfully recognized are ILI9325, ILI9328, ILI9341, ILI9335, ST7783, ST7781 and ST7787. It can also recognize other drivers such as ML9863A, ML9480 and ML9445 but i don’t have tft’s that are using this drivers.
The basic idea behind reading the driver is reading the device ID. Since all the drivers have their ID’s present in their register no 0x00, so what i do is read this register and identify which driver tft is using. Reading the register is also a complex task, but i have gone through it many times and i am well aware of how to read register. A simple timing diagram from ST7781 driver explains all. I am using tft in 8-bit interface so i uploaded timing diagram of 8-bit parallel interface. The diagram below is taken from datasheet of ST7781 tft lcd driver.
The most complex tft i came across is from a Chinese manufacturer “mcufriend”. mcufriend website says that they use ILI9341 and ILI9325 drivers for their tft’s. But what i found is strange their tft’s are using ST7781 driver(Device ID=7783). This is really a mesh. I have their 2.4 inch tft which according to their website is using ILI9341 driver but i found ST7783 driver(Device ID=7783). The tft i have is shown below.
I am using Arduino uno to read driver. I inserted my lcd on arduino uno and read the driver. After reading driver i am printing its number on Serial Monitor.
Note:On serial monitor driver number will be displayed like if your lcd is using ST7783 controller than on serial monitor 7783 will be displayed or if tft is using ILI9341 than on 9341 will be displayed.
The code works on Arduino uno perfectly but if you are using any other board, than just change the pin numbers according to the board that you are using also check out for the Ports D and B. TFT Data Pin D0 is connected to Port-B Pin#0 and D1 is connected to Port-B Pin#1. TFT Data Pins D2 to D7 are connected to Port-D Pins 2,3,4,5,6,7. So if you are using Arduino mega than check for the Ports D and B and Make connections according to them. Arduino mega is working on ATmega2560 or ATmega1280 Microcontroller and Arduino uno is working on ATmega328p Microcontroller so both platforms have ports on different locations on arduino board so first check them and then make connections. The same process applies to all Arduino boards.