serial lcd screen free sample

The Serial LCD Kit includes all the parts you need to add a serial "backpack" to a 16x2 LCD. The kit includes a pre-programmed ATmega328 microprocessor, which reads a serial stream of data and (after a little heavy-lifting) instantly displays it on the LCD. Interfacing the Serial LCD with an Arduino, or other serial-enabled devices, allows you to easily print GPS coordinates, short messages or any other information onto the LCD.

This tutorial will cover everything you need to know to get up and running with the Serial Enabled LCD Kit. We"ll first go over assembly so you can turn that bag-o-parts into something that hopefully resembles any pictures you may have seen of the kit.

Following assembly, we"ll touch on how to actually use the Serial LCD Kit. Specifically, we"ll go over how you"d use the thing with everybody"s favorite development board, Arduino. There"ll be example code galore, and you can even make your own LCD clock! It"s gonna be pretty crazy...

Finally, you"ll need something to send a serial stream of data to the display. An Arduino works great (any variety, this isn"t limited to the Uno) if you want to automate the serial data stream. FTDI breakouts or RS-232 level shifters work if you just want to connect the display to your computer and send data via a terminal program. For what it"s worth, this tutorial will focus on connecting the display to an Arduino.

The goal of the Serial LCD Kit is to make controlling an LCD simple and to make wiring to it even simpler. If you wanted, you could abstain from using the serial backpack and wire an Arduino directly up to the LCD. To that point, there are loads of great examples, and even some Arduino libraries, that make interfacing a microcontroller directly to an LCD very easy. However, because the LCD is driven by a parallel interface, those examples require a tangle of wires and anywhere from 6 to 11 pins of the Arduino to control the thing.

The microcontroller on the Serial LCD Kit takes care of all of that nasty wiring, so you only need one pin to control the LCD. The Serial LCD"s on-board microcontroller parses any incoming commands or characters, and then sends the proper data to the LCD over the multi-wire parallel interface. It"s a magic black box, and you don"t have to care how it does its job, just that it does it. So let"s get it built...

What you"ve got in front of you right now is not yet a Serial LCD Kit. First, we"ve got to turn that bag of parts into a Serial LCD Kit, which will require soldering. If you"ve never soldered before, don"t fret! This is one of the easier soldering projects, every part is through-hole, and well-spaced. If this is your first time though, I"d encourage you to take a trip over to one of our excellent soldering tutorials before picking up the iron.

First, pick out the big, ferrari-red PCB. See how one side has white silkscreen printed onto it? This is the top of the PCB. You"ll stick almost every part in on this side and solder the pins to the opposite side. The only time we"ll stray from that is when soldering the LCD, which is the last step.

Wait...something"s missing...oh, hi LCD! To connect the LCD to the PCB, we"ve included a straight 16-pin header with the kit. You"ll need to solder this header to both the PCB and the LCD. Solder it first to the LCD, stick the shorter pins into the LCD. Make sure the longer legs are extended out from the back of the LCD and solder all 16-pins on the top side of the LCD. Effort to keep the pins as perpendicular to the LCD as possible.

With the header soldered to the LCD,you"ll finally be able to connect the display to the PCB. Remember, we"re sticking this part into the bottom side of the PCB, and soldering to the top. Solder up all 16 pins, and that should be it.

Before you can display anything on the LCD, you"ll have to connect something to it. Only three wires are necessary to use the Serial LCD Kit: RX, GND and VCC. Plug the included 3-wire jumper cable into its mating JST connector that you soldered onto the PCB. This color coded cable has two wires for power, and one for receiving serial data. The red and black wires correspond to +5V and GND, respectively, and the yellow wire is RX.

You"ll need to figure out how you"re going to powerthe LCD Kit. It doesn"t have a regulator on-board, so it"s up to you to supply a clean, regulated 5V power source. If you"re using an Arduino, you could power the Kit off of the 5V and GND pins – connect red to 5V and black to GND. Otherwise, there"s a ton of options out there for power; you could use a USB adapter, a 5V wall-wart, a breadboard power supply. The list just goes on. Just make sure you"re not supplying any more than 5V (a little less may work, but you"ll lose some brightness).

After powering the Serial LCD Kit, you should notice the backlight turn on. If the contrast is properly adjusted, you might see the splash screen flash for a second or two. Most likely though, the contrast won"t be set correctly, so you won"t see a splash screen. In that case, you may see anything from 32 white boxes to absolutely nothing. You"ll have to be quick about it, because the splash screen only remains for a couple seconds before going blank, but try turning the trimpot knob until you"ve got a good view of the characters on the LCD.

The "Serial" in the Serial LCD Kit can be a little confusing. What it really means is TTL serial, not to be confused with RS-232 serial. The voltage on the RX line should only go between 0 and +5V. If you"re using a microcontroller (like an Arduino) to talk with the LCD, then you most likely don"t have to worry. Just don"t hook up a PC"s serial port straight to the LCD and expect it to survive.

There"s a lot of components that are capable of sending TTL serial data. The most popular here at SparkFun are USB-to-Serial boards (like the FTDI Basic Breakout), or an Arduino. This tutorial is going to assume you have an Arduino for the next few examples. No Arduino? That"s cool. I get it; you"re not gonna conform to this passing fad. Feel free to read on, and try to port these examples to your platform.

Connect the Arduino to the Serial LCD as follows. If you have a wire stripper, you may want to expose a few millimeters more of wire to allow them to stick really nicely into the Arduino"s headers.

Here"s a simple example sketch, which uses the SoftwareSerial library (which is included with recent versions of Arduino) to instill our Arduino with more than just the one, hardware, serial port. Now we can use the hardware serial port to listen to the serial monitor, and the second serial port can be used to talk to the LCD.

Now, plug in your Arduino and upload the code. Open up the serial monitor, and make sure it"s set to 9600. Type “Hello, world” into the serial monitor and send it over to the Arduino. The LCD should echo your greeting. Take the LCD for a test drive, discover all the characters it can display!

You"ll quickly notice, that the code is severely lacking any sort of clear display command, but don"t think for a second that the Serial LCD Kit doesn"t have a clear display command. It"s got commands up the wazoo! The Serial LCD Kit is set up to accept commands that control the backlight, baud rate, and all sorts of display functionality, like clearing the screen. Have a look at the Kit"s “datasheet”, which lists all of the characters and commands you can send to the display. I wrote that, but I understand if it"s all gobbledygook to you right now.

The commands are divided into three groups: backlight, baud rate, and special commands. Each command requires that you send at least two bytes to the display. For instance to set the backlight, you first have to send the backlight control byte (0x80, or decimal 128) followed by a byte with any value from 0 to 255. Sending a 0 will turn the backlight completely off, 255 will turn it all the way on, 127 will set it to about 50%, and so on. The backlight setting is stored in the Serial LCD Kit"s memory and will be restored when the LCD is turned off and on.

What we really care about right now, though, is clearing the display, which requires a special command. To issue a special command to the LCD, you first have to send 0xFE (or decimal 254) which tells the display to go into special command mode, and wait for a data byte. The clear display command is 0x01 (or decimal 1), that command should be sent immediately after sending the special command byte. So to clear the display we need to send two bytes: 254 (0xFE) followed by 1 (0x01). Check out the datasheet link for all of the special commands. You can do all sorts of fun stuff: scroll the display, turn it on/off and control the cursor.

Our next piece of example code, Serial_LCD_Kit_Clock, delves into sending special commands to the LCD with an Arduino. There are individual functions that clear the display (clearDisplay()), set the backlight (setBacklight(byte brightness)), and set the cursor (setLCDCursor(byte cursor_position)), feel free to copy these and add them to any code you"d like.

Now then, that should be enough to get you on your way to using the Serial LCD Kit with a serial interface. If you"re happy with that, and don"t want your mind blown, I suggest you stop reading here.

Oh, you"ve taken the red pill? Well then you get to learn the Serial LCD Kit"s very deep, dark secret. It may not look anything like one, but the LCD Kit is actually Arduino-compatible. It has an ATmega328, just like the Arduino, and that ATmega328 has a serial bootloader, just like an Arduino. It can be programmed via a USB-to-Serial board. This means you can hook up all sorts of sensors, blinkies and other I/O to the Kit itself, while continuing to use the LCD to display any info you"d like. The 6-pin serial programming port on the right hand side of the PCB can be connected to an FTDI Basic Breakout.

With the FTDI board connected, and Arduino open, simply select the corresponding COM port in the Tools>Serial Port menu, and select Arduino Duemilanove or Nano w/ ATmega328 under the Tools>Boards menu. Though it probably won"t look like it"s doing anything, try uploading Blink, change the LED pin to 9 to at least see the backlight of the LCD flick on and off. Remember, you can download the Serial LCD Kit firmware here. If you ever want to turn it back into a Serial LCD, upload it to the LCD like you would any sketch.

If you want to be really adventurous, and get the most out of the Serial LCD Kit, I"d recommend first taking a trip over to where the Serial LCD Kit"s source code is hosted and getting a good idea how the code works. That firmware is written as an Arduino sketch, and uses a great little Arduino library named LiquidCrystal to control the LCD. The LiquidCrystal library makes controlling the LCD with an Arduino super-simple.

You should also get a good feeling for the kit"s schematic. There are a few Arduino pins that can only be used with the LCD (4-9), but pins 10-13, and all of the analog pins can be used with any device you"d normally connect to an Arduino. The available pins are all broken out on the bottom of the PCB.

Remember, this part is all very extracurricular. Don"t feel at all required to use your Serial LCD Kit as an Arduino. I just wanted to let you know what"s possible with this kit.

Serial LCD Clock Example Sketch - Displays a digital clock on the Serial LCD. This is a good example of how to use special commands, like clear, with the display.

Now I"ll leave you and your Serial LCD Kit in peace. I hope you"ve learned a good amount about the display. I also hope you"re left with questions and ideas about what you"re going to do with it next. If you"ve still got questions about the display, or comments about the tutorial, please drop them in the comments box below or email us.

Warning: Arduino and other systems with bootloaders may send "garbage" characters to the display while the system is starting up or being reprogrammed. This may cause the display to be bricked. To avoid this, you can use a software serial library to create a separate serial port from the USB port, as in the following examples. For more information about the library, head over to the reference:

For simplicity, we will be using an Arduino microcontroller. In this example, we connected a serial enabled LCD to the RedBoard programmed with Arduino (basically an Arduino Uno with an ATmega328P).

When you power up the board, you"ll briefly see a SparkFun splash screen, and then the display will go blank. To send text to the board, wait 1/2 second (500ms) after power up for the splash screen to clear, then send text to the display through your serial port. The display understands all of the standard ASCII characters (upper and lowercase text, numbers, and punctuation), plus a number of graphic symbols and Japanese characters. See the HD44780 datasheet for the full list of supported characters.

A common LCD technique is to repeatedly display changing numbers such as RPM or temperature in the same place on the display. You can easily do this by moving the cursor before sending your data.

To move the cursor, send the special character (0xFE), followed by the cursor position you"d like to set. Each cursor position is represented by a number, see the table below to determine the number in decimal to send for a serial enabled LCD set to 16x2:

Do you need a serial LCD display? Our graphic serial LCDs and serial character LCD modules can connect and communicate with almost any host system (microcontrollers, microprocessors, PCs, etc.) and make it easier than ever to include an LCD in your product design.

The Parallax Serial LCDs (liquid crystal displays) can be easily connected to and controlled by a microcontroller using a simple serial protocol sent from a single I/O pin. The LCD displays provide basic text wrapping so that your text looks correct on the display. Full control over all of their advanced LCD features allows you to move the cursor anywhere on the display with a single instruction and turn the display on and off in any configuration. They support visible ASCII characters Dec 32-127). In addition, you may define up to eight of your own custom characters to display anywhere on the LCD. An onboard piezospeaker provides audible output, with full control over tone note, scale and duration using ASCII characters Dec 208–232.

The LCDs currently for sale are updated to Revision F. Basic functionality remains the same, but power requirements and the layout of the backpack have changed. Please see the documentation for information on your model.

This device can be connected to a PC serial port using a MAX232 line driver. The circuit isn’t supported by Parallax, but it’s possible to make this connection with a few extra parts.

As we all know, though LCD and some other displays greatly enrich the man-machine interaction, they share a common weakness. When they are connected to a controller, multiple IOs will be occupied of the controller which has no so many outer ports. Also it restricts other functions of the controller. Therefore, LCD1602 with an I2C bus is developed to solve the problem.

I2C bus is a type of serial bus invented by PHLIPS. It is a high performance serial bus which has bus ruling and high or low speed device synchronization function required by multiple-host system. The blue potentiometer on the I2C LCD1602 (see the figure below) is used to adjust the backlight for better display. I²C uses only two bidirectional open-drain lines, Serial Data Line (SDA) and Serial Clock Line (SCL), pulled up with resistors. Typical voltages used are +5 V or +3.3 V although systems with other voltages are permitted.

In this tutorial, I’ll explain how to set up an LCD on an Arduino and show you all the different ways you can program it. I’ll show you how to print text, scroll text, make custom characters, blink text, and position text. They’re great for any project that outputs data, and they can make your project a lot more interesting and interactive.

The display I’m using is a 16×2 LCD display that I bought for about $5. You may be wondering why it’s called a 16×2 LCD. The part 16×2 means that the LCD has 2 lines, and can display 16 characters per line. Therefore, a 16×2 LCD screen can display up to 32 characters at once. It is possible to display more than 32 characters with scrolling though.

The code in this article is written for LCD’s that use the standard Hitachi HD44780 driver. If your LCD has 16 pins, then it probably has the Hitachi HD44780 driver. These displays can be wired in either 4 bit mode or 8 bit mode. Wiring the LCD in 4 bit mode is usually preferred since it uses four less wires than 8 bit mode. In practice, there isn’t a noticeable difference in performance between the two modes. In this tutorial, I’ll connect the LCD in 4 bit mode.

Here’s a diagram of the pins on the LCD I’m using. The connections from each pin to the Arduino will be the same, but your pins might be arranged differently on the LCD. Be sure to check the datasheet or look for labels on your particular LCD:

Also, you might need to solder a 16 pin header to your LCD before connecting it to a breadboard. Follow the diagram below to wire the LCD to your Arduino:

Now we’re ready to get into the programming! I’ll go over more interesting things you can do in a moment, but for now lets just run a simple test program. This program will print “hello, world!” to the screen. Enter this code into the Arduino IDE and upload it to the board:

There are 19 different functions in the LiquidCrystal library available for us to use. These functions do things like change the position of the text, move text across the screen, or make the display turn on or off. What follows is a short description of each function, and how to use it in a program.

TheLiquidCrystal() function sets the pins the Arduino uses to connect to the LCD. You can use any of the Arduino’s digital pins to control the LCD. Just put the Arduino pin numbers inside the parentheses in this order:

This function sets the dimensions of the LCD. It needs to be placed before any other LiquidCrystal function in the void setup() section of the program. The number of rows and columns are specified as lcd.begin(columns, rows). For a 16×2 LCD, you would use lcd.begin(16, 2), and for a 20×4 LCD you would use lcd.begin(20, 4).

This function clears any text or data already displayed on the LCD. If you use lcd.clear() with lcd.print() and the delay() function in the void loop() section, you can make a simple blinking text program:

This function places the cursor in the upper left hand corner of the screen, and prints any subsequent text from that position. For example, this code replaces the first three letters of “hello world!” with X’s:

Similar, but more useful than lcd.home() is lcd.setCursor(). This function places the cursor (and any printed text) at any position on the screen. It can be used in the void setup() or void loop() section of your program.

The cursor position is defined with lcd.setCursor(column, row). The column and row coordinates start from zero (0-15 and 0-1 respectively). For example, using lcd.setCursor(2, 1) in the void setup() section of the “hello, world!” program above prints “hello, world!” to the lower line and shifts it to the right two spaces:

You can use this function to write different types of data to the LCD, for example the reading from a temperature sensor, or the coordinates from a GPS module. You can also use it to print custom characters that you create yourself (more on this below). Use lcd.write() in the void setup() or void loop() section of your program.

The function lcd.noCursor() turns the cursor off. lcd.cursor() and lcd.noCursor() can be used together in the void loop() section to make a blinking cursor similar to what you see in many text input fields:

Cursors can be placed anywhere on the screen with the lcd.setCursor() function. This code places a blinking cursor directly below the exclamation point in “hello, world!”:

This function creates a block style cursor that blinks on and off at approximately 500 milliseconds per cycle. Use it in the void loop() section. The function lcd.noBlink() disables the blinking block cursor.

This function turns on any text or cursors that have been printed to the LCD screen. The function lcd.noDisplay() turns off any text or cursors printed to the LCD, without clearing it from the LCD’s memory.

This function takes anything printed to the LCD and moves it to the left. It should be used in the void loop() section with a delay command following it. The function will move the text 40 spaces to the left before it loops back to the first character. This code moves the “hello, world!” text to the left, at a rate of one second per character:

Like the lcd.scrollDisplay() functions, the text can be up to 40 characters in length before repeating. At first glance, this function seems less useful than the lcd.scrollDisplay() functions, but it can be very useful for creating animations with custom characters.

lcd.noAutoscroll() turns the lcd.autoscroll() function off. Use this function before or after lcd.autoscroll() in the void loop() section to create sequences of scrolling text or animations.

This function sets the direction that text is printed to the screen. The default mode is from left to right using the command lcd.leftToRight(), but you may find some cases where it’s useful to output text in the reverse direction:

This code prints the “hello, world!” text as “!dlrow ,olleh”. Unless you specify the placement of the cursor with lcd.setCursor(), the text will print from the (0, 1) position and only the first character of the string will be visible.

This command allows you to create your own custom characters. Each character of a 16×2 LCD has a 5 pixel width and an 8 pixel height. Up to 8 different custom characters can be defined in a single program. To design your own characters, you’ll need to make a binary matrix of your custom character from an LCD character generator or map it yourself. This code creates a degree symbol (°):

The Arduino family of devices is features rich and offers many capabilities. The ability to interface to external devices readily is very enticing, although the Arduino has a limited number of input/output options. Adding an external display would typically require several of the limited I/O pins. Using an I2C interface, only two connections for an LCD character display are possible with stunning professional results. We offer both a 4 x 20 LCD.

The character LCD is ideal for displaying text and numbers and special characters. LCDs incorporate a small add-on circuit (backpack) mounted on the back of the LCD module. The module features a controller chip handling I2C communications and an adjustable potentiometer for changing the intensity of the LED backlight. An I2C LCD advantage is that wiring is straightforward, requiring only two data pins to control the LCD.

A standard LCD requires over ten connections, which can be a problem if your Arduino does not have many GPIO pins available. If you happen to have an LCD without an I2C interface incorporated into the design, these can be easily

The LCD displays each character through a matrix grid of 5×8 pixels. These pixels can display standard text, numbers, or special characters and can also be programmed to display custom characters easily.

Connecting the Arduino UNO to the I2C interface of the LCD requires only four connections. The connections include two for power and two for data. The chart below shows the connections needed.

The I2C LCD interface is compatible across much of the Arduino family. The pin functions remain the same, but the labeling of those pins might be different.

Located on the back of the LCD screen is the I2C interface board, and on the interface is an adjustable potentiometer. This adjustment is made with a small screwdriver. You will adjust the potentiometer until a series of rectangles appear – this will allow you to see your programming results.

The Arduino module and editor do not know how to communicate with the I2C interface on the LCD. The parameter to enable the Arduino to send commands to the LCD are in separately downloaded LiquidCrystal_I2C library.

Several examples and code are included in the Library installation, which can provide some reference and programming examples. You can use these example sketches as a basis for developing your own code for the LCD display module.

The I2c address can be changed by shorting the address solder pads on the I2C module. You will need to know the actual address of the LCD before you can start using it.

Once you have the LCD connected and have determined the I2C address, you can proceed to write code to display on the screen. The code segment below is a complete sketch ready for downloading to your Arduino.

The code assumes the I2C address of the LCD screen is at 0x27 and can be adjusted on the LiquidCrystal_I2C lcd = LiquidCrystal_I2C(0x27,16,2); as required.

This function turns off any characters displayed to the LCD. The text will not be cleared from the LCD memory; rather, it is turned off. The LCD will show the screen again when display() is executed.

Scrolling text if you want to print more than 16 or 20 characters in one line then the scrolling text function is convenient. First, the substring with the maximum of characters per line is printed, moving the start column from right to left on the LCD screen. Then the first character is dropped, and the next character is displayed to the substring. This process repeats until the full string has been displayed on the screen.

The LCD driver backpack has an exciting additional feature allowing you to create custom characters (glyph) for use on the screen. Your custom characters work with both the 16×2 and 20×4 LCD units.

To aid in creating your custom characters, there are a number of useful tools available on Internet. Here is a LCD Custom Character Generator which we have used.

This tutorial shows how to use the I2C LCD (Liquid Crystal Display) with the ESP32 using Arduino IDE. We’ll show you how to wire the display, install the library and try sample code to write text on the LCD: static text, and scroll long messages. You can also use this guide with the ESP8266.

Additionally, it comes with a built-in potentiometer you can use to adjust the contrast between the background and the characters on the LCD. On a “regular” LCD you need to add a potentiometer to the circuit to adjust the contrast.

Before displaying text on the LCD, you need to find the LCD I2C address. With the LCD properly wired to the ESP32, upload the following I2C Scanner sketch.

After uploading the code, open the Serial Monitor at a baud rate of 115200. Press the ESP32 EN button. The I2C address should be displayed in the Serial Monitor.

Displaying static text on the LCD is very simple. All you have to do is select where you want the characters to be displayed on the screen, and then send the message to the display.

The next two lines set the number of columns and rows of your LCD display. If you’re using a display with another size, you should modify those variables.

To display a message on the screen, first you need to set the cursor to where you want your message to be written. The following line sets the cursor to the first column, first row.

Scrolling text on the LCD is specially useful when you want to display messages longer than 16 characters. The library comes with built-in functions that allows you to scroll text. However, many people experience problems with those functions because:

In a 16×2 LCD there are 32 blocks where you can display characters. Each block is made out of 5×8 tiny pixels. You can display custom characters by defining the state of each tiny pixel. For that, you can create a byte variable to hold  the state of each pixel.

In summary, in this tutorial we’ve shown you how to use an I2C LCD display with the ESP32/ESP8266 with Arduino IDE: how to display static text, scrolling text and custom characters. This tutorial also works with the Arduino board, you just need to change the pin assignment to use the Arduino I2C pins.

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In this article, I will show you how to communicate with a DWIN display using the serial port of a computer. I got the privilege to receive two displays from the manufacturer for a review in exchange for content made about them. I accepted their offer because I have been always interested in human-machine interfaces (HMI) and I could see that I can use their displays in many of my upcoming projects as well as I can upgrade some of my older projects using the displays.

If you have any inquiries about the screens or want to get a free sample, you can contact them on social platforms like WhatsApp or Email details are given below.

These displays communicate via serial communication through their TX and RX pins. This makes it simple to connect them to microcontrollers without implementing difficult i2c or SPI libraries. Just two wires and the power supply rails (+5 V and GND), that’s all.

The software is created with DWIN’s own developing environment called DGUS. This software creates the binary files for controlling, configuring and handling the display as well as it can communicate with the display via the serial port. The display handles images, fonts, icons and other visual stuff. All these features are compiled into a binary (BIN) file which is uploaded to the display. The uploading of the resources (at least on the displays I have) can be done via an SD card. Certain files can be uploaded via serial connection as well, but generally, the SD card upload method has to be used.

First of all, you need to get the DGUS tool (DGUS_V7640) and the driver for the serial connector (XR21X141X Driver). You can download both from DWIN’s website.

Let’s look at the welcome screen of the DGUS software. Here you have many options. You can start a new project or open an old project, you can generate fonts, pictures…etc, you can start the serial communication tool and many more. I think the first thing that you should do here is to start a new project. You can create a project as I do in this article and follow my steps so you can see how the files are structured and handled.

Click on New, then enter the screen resolution (I manually entered “480X800” because I could not find it in the drop-down list) and select a folder where you want to store the files for your project.

In this simple demo, I want to show you how we can send some data from the serial port to the display and how we can translate the interaction with the display (e.g. touching it) into a message on the serial port.

To be able to communicate with the display, before doing anything we must understand how the display communicates. As I said, it communicates via serial communication. It uses hexadecimal (HEX) characters to send and receive information. There are two types of operations: reading and writing.

There are two things inside the display that can be manipulated: the description pointers (SP) and the variable pointers (VP). They sound intimidating in the beginning but actually, they are very simple. Both SP and VP are pointing at RAM addresses, each address (for example 0x5000) has two bytes: a high byte and a low byte. The description pointers point at RAM spaces where the properties of a control is stored. These properties are for example the X and Y position of a control element, the colour of it or other properties. So, you can manipulate these things through the serial port by accessing the control through its SP address. The VP addresses point at different variables. For example, you can send a number from the serial port to the display by sending the value to a VP address that is defined for a control. Also, you can read these VP addresses using the serial port and fetch the values. A crucial thing to remember is that you have to carefully select the address of both of these variables. If the addresses are not planned carefully enough, two addresses can overlap and they will cause you trouble.

There will be one field on the display that receives the raw output value of an ADC channel of the Arduino microcontroller. In this demo, I will emulate this by manually sending the number to the display via the serial port. This will be the “receiving part” (Serial→ DWIN) in the example. The sending part (DWIN → Serial) will be a slider that can change a value between 0-1000. The value of the slider will be shown on the display as well as it will be sent to the serial port. I also add a button that will turn an LED on and off.

The first four numbers are the position (X, Y) and the dimension (H, W) variables. Then, you can give a name to the field if necessary. After that, you can define an SP address, but I leave it as default because I will not want to manipulate any of the parameters of the properties. However, I have given a value for the VP address (2000). This will be the address where we need to send the ADC values from the serial or later from a microcontroller. The “Show colour” is just the colour of the font. The word bank ID is the ID number of the font file we use. The rest of the units are more or less self-explanatory.

The slider variable parameters are shown on the right side of this text block. I already explained all the parameters for the ADC variable and they are almost the same here. Since this is a different value, it needs another address. I put the variable on the 1000 VP address. This means that when the slider is moved, it will have to write its position to the 1000 VP address and we also know that if the display sends something to the serial with the 1000 VP address then it comes from this variable that represents the position of the slider.

Once the control is added to the display, we can adjust its settings. Here, I also chose the 1000 VP address. This is very important! Why I did this is because when I move the slider, then the display will put the corresponding value in the 1000 address. Since the slider variable is also tied to this address, it will get this value and it will display it on the display as a human-readable number. Furthermore, you can see that I checked the “Data auto-uploading” checkbox. This means that whenever I interact with the control, the display will send out the value of the variable under the 1000 VP address through its serial connection. So, as I mentioned above, when we see a message from the display coming from the 1000 address, we will know that the value in that message is the position of the slider. The dragging mode does not need any explanation, neither the “start value” nor the “terminated value”. I think that this is a mistranslation, I would call this parameter the final value or max value.

I checked the “Data auto-uploading” checkbox so the serial communication automatically happens when there is some change in the data. Then, I skip the next two boxes because it is not used here. Then the key value is important. We could choose any value but I used the 0001 value. Finally, I set the VP Address to 3000.

When the button is pressed, the display will send out a message through the serial port whose value is "0001” and which is coming from the 3000 VP address. Therefore, we can prepare our code on the microcontroller to listen to the 3000 VP address and see when the value 0001 is being read from the address. Then we can very easily write a code that toggles an LED when the above message is received by the MCU.

Here comes a little trick that I needed to discover myself because I could not find an explanation for it. So, first I could not get any reply from the display on the serial terminal whenever I interacted with it. If I sent a command to the display and read the VP address manually, I could see that the value of my variable changed in a way I wanted to, but I could not get it to show up automatically on the serial terminal. Despite the fact that the “Data auto-uploading” was checked in!

Click on the CFG Edit tab. Then, on the left side, you can see an option called “Touch-sensitive Variable Changes Update”. For some weird reason, this is “Non-auto” by default. Change it to “Auto”. Also, if you are bothered by the beeping sound of the display whenever you touch it, change the “Touch sound” to “Off”. Furthermore, you can play around with the “Power-on Display Direction”. In my case, I left it at “0°” because I use the display in portrait mode in an orientation where the serial connector is at the bottom of the display and the SD card reader is at the top. Otherwise, I would use 90° or 270° depending on how I want to rotate the display in landscape mode. Once you chose the settings you want, click on “New CFG” and save the file named as T5LCFG.CFG in the DWIN_SET folder of your project. Later on, you will have to copy this file onto an SD card, so it is better to keep everything together in the same folder.

But, before doing anything, please DO NOT hot-swap the SD card in the display. First, remove all power (screen is OFF), then plug in the SD card to the slot, and then connect the display to a power source. Otherwise, you might damage the display. Also, you cannot use the display’s SD card slot as a card reader to upload the config files to the display. You will need a separate card reader!

Once all the files are on the SD card under the DWIN_SET folder, put the card into the display while the display is OFF! After the card is inserted, you can connect the display to a power source. If everything is correct, you should see a blue display that is showing you the progress of the uploading from the SD card to the display. It shows you which file is being transferred at the moment and at the end of the process, there will be a message at the top of the screen (2nd line) which says:SD Card Process… END !

Then, I touched the slider area at a random place which resulted in 621 as the output value. The response on the serial terminal was:5A A5 06 83 10 00 01 02 6D

On the software side, you have to download and install a new LiquidCrystal_I2C library for Arduino, which has the capability to talk to the LCD display over the I2C bus. Heres a link to the library. Follow the example code for the DFRobot board, which turns out to have the same configuration as this LCD, and it should fire right up for you. The LCD has white characters on a backlit blue background, and looked great.