lcd screen not displaying free sample

Liquid crystal displays (LCDs) are the most widely used display technology. Their applications cover TV, mobile phone, appliances, automotive, smart home, industrial meters, consumer electronics, POS, marine, aerospace, military etc. LCD screen display problem can occur for several reasons.

Effect of environmental conditions on the LCD assembly. Environmental conditions include both the effects of temperature and humidity, and cyclic loading.

Effect of manufacturing process. With the development of LCD for more than 40 years and the modern manufacturing equipment, this kind if defects are getting rear.

Common failures seen in LCDs are a decrease in screen contrast, non-functioning pixels or the whole display, and broken glass. Different kinds of LCD display problem need to have different kinds of fix methods or make the decision not worthwhile to repair.

Broken glassIf you accidently drop the LCD and you find it broken on the surface but the display still works. You might just break the touch panel; you can find a repair house or find a youtube video to replace the touch panel. If you find the display not showing, especially you find the fluid leaking out. You need to reply the whole display modules.

Dim LCD displayLCD can’t emit light itself. It uses backlight. Normally, the backlight is not fully driven, you can increase the LED backlight to make a dim LCD display brighter. But if you LCD display has been used for a long time, it is possible that the LED backlight has to be the end of life (not brightness enough) if you turn on 100% backlight brightness. In that case to fix LCD screen, you have to find a way to change the backlight. For some display, it is an easy job but it can be difficult for other displays depending on the manufacturing process.

Image sticking (Ghosting)Sometimes, you will find the previous image still appearing at the background even if you change to another image. It is also called burn in. This kind of failure doesn’t need to repair by professionals. You can simply shut off the display overnight, this kind of problem will go away. Please do remember that displaying a static image for a long time should be avoided.

LCD has white screen – If a LCD has a white screen which means the backlight is good. Simply check your signal input sources which are the most causes. It can also be caused by the display totally damaged by ESD or excess heat, shock which make the LCD controller broken or the connection failure which has to be repaired by professionals.

Blur ImagesAs the LCD images are made of RGB pixels, the screen shouldn’t be blur like old CRT displays. If you do see blur images, they might be caused by two reasons. 1) LCD has certain response time, if you are playing games or watch fast action movies, some old LCD displays can have image delays. 2) The surface of the LCD is made of a layer of plastic film with maximum hardness of 3H. If you clean the surface often or use the wrong detergent or solvent which cause the surface damage. To fix damage on LED screen it’s need to be changed with professionals.

The LCD screen is vital for operating the printer. Should you encounter any kind of trouble, such as a dead screen, corrupted text, or other issues, please refer to the guide below.

First of all, unscrew the LCD screen from the printer frame, remove both M3x10 screw holding it the LCD board in the plastic casing, and remove it from the casing. See if the problem still appears when the LCD is not pressed by the casing.

Firmware updates are necessary to keep your printer up to date. However, the installation of incorrect firmware can lead to letter corruption on the LCD screen. There"s an easy fix, though:

There is a small chance the printer"s LCD screen can glitch out by electrostatic discharge when inserting the SD card. Try to turn the printer off and on again.

This problem usually appears only on user-assembled printers. If your printer"s LCD screen remains blank or displays corrupted symbols after you turn on the printer, there is a chance it is caused by incorrect wiring. Follow these steps to fix the issue.

Double-check that all cables are properly seated and they are not visibly damaged. Depending on the model of your printer, please refer to the following guides for information on how to make sure the cables are properly connected: Einsy RAMBo electronics wiring (MK3/MK3S/MK3S+) and Mini RAMBo electronics wiring (MK2S, MK2.5, MK2.5S).

If you suspect that the LCD ribbon cables connectors are not firmly seated in the slots, disconnect the LCD ribbon cables and check the slots for any bent pins. If there are bent pins, you can use tweezers to fix them. However, be very careful not to break the pin(s) completely.

Many Apple products use liquid crystal displays (LCD). LCD technology uses rows and columns of addressable points (pixels) that render text and images on the screen. Each pixel has three separate subpixels—red, green and blue—that allow an image to render in full color. Each subpixel has a corresponding transistor responsible for turning that subpixel on and off.

Depending on the display size, there can be thousands or millions of subpixels on the LCD panel. For example, the LCD panel used in the iMac (Retina 5K, 27-inch, 2019) has a display resolution of 5120 x 2880, which means there are over 14.7 million pixels. Each pixel is made up of a red, a green, and a blue subpixel, resulting in over 44 million individual picture elements on the 27-inch display. Occasionally, a transistor may not work perfectly, which results in the affected subpixel remaining off (dark) or on (bright). With the millions of subpixels on a display, it is possible to have a low number of such transistors on an LCD. In some cases a small piece of dust or other foreign material may appear to be a pixel anomaly. Apple strives to use the highest quality LCD panels in its products, however pixel anomalies can occur in a small percentage of panels.

In many cases pixel anomalies are caused by a piece of foreign material that is trapped somewhere in the display or on the front surface of the glass panel. Foreign material is typically irregular in shape and is usually most noticeable when viewed against a white background. Foreign material that is on the front surface of the glass panel can be easily removed using a lint free cloth. Foreign material that is trapped within the screen must be removed by an Apple Authorized Service Provider or Apple Retail Store.

In this Arduino tutorial we will learn how to connect and use an LCD (Liquid Crystal Display)with Arduino. LCD displays like these are very popular and broadly used in many electronics projects because they are great for displaying simple information, like sensors data, while being very affordable.

You can watch the following video or read the written tutorial below. It includes everything you need to know about using an LCD character display with Arduino, such as, LCD pinout, wiring diagram and several example codes.

An LCD character display is a unique type of display that can only output individual ASCII characters with fixed size. Using these individual characters then we can form a text.

If we take a closer look at the display we can notice that there are small rectangular areas composed of 5×8 pixels grid. Each pixel can light up individually, and so we can generate characters within each grid.

The number of the rectangular areas define the size of the LCD. The most popular LCD is the 16×2 LCD, which has two rows with 16 rectangular areas or characters. Of course, there are other sizes like 16×1, 16×4, 20×4 and so on, but they all work on the same principle. Also, these LCDs can have different background and text color.

Next, The RSpin or register select pin is used for selecting whether we will send commands or data to the LCD. For example if the RS pin is set on low state or zero volts, then we are sending commands to the LCD like: set the cursor to a specific location, clear the display, turn off the display and so on. And when RS pin is set on High state or 5 volts we are sending data or characters to the LCD.

Next comes the R/W pin which selects the mode whether we will read or write to the LCD. Here the write mode is obvious and it is used for writing or sending commands and data to the LCD. The read mode is used by the LCD itself when executing the program which we don’t have a need to discuss about it in this tutorial.

After all we don’t have to worry much about how the LCD works, as the Liquid Crystal Library takes care for almost everything. From the Arduino’s official website you can find and see the functions of the library which enable easy use of the LCD. We can use the Library in 4 or 8 bit mode. In this tutorial we will use it in 4 bit mode, or we will just use 4 of the 8 data pins.

We will use just 6 digital input pins from the Arduino Board. The LCD’s registers from D4 to D7 will be connected to Arduino’s digital pins from 4 to 7. The Enable pin will be connected to pin number 2 and the RS pin will be connected to pin number 1. The R/W pin will be connected to Ground and theVo pin will be connected to the potentiometer middle pin.

We can adjust the contrast of the LCD by adjusting the voltage input at the Vo pin. We are using a potentiometer because in that way we can easily fine tune the contrast, by adjusting input voltage from 0 to 5V.

Yes, in case we don’t have a potentiometer, we can still adjust the LCD contrast by using a voltage divider made out of two resistors. Using the voltage divider we need to set the voltage value between 0 and 5V in order to get a good contrast on the display. I found that voltage of around 1V worked worked great for my LCD. I used 1K and 220 ohm resistor to get a good contrast.

There’s also another way of adjusting the LCD contrast, and that’s by supplying a PWM signal from the Arduino to the Vo pin of the LCD. We can connect the Vo pin to any Arduino PWM capable pin, and in the setup section, we can use the following line of code:

It will generate PWM signal at pin D11, with value of 100 out of 255, which translated into voltage from 0 to 5V, it will be around 2V input at the Vo LCD pin.

First thing we need to do is it insert the Liquid Crystal Library. We can do that like this: Sketch > Include Library > Liquid Crystal. Then we have to create an LC object. The parameters of this object should be the numbers of the Digital Input pins of the Arduino Board respectively to the LCD’s pins as follow: (RS, Enable, D4, D5, D6, D7). In the setup we have to initialize the interface to the LCD and specify the dimensions of the display using the begin()function.

The cursor() function is used for displaying underscore cursor and the noCursor() function for turning off. Using the clear() function we can clear the LCD screen.

So, we have covered pretty much everything we need to know about using an LCD with Arduino. These LCD Character displays are really handy for displaying information for many electronics project. In the examples above I used 16×2 LCD, but the same working principle applies for any other size of these character displays.

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 (°):

If you found this article useful, subscribe via email to get notified when we publish of new posts! And as always, if you are having trouble with anything, just leave a comment and I’ll try to help you out.

TFT LCD image retention we also call it "Burn-in". In CRT displays, this caused the phosphorus to be worn and the patterns to be burnt in to the display. But the term "burn in" is a bit misleading in LCD screen. There is no actual burning or heat involved. When you meet TFT LCD burn in problem, how do you solve it?

Burn in is a noticeable discoloration of ghosting of a previous image on a display. It is caused by the continuons drive of certain pixels more than other pixels. Do you know how does burn in happen?

When driving the TFT LCD display pixels Continously, the slightly unbalanced AC will attract free ions to the pixels internal surface. Those ions act like an addition DC with the AC driving voltage.

Those burn-in fixers, screen fixer software may help. Once the Image Retention happened on a TFT, it may easy to appear again. So we need to take preventive actions to avoid burn in reappearing.

For normal white TFT LCD, white area presenting minimal drive, black area presenting maximum drive. Free ions inside the TFT may are attracted towards the black area (maximum drive area)

When the display content changed to full screen of 128(50%) gray color, all the area are driving at the same level. Those ions are free again after a short time;

4. When the screen is blank but power LED light is on, this is a sign the firmware has been corrupted. This can happen if power or network connection is interrupted before the end of the firmware update. The firmware can be recovered provided the printer is connected to a computer via printer USB cable and the computer shows the printer is connected.

Have you ever left your TV or monitor on for days, stuck on the same image? You return to your screen, only to find an image burned into the display. No matter what you do, it won"t go away. It is a permanent image burn.

Why do monitors and TVs get image burn? Why can"t manufacturers prevent LCDs and plasma screens from a burnt image imprint? Moreover, what can you do to fix an image burn?

Before flat-screens and crystal displays, most TVs and monitors featured CRT (Cathode Ray Tube) technology. In CRTs, individual pixels comprise a red, blue, and green phosphor component. Depending on the intensity of each phosphor component, the pixel appears to the human eye as a unique color.

When a particular still image remains for too long, the intensity of each phosphor component diminishes at an uneven rate. The result is a ghost image on the screen, which is known as image burning.

Plasma displays use plasma, a gaseous substance containing free-flowing ions. When the plasma is not in use, the particles in the plasma are uncharged and display nothing. With the introduction of an electric current, the ions become charged and begin colliding, releasing photons of light.

This is a very simplified version of how a plasma screen works. However, the main thing to understand is that plasma screens use phosphor material (like CRTs) to turn those photons into images.

LCD and LED do not work in the same way as CRTs, either. LCD and LED screens use backlit liquid crystals to display colors. Although manufacturers market screens using LED and LCD, an LED screen is still a type of LCD. The white backlight filters through the liquid crystals, which extract particular colors per pixel.

LCD and LED displays don"t suffer from the same type of image burn as CRTs and plasma screens. They"re not completely clear, though. LCD and LED screens suffer from image persistence. Read on to find out more about image persistence.

Before you can fix screen burn-in, take a second to understand why these images burn in the first place. LCDs and LEDs don"t suffer from burn-in as seriously as plasma screens. But static images can leave an imprint on both display types if left alone for too long. So, why does image burn happen?

First, let"s tackle plasma screen burn-in. Remember why CRTs experience image burn? When a still image remains on the screen for too long, the phosphor components in each pixel wear out at different rates. The uneven burn rates leave behind a ghost image, forever etched into the screen.

Plasma screens also suffer from phosphor deterioration. Plasma burning occurs when pixels on the screen are damaged through long exposure. The phosphor loses its intensity and only shows the light it was fed repeatedly. In this case, the still image, which causes the burn.

LCD and LED screens can also experience image burn, though the image burn process can take longer to develop into a permanent issue. In addition, LCD and LED screens suffer from another issue, known as image retention (also known as image persistence or an LCD shadow).

Image retention is a temporary issue that you are more likely to notice before it becomes a permanent issue. However, proper image burn can still affect LCD, LED, and OLED screens.

Image retention is a different issue from image burn (although it is a precursor to image burn). For example, you"re using an image of a steam train as a reference point for a drawing. You have the steam train image on your screen for a few hours before you decide to play a video game instead.

When you load up the video game on the screen, you can still see the faint outline of the steam train on the screen. The steam train image will remain for a short while, but the movement and color changes of the video game (or film, TV show, or other media type) should erase the retained image.

The other thing to consider is that LED and OLED image burn-in, when it happens, is irreversible. That"s because of how LED and OLED screens work. Individual pixels within an LED display decay when they emit light.

Under normal use, an LED, OLED, or QLED screen won"t suffer image burn. However, if you leave your screen on a single channel for hours every day, then burn-in can become an issue, as it would with almost any screen.

Issues arise when a screen shows a single news channel 24 hours a day, every day, causing channel logos to burn-in, along with the outline of the scrolling news ticker and so on. News channels are a well-known source of television burn-in, no matter the screen type.

Image burn-in fixes exist for LCD and plasma screens. How effective an image burn-in fix is depends on the screen damage. Depending on the length and severity of the image burn, some displays may have permanent damage.

The best fix for screen burn is to prevent it in the first place. Okay, that isn"t super useful if your screen is already experiencing image burn. However, you should always try not to leave your screen on a still image for too long. The time it takes for an image to burn-in varies from screen to screen, between manufacturers, sizes, and panel type.

Another prevention method is to reduce screen contrast as much as you can. Unfortunately, most screens aren"t calibrated correctly, often pushing the contrast and brightness settings too high.

Lower contrast means the lighting across your screen is more even. This means less strain on specific areas of the screen, which helps protect against image burning.

If your plasma or LCD screen already has image burn-in, you can try turning on white static for 12 to 24 hours. The constant moving of white-and-black across your screen in random patterns can help remove the ghost image from your screen.

Unfortunately, this won"t work for extreme cases. Some TVs will have a built-in pattern swiping option that basically accomplishes the same thing (filling your screen with random patterns).

Pixel-shift constantly slightly adjusts the image on your screen, which varies the pixel usage to counteract image burn. You might have to enable a pixel or screen shift option in your screen settings. Pixel-shift is a handy feature for LED and OLED screens that cannot recover from image burn and should help counteract an LCD shadow.

Other modern screens feature built-in screen refresh functions that the manufacturer will advise using to remove image retention and image burn issues.

The best tool for fixing ghost images is JScreenFix. The original program helps fix monitors with dead pixels, but the same company also released an "advanced" version of the tool, known as JScreenFix Deluxe.

While the Deluxe version uses advanced algorithms to repair burned screens and prolong plasma and LCD longevity, the official site is no longer up and running, and there is no way to download the full version officially.

You can find the free version of the Deluxe app online, but it is limited to 20 minutes running at a time. Furthermore, we"re not going to link out to the versions you can find online as we cannot verify the security of these installations. If you do use the Deluxe version, you do so at your own risk.

Another option is to set a completely white desktop background and leaving to run for a few hours. The solid color might reset the image burn. A solid color background is more likely to help with image persistence than image burn, but it is still worth trying.

If you have television burn-in, you can attach a laptop to your TV using an HDMI cable, extend your desktop to the television, and share the white screensaver. Hopefully, that will shift your television burn-in.

The team over at ScreenBurnFixer offers a few different ways you can attempt to fix screen burn on your TV or monitor. As with any other screen burn-in fixes, their chance of working depends on the scale of the issue.

You can head to the ScreenBurnFixer Video page and find a video that matches your screen type, then let the video play for as long as possible (we"re talking multiple hours, not a quick half an hour blast). Alternatively, head to the Chart page and find your device or a device that matches your specifications.

There are several ways you can attempt to fix screen burn-in. The results will vary between the screen type and the level of burn-in. A screen with extensive image burn may not clear entirely, although you might see an improvement.

Some screen degradation over time is understandable. However, if you follow the steps in this guide, you"ll protect your screen from image burn before it becomes a permanent issue.

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.

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.

Funny notice: when you manually enter the resolution, the “X” should be capitalised. If you enter “x”, the software will throw an unhandled exception.

First, the file name has to start with two zeroes, for example, you can name the file as “00_background.jpg”. Then, this file has to be loaded into the DWIN ICL Generator and an ICL file has to be generated from it. Here comes another trick: the ICL file that you just generated has to start with the number “32”, for example, call it “32.ICL”.

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.

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.

Once again, the most important thing here is to give a proper VP address to this field. Always keep track of each control’s VP address and be careful not to define them in the way that they overlap with each other.

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.

Finally, we add the button area over the “LED” text with the orange/brown background. First, let’s select the Touch Control menu and select the “Return Key Code” icon. Probably this is not the most efficient way of doing this, but I found it very simple and I can also easily customize the message to be sent.

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.

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!

It turned out that despite the fact that I enabled the “Data auto-uploading” in the editor, it was not enabled globally in the config file of the display. To enable it, go to settings and click on the DGUS icon.

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!

Please notice that there is a space after the letter “q” and the “j” is the letter of your drive. In my case, I am using a card reader to read the SD card and my computer automatically assigned the letter “j” to my card. Always double-check the letter of your SD card, otherwise, you can format something else!

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 !

From this point, you can upload modified code to the display via USB, but only the files starting with 13, 14 and 22 numbers. I could not find a way to update everything on the display via USB, so if you want to make a change, it is better to stick to the SD card uploading method. The USB connection is used for communicating with the display but not programming it!

Notice that I had to send the above values as 0x5A 0xA5 0x5 0x82…etc, but that is just because of how RealTerm processes the values. Also notice that I have received data (5A A5 03 82 4F 4B) from the display after sending the command. This is just some sort of "acknowledging” message from the display.

987 decimal is 0x03 0xDB in HEX. Please notice that the text shown in the terminal is the acknowledging message. The value sent to the display is in the center text box.

Once you have found the correct part number, see HP Consumer Notebook PCs - Ordering HP certified replacement parts. Use the instructions in this document to order a replacement part.

HP recommends that you only order parts from an authorized HP repair parts dealer. Parts ordered from third-party companies might not perform as expected and might cause additional

This reference describes how to use display templates in the skill service code to achieve the look and feel that you want for your skill. Remember that many users will be using Alexa-enabled devices without screen support, so your skill should always be designed in a voice-first manner.

To include screen displays in their skill, a skill developer must use display templates in the skill service code. These templates are constructed so as to provide a great deal of flexibility for the skill developer.

For context, a response body that includes a Display and Hint directive is shown below. Other directives can also be included. A Hint directive requires that a display template also be included. Only BodyTemplate2, BodyTemplate6, and ListTemplate2 templates support the Hint directive. Note that BodyTemplate1, BodyTemplate3, BodyTemplate7, and ListTemplate1 do not support the Hint directive.

When including the image, it is recommended that you provide several different URL sizes. The image size selected will be the smallest possible size that matches the desired aspect ratio and gives a clear image for the size of the screen where the image is being rendered. See the display sizes in the following table. If you do not provide an image of the appropriate size, the next larger image size will be scaled down for use to fit the intended slot.

As shown in this table, the cumulative file size of all images in a skill response should not exceed 3 MB. In general, keeping image sizes small reduces latency and provides a better customer experience.

While the ASK runtime code will manage your skill execution so that you do not need to develop uniquely for a device, it is helpful to understand how your images will look on different-sized screens. The following table lists image sizes supported by each template on Echo Show and Fire TV Cube. Echo Spot images are scaled down as appropriate. With the backgroundImage field, the display size is the same as for the screen pixel dimensions for full-size images. Do not use smaller images which need to be scaled up, as they will have a poor appearance on a larger device.

The contentDescription property is text used to describe the image for a screen reader. The fields size, widthPixels, and heightPixels are optional. By default, size takes the value X_SMALL. If the other size values are included, then the order of precedence for displaying images begins with X_LARGE and proceeds downward, which means that larger images will be downscaled for display on smaller screens. For the best user experience, include the appropriately sized image, and do not include larger images.

Echo Show and Fire TV Cube support back buttons on all templates, although the developer can choose to hide the back button. On Echo Spot, the back button does not appear at all, but the customer can achieve the same effect with a long swipe from the left edge of the screen, if the backButton object is set to "VISIBLE" as described in this section.

The backButton object can have the attribute "HIDDEN" or "VISIBLE". If not included in a template response, then by default the back button will be shown on the screen.

Note: If the customer selects the back button manually, no event is sent back, so the skill service cannot know if the customer has selected the back button. If the customer states "go back" vocally, an event is sent back with the AMAZON.PreviousIntent, and the skill service is aware.

To use a hint directive in a response, you must also include a display template–other than BodyTemplate1, BodyTemplate3, BodyTemplate7 and ListTemplate1–each of which does not support hints, in your response.

Hints should be used for optional content and to delight customers, and not for important information. If the Hint directive is used in a response, the hint is visible on Echo Show and Fire TV Cube, but not visible on Echo Spot. Thus, every skill that uses hints should be designed so that the hints are optional. A hint can be included on each template, by use of the Hint directive, except for BodyTemplate3 and ListTemplate1.

The Hint directive allows a string value that informs the user what to ask Alexa. When displayed on screen, the hint text appears in the following set form:

Each Alexa-enabled device with a screen allows limited text on the screen, depending on the template used, and the font size used. If the included text exceeds these limits, the text is truncated on the screen display. The user cannot scroll to see the remaining text. Ensure that the text you use in the templates does not exceed these limits.

Markup is not included in the maximum character limits. These character limits are based on a font size of 32px, and must be adjusted proportionately if another font size is used. The default font size is 32px.

Font sizes for Alexa-enabled devices with a screen will scale automatically based on the updated font ramp below. Each template has a default font size set for the primary content to maximize legibility. Those default sizes can be overridden using the values below.

Size 3 is the default. Although Fire TV Cube has a larger screen than the other devices listed, Fire TV Cube also has a higher display size per pixel, so the Fire TV Cube font size values are less than for Echo Show.

Note: For a card, the escaped characters will appear with the markup, which is not desirable. Thus, to properly support both cards and templates, you should encode each separately, and not rely on default display behavior. See: Providing Home Cards for the Amazon Alexa App

The template BodyTemplate3 is a simple body template consisting of fields that you can specify: text, title, token, and image. In this example, the optional backButton, and backgroundImage are not included. The skill icon always appears on the screen at the top right when a display template is rendered onscreen. The skill icon is specified separately when you prepare the skill for launch in the Launch > Store Preview section of the developer console.

the top of the screen), a backgroundImage, and a listItems field. Each list item contains optional token, textContent, and image fields. To create this display:

Each item in a list can be made selectable by touch. For each selectable element on the screen, the skill developer provides an associated token that they will receive in the callback response when the element is selected. See the list templates in the Display Template Reference. The developer may name the tokens using their preferred methodology.

Design this intent so that if a list template is used, items shown on screen can be selected by the user saying the item name, or by saying the number of the item. The skill developer determines in the service (AWS Lambda or web service) whether a user can select by name or by ordinal.

For example, with a recipe skill, the user may navigate from a search screen to selecting a recipe to viewing the ingredients to preparing the recipe, each requiring a separate screen display.

The current screen display with a specified template remains on screen for a skill if the session is not ended, and no new template has been sent. If a response with a card is sent, the screen display with a template will remain in place. Thus, a skill could progress through multiple turns with the same screen in place, unless the display is purposefully changed with a skill response that includes a different template.

For Alexa-enabled devices with screens, the response is parsed for display options. If there are multiple display options, the order of precedence for display is as follows:

Display.RenderTemplate directive. The last-rendered template remains on the screen until another template is sent, or until the skill exits. Thus, the same template will remain on screen for multiple turns unless another template is explicitly sent.

Card. If no template has been sent to the screen, but a card has been sent, this card is displayed on the screen. Cards are rendered on Alexa-enabled devices with a screen using BodyTemplate1.

The default template (BodyTemplate1) is automatically created and displayed if there is no template or card specified in the skill response, and none is currently displayed on screen.

The simple response shown below supports only a card and speech response, and is what a developer would provide if not specifically supporting screen display. Note that if viewed on an Alexa-enabled device with a screen, this card will be rendered using BodyTemplate1.

The following response supports the same card and speech response, but also supports screen display via the use of a display template. In this example, BodyTemplate1 is used as the display template. In this example, the text on screen includes a phrase with bolded emphasis.

When shouldEndSession is not specified or has a value of null, and a Display.RenderTemplate or Alexa.Presentation.APL.RenderDocument or Alexa.Presentation.APL.ExecuteCommands directive is active, the session is kept open, and the screen device does not expect a voice response. If the user says the wake word and a command, this utterance is recognized in the context of the skill.

If there is a reprompt, then the timeout for reprompt is a few seconds with the microphone open and a blue ring displayed, plus a few more seconds for the customer to respond. If Alexa does not hear a response, then a reprompt is rendered, and the customer is given another few seconds to respond. If there is still no response, and shouldEndSession is set to false, the session remains open until the display times out.

On the Test page in the developer console, you can use the Alexa Simulator to test what templates look like when rendered on Echo Show or Echo Spot, even if you do not have a screen device. Fire TV Cube is not supported for skill simulation.

As noted in the Display Template Reference, different devices render the same templates in different ways. For example, with some templates, foreground images in Fire TV Cube and Echo Show become background images in Echo Spot. Thus, for a good customer experience, ensure that you test as thoroughly as possible.

We come across Liquid Crystal Display (LCD) displays everywhere around us. Computers, calculators, television sets, mobile phones, and digital watches use some kind of display to display the time.

An LCD screen is an electronic display module that uses liquid crystal to produce a visible image. The 16×2 LCD display is a very basic module commonly used in DIYs and circuits. The 16×2 translates a display of 16 characters per line in 2 such lines. In this LCD, each character is displayed in a 5×7 pixel matrix.

Contrast adjustment; the best way is to use a variable resistor such as a potentiometer. The output of the potentiometer is connected to this pin. Rotate the potentiometer knob forward and backward to adjust the LCD contrast.

A 16X2 LCD has two registers, namely, command and data. The register select is used to switch from one register to other. RS=0 for the command register, whereas RS=1 for the data register.

Command Register: The command register stores the command instructions given to the LCD. A command is an instruction given to an LCD to do a predefined task. Examples like:

Data Register: The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD. When we send data to LCD, it goes to the data register and is processed there. When RS=1, the data register is selected.

Generating custom characters on LCD is not very hard. It requires knowledge about the custom-generated random access memory (CG-RAM) of the LCD and the LCD chip controller. Most LCDs contain a Hitachi HD4478 controller.

CG-RAM address starts from 0x40 (Hexadecimal) or 64 in decimal. We can generate custom characters at these addresses. Once we generate our characters at these addresses, we can print them by just sending commands to the LCD. Character addresses and printing commands are below.

LCD modules are very important in many Arduino-based embedded system designs to improve the user interface of the system. Interfacing with Arduino gives the programmer more freedom to customize the code easily. Any cost-effective Arduino board, a 16X2 character LCD display, jumper wires, and a breadboard are sufficient enough to build the circuit. The interfacing of Arduino to LCD display is below.

The combination of an LCD and Arduino yields several projects, the most simple one being LCD to display the LED brightness. All we need for this circuit is an LCD, Arduino, breadboard, a resistor, potentiometer, LED, and some jumper cables. The circuit connections are below.