the lcd touch screen brightness cannot adjustment free sample

This article was co-authored by wikiHow staff writer, Kyle Smith. Kyle Smith is a wikiHow Technology Writer, learning and sharing information about the latest technology. He has presented his research at multiple engineering conferences and is the writer and editor of hundreds of online electronics repair guides. Kyle received a BS in Industrial Engineering from Cal Poly, San Luis Obispo.

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Select the Networkicon on the right side of the taskbar, and then move the Brightnessslider to adjust the brightness. (If the slider isn"t there, see the Notes section below.)

Some PCs can let Windows automatically adjust screen brightness based on the current lighting conditions. To find out if your PC supports this, select  Settings >System>Display. Select Brightness, look for theChange brightness automatically when lighting changes check box, and then select it to use this feature. This automatic setting helps make sure your screen is readable wherever you go. Even if you use it, you can still move theBrightness slider to fine-tune the brightness level for a built-in display.

You might also see another check box displayed: Help improve battery by optimizing the content shown and brightness. Some Windows PCs can automatically adjust the screen brightness and contrast based on content that’s displayed on your built-in screen. For more info, see Adaptive brightness and contrast in Windows.

You might not see the Brightness slider on desktop PCs that have an external monitor. To change the brightness on an external monitor, use the buttons on it.

If you don"t have a desktop PC and the slider doesn"t appear or work, try updating the display driver. Select Search on the taskbar, type Device Manager, and then select Device Manager from the list of results. In Device Manager, select Display adapters, then select the display adapter. Press and hold (or right-click) the display adapter name, then select Update driver and follow the instructions.

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When you update the Bios version to 1.5.0 on your Dell XPS 15 7590 system, you may not be able to adjust the LCD brightness. Open the Device Manager, you would find that multiple entries under the Monitors(See Figure.1). At that time, you can not increase or decrease the brightness in the following ways:

Try to adjust the brightness from the Display Settings/Windows Mobility Center(See Figure.2). The value can adjust but the display is stuck at a certain brightness, there is no effect if you adjust it to 0 or 100.

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NOTE: This causes your computer to restart as it flashes your BIOS with the Update. Please ensure you have the computer connected to a reliable power source during this.

For the video display developer LCD panels are available in many sizes and resolutions, they are also available with many choices of maximum brightness. The following considers the topic of LCD panel brightness, the choices, the methods for adjusting brightness and some brightness adjustment scenarios.

LCD panels are generally rated as to their maximum brightness level which is expressed in Nits, it is equal to Candela/sqm (cd/m2), and this will be at a particular color temperature as noted in the specification, usually 10,000 K. In terms of a practical understanding, the following is a rough guide:

Outdoor displays range from a low end of 700 nits to typically 1,000 or 1,500nits and up with 2,000~2,500nits and even up to 5,000nits seen with some models. This may include standard LCD panels, custom LCD panels as well as custom cut LCD panels.

Virtually all LCD panels have a LED backlight these days, these are powered by an LED driver board. Brightness control via the driver board will be by one of two methods:

PWM (Pulse Width Modulation): This varies the duty cycle of the backlight “on time” – it is predominant in modern LCD panel LED backlight designs to enable support for digital brightness controls.

Analog: Uses a simple variable voltage to adjust brightness, for example this might be a dial or slider type potentiometer / variable resistor. To see how to enable analog backlight adjustment visit: https://www.digitalview.com/blog/brightness-adjustment/

One of the advantages of LED for the backlight is the range of adjustment that is possible, however it is important to note that the range varies significantly from model to model. Some industrial panels can be turned to very low light levels making them suitable for use in special environments such as at night. Lower cost panels limit the range of brightness to what might be required for typical usage, whereas panels with full range dimming from full off to full on require more complex backlight drivers.

Backlight lifetime: Many LCD panels have a backlight lifetime rating of 50,000 hours (typically measured to half brightness), this can be extended by running the LED backlight at a lower brightness level. Some panels may only offer 30,000 hours as a lower cost solution while other panels may offer up to 100,000 hours for high end applications.

An LCD panel backlight may be constructed so the LED’s are mounted directly behind a light guide diffuser, or they may be mounted along one or more edges of the light guide.

Active backlight: This is a function of some LCD panel backlights to automatically adjust the backlight brightness in response to the image. For more advanced systems there is an LED array making up the LED backlight, this adjusts the brightness in areas localized to the image being shown. This can greatly enhance the brightness across the display and is being used primarily with video, for example on consumer TV sets. It is not useful to all image types, for example a spreadsheet or content like maps or data is not likely to benefit.

Local dimming: Some LCD panels with direct LED may support local dimming so the LED’s are dimmed in response to the image close to them. This will not be at the same resolution as the LCD panel itself but will help greater contrast over the display by enhancing the brightness in bright areas of the image and darkening the image in dark parts of the image.

Both of the above techniques are likely to be more beneficial to certain types of content than others. For example a movie is likely to benefit more than a spreadsheet.

For the LCD monitor manufacturer it is important to consider that any covering over the LCD panel will reduce the brightness. For example the protective glass over a digital signage display, or a touch screen, or a semi-silvered mirror. So if a specific brightness is required the measurement should be taken with these in place.

There are various relatively low cost brightness meters available, typically in the couple of hundred dollars range. It is difficult to comment on the accuracy of these but we have found them to be within 5% of each other, though more importantly they do appear to be quite consistent in measurement so good for measurement comparisons. For more accurate measurement there are light meters from companies such as Minolta that can be calibrated, the cost may run into several thousand dollars.

Examples of light meters costing a few hundred dollars include SpyderX by Datacolor (needs a PC), a handheld meter is the SM208 by Sanpometer (search SM208 meter). Note: Many light meters, including smartphone apps, will be meters used for photography and not give readings in nits (or candelas). LCD panel specifications are typically measured using nits.

PWM and Analog: Most Digital View LCD controllers support PWM and Analog as a method for adjusting the backlight brightness level (this is noted in the column headed “Other” on the controller board summary table: https://www.digitalview.com/controllers/lcd-controllers-home.html. Also see https://www.digitalview.com/blog/brightness-adjustment/ for a guide to using a dial or slider type variable resistor to adjust the backlight.

DPMS (Display Power Management System): The backlight will be automatically turned off after a period if there is no valid video signal being received.

Ambient light sensor: The backlight is adjusted for brightness or powered off depending on ambient light conditions. This uses a light sensor attached to the LCD controller board, see https://www.digitalview.com/blog/light-sensor-app-note/ for more details.

The specifics of the backlight control are documented separately for each LCD controller model (product summary here) in the product manual available for download on the product page.

Note: There are two ways to adjust the perceived brightness of a LCD panel or LCD monitor, the backlight and the black-level. Very often, particularly in the past, the monitor brightness setting adjusted the black-level, this adjusts the LCD but not the backlight.

Color, color temperature etc: In addition to adjusting the brightness other settings may be adjusted as well. For example the color temperature or for example a switch to green monochrome for night vision.

Night-safe lighting (update) : Dual-rail backlights can also be supported. These special backlight enable normal brightness and extreme low level brightness with custom night-safe lighting. Contact us for details.

Note: We have a blog on methods for implementing an ambient light sensor with Digital View LCD controller boards to automatically adjust the backlight or system power, see: Ambient Light Sensor

Update March 2019: Most of the above remains unchanged except for the increased availability of high bright LCD panels of around the 1,000 nit to 2,500 nit range. AUO for example has a number of large size LCD panels with 1,500 nit brightness for the digital signage market. Tianma has panels under 20″ with 1,000 nit to 1,500 nit brightness for various outdoor applications.

The other change is that high bright panels are now increasing edge-lit, this makes the panels thinner and these panels tend to use less power than the previous models. One of the benefits for monitor designers is easier heat management and reduced overall display system costs.

First and most importantly, if at all possible adjust the display backlight, rather than using software correction of pixel values. If you dim the backlight you still get full or near-full dynamic range, giving you a clearer, "deeper" image that tends to be more readable.

Software adjustment can"t make the blacks darker, it just makes white greyer and reduces contrast. So instead of using pixel values from 0-255 it might use from 0-180 for example. Everything looks flatter.

A tool like Redshift can be useful for changing colour balance, but as much as possible you should try to change brightness with backlight adjustment.

Last I checked, most displays unfortunately do(did?) not implement backlight control from software. There"s a standard for it, DDC/CI but adoption has been limited. Try the ddccontrol tool with your monitor and see if you have any luck.

I"ve only seen it in very high end displays intended for calibrated photo and video work ... and even many of those use a USB connection and custom USB HID based driver instead of the DDC/CI standard. I"m pretty outdated though, and the linked article claims that basic options like brightness and contrast are widely supported now.

Some cheap displays don"t support backlight control at all. The brightness controls on the display just adjust the pixel values on the LCD, just like software control does. Do not use these controls if you have such a monitor; it"s usually better to do the correction in software, certainly no worse.

All too many displays do have backlight control, but minimum brightness is still eye-searing. They can sometimes be modified, but otherwise your best bet is setting them to minimum backlight brightness and then living with changing pixel values to get them even dimmer.

It really annoys me that displays have such a limited backlight intensity range, often artifically and arbitrarily limited, starting at eye-searing to "the power of a million suns". I look for dim backlights when I"m speccing out displays to buy.

The details are somewhat driver and software specific, but your laptop should offer convenient Fn keys that make it easy, and the OS should have a simple display brightness slider. The xbacklight utility offers a convenient command line control for this, though on my system it doesn"t seem to like to go below 1% brightness and goes straight to black.

I twiddle the driver controls because my T460 is very bright - wonderful during the day, but horrible at night. The minimum brightness step offered by the fn key adjustments is still way too bright, but the driver provides much finer grained control. xbacklight only lets me get down to brighness 8/255 and I"d like So I tell it to run at 4/255 brightness:

This works on a Lenovo T460 with Intel graphics, but other drivers and hardware may have different entries under /sys/class/backlight with different range limits etc.

When you lower brightness you might want to increase contrast in software a bit, especially if working on text. It"ll cost you image quality, but gain you readability at low brightness. The xgamma utility will let you do that, e.g.

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In my research thus far, the AMOLED screen technology is to blame. When the display circuits get old or damaged, they don"t sustain current at low power settings. In LED screens, a back light controls brightness, but AMOLED screens send current to each pixel for brightness control. If the circuit is damaged, or any corrosion has built up inside, this could attenuate the current below the point required to sustain light flow. I see this problem with some LED and CFL lights on motion sensor switches. Just enough current goes through the motion sensor to keep it"s circuits active, and that current causes a flicker in the light.

With the screen though, since the problem is only resolved when you increase the brightness just a bit above minimum, it seems anything that lowers the display power (auto brightness for example) will cause it to flicker if this setting gets too low. I also noticed that before the screen locks on timer, it dims to low power for a few seconds and flickers as a result. There are apps that attempt to resolve this by putting a translucent black screen over your desktop and apps. This keeps the power up on the pixels but adds a black overlay, kind of like a screen filter. You can adjust the darkness if you need it to save your eyes when reading in the dark but it doesn"t help save power any. They also require a rooted device, which could void warranties. The reason for this I believe is because apps are supposed to operate in a way they don"t intrude on each other, and a filter that lays over your screen does in fact alter the output of your display rendering. With the added security concerns of these apps possibly collecting screen shots and sending them to another site, I would avoid this. Best to use a physical screen overlay you can put on or remove as needed as long as it doesn"t interfere with your touch screen options.

Ultimately, these devices were meant for replacement every 2 to 3 years so if you"re like me and you like to make your investment last, best thing to do is apply any work around you can come up with. A repair shop may be able to wipe the circuit boards down with a solution that clears away corrosion, but it won"t repair any weakened pixels. I"m still using a Samsung S4 and only now that I have verified it won"t upgrade to the Android 6.0 OS am I considering replacing it within the next year or so.

Security notice: The application will be started with root privileges. If you use your pi only for playing around, this should be no problem. Otherwise you should figure out if this is a problem for you.

Screen brightness might be tricky to control. On some machines physical hardware switches are missing and software solutions may not work well. However, it is generally possible to find a functional method for a given hardware. This article aims to summarize all possible ways to adjust the backlight.

There are many ways to control brightness of a monitor, laptop or integrated panel (such as the iMac). According to these discussions and this wiki page the control method can be divided into these categories:

brightness is controlled by either the ACPI, graphic or platform driver. In this case, backlight control is exposed to the user through /sys/class/backlight which can be used by user-space backlight utilities.

Note: Since OLED screens have no backlight, brightness cannot be controlled by changing backlight power on laptops equipped with an OLED screen. In this case, perceived screen brightness can be adjusted with a PWM control (not implemented in the Linux kernel) or via software color correction.

The brightness of the screen backlight is adjusted by setting the power level of the backlight LEDs or cathodes. The power level can often be controlled using the ACPI kernel module for video. An interface to this module is provided via a /sys/class/backlight/.

In this case, the backlight is managed by an ATI graphics card. In the case of an Intel card, the directory is called intel_backlight. In the following examples, acpi_video0 is used. If you use an Intel card, simply replace acpi_video0 with intel_backlight in the examples.

By default, only root can change the brightness by this method. To allow users in the video group to change the brightness, a udev rule such as the following can be used:

Reason: Explain why it is not possible to alter file permissions with GROUP="video", MODE="0664". (Discuss in Talk:Backlight#Udev rules for permissions of brightness doesn"t work)

Sometimes ACPI does not work well due to different motherboard implementations and ACPI quirks. This results in, for instance, inaccurate brightness notifications. This includes some laptops with dual graphics (e.g., Nvidia/Radeon dedicated GPU with Intel/AMD integrated GPU). Additionally, ACPI sometimes needs to register its own acpi_video0 backlight even if one already exists (such as intel_backlight), which can be done by adding one of the following kernel parameters:

Note: The systemd-backlight service restores the previous backlight brightness level at boot. To prevent conflicts for the above rules, see #Save and restore functionality.

Tip: To set the backlight depending on power state, see Power management#Using a script and an udev rule and use your favourite backlight utility in the script.

In some cases (e.g. Intel Mobile 945GME [1]), it is possible to set the register of the graphic card to adjust the backlight. It means you adjust the backlight by manipulating the hardware directly, which can be risky and generally is not a good idea. Not all of the graphic cards support this method.

DDC/CI (Display Data Channel Command Interface) can be used to communicate with external monitors implementing MCCS (Monitor Control Command Set) over I2C. DDC can control brightness, contrast, inputs, etc on supported monitors. Settings available via the OSD (On-Screen Display) panel can usually also be managed via DDC. The kernel module i2c-dev may need to be loaded if the /dev/i2c-* devices do not exist.

Users of NVIDIA"s proprietary drivers may need to add Option "RegistryDwords" "RMUseSwI2c=0x01; RMI2cSpeed=100" to the Device section in /etc/X11/xorg.conf.d/20-nvidia.conf (generated by nvidia-xconfig) or options nvidia NVreg_RegistryDwords=RMUseSwI2c=0x01;RMI2cSpeed=100 to /etc/modprobe/conf.d/nvidia.conf. Confirm that the settings are correctly applied with grep RegistryDwords /proc/driver/nvidia/params and check that the values are not empty. See [2] and [3]

ddcutil will fail to set some VCP features if there is a feature enabled on the monitor which already automatically adjusts them (e.g. Dynamic Contrast Ratio or BenQ"s Eye Care technology).

To facilitate binding screen brightness control to a keyboard shortcut, it may be convenient to enable non-superuser access to the relevant I2C devices. This can be achieved by adding a group i2c and configuring udev to set this group as the owner of the I2C devices. See [4].

Switching off the backlight (for example when one locks a notebook) can be useful to conserve battery energy. Ideally the following command should work for any Xorg graphical session:

If the previous commands do not work, there is a chance that vbetool may work. Note, however, that in this case the backlight must be manually activated again. The command is as follows:

The systemd package includes the service systemd-backlight@.service, which is enabled by default and "static". It saves the backlight brightness level at shutdown and restores it at boot. The service uses the ACPI method described in #ACPI, generating services for each folder found in /sys/class/backlight/. For example, if there is a folder named acpi_video0, it generates a service called systemd-backlight@backlight:acpi_video0.service. When using other methods of setting the backlight at boot, it is recommended to stop systemd-backlight from restoring the backlight by setting the kernel parameters parameter systemd.restore_state=0. See

Note: Some laptops have multiple video cards (e.g. Optimus) and the backlight restoration fails. Try masking an instance of the service (e.g. systemd-backlight@backlight:acpi_video1 for acpi_video1).

Note: The utilities in the following table can be used to control screen brightness. All of them are compatible with Wayland and do not require X. Some (like video (or input) group to modify brightness.

Manages screen temperature (Xorg only) and smoothly dims brightness after a timeout. Supports ambient light sensors [5]. Can turn webcam into an ambient light sensor.

Automatic brightness adjustment based on screen contents and ambient light. Can use webcam or time to simulate ambient light sensor. Supports keyboards and external monitors. Uses wlroots.

Tip: Commands involving these utilities can be bound to the XF86MonBrightnessUp and XF86MonBrightnessDown keyboard keys as described in Keyboard shortcuts#Xorg.

If you get the "No outputs have backlight property" error, it is because xrandr/xbacklight does not choose the right directory in /sys/class/backlight. You can specify the directory by setting the Backlight option of the device section in /etc/X11/xorg.conf.d/20-video.conf. For instance, if the name of the directory is intel_backlight and using the Intel driver, the device section may be configured as follows:

Note: Using this with an iGPU+dGPU setup can cause unpredictable screen update lag and/or flickering in user interface items inside apps that are offloaded to the dGPU. Only use this if all else fails.

If you have enabled Intel Fastboot you might also get the No outputs have backlight property error. In this case, trying the above method may cause Xorg to crash on start up. You should disable it to fix the issue. It is known to cause issues with brightness control.

$ gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.freedesktop.DBus.Properties.Set org.gnome.SettingsDaemon.Power.Screen Brightness ""

$ gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.gnome.SettingsDaemon.Power.Screen.StepUp

$ gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.gnome.SettingsDaemon.Power.Screen.StepDown

Color correction does not change the backlight power, it just modifies the video lookup table: this means that your battery life will be unaffected by the change. Nevertheless, it could be useful when no backlight control is available (desktop PCs or laptops with OLED screens).

Clight — User daemon utility that aims to fully manage your display. It can manage the screen temperature depending on the current time of the day, just like redshift does. It tries to use

Redshift does not support Wayland (without a patch or fork like AUR). But it is possible to apply the desired temperature in tty before starting a compositor. For example:

This should roughly double luma in the image. It will sacrifice color quality for brightness, nevertheless it is particularly suited for situations where the ambient light is very bright (e.g. sunlight).

This can also be used to reduce perceived brightness in a dark room by specifying some value less than 1 (e.g. 0.5), this is useful when no backlight control is available (e.g. desktop PC).

Users of NVIDIA"s proprietary drivers can change display brightness via the nvidia-settings utility under "X Server Color Correction." However, note that this has absolutely nothing to do with backlight (intensity), it merely adjusts the color output. (Reducing brightness this way is a power-inefficient last resort when all other options fail; increasing brightness spoils your color output completely, in a way similar to overexposed photos.)

Reason: Modern LED display using IPS panel usually utilize DC dimming instead of PWM dimming. This can be indicated by the two upper bytes of 0xC8254 register 0x0001, which means the frequency is almost infinity. (Discuss in Talk:Backlight)

Laptops with LED backlight are known to have screen flicker sometimes. This is because the most efficient way of controlling LED backlight brightness is by turning the LED"s on and off very quickly varying the amount of time they are on.

However, the frequency of the switching, so-called PWM (pulse-width modulation) frequency, may not be high enough for the eye to perceive it as a single brightness and instead see flickering. This causes some people to have symptoms such as headaches and eyestrain.

Period of PWM (inverse to frequency) is stored in 2 higher bytes of 0xC8254 register (if you are using the Intel GM45 chipset use address 0x61254 instead). To manipulate registers values install

Embedded Display Port (eDP) v1.2 introduced a new display panel control protocol for backlight and other controls that works through the AUX channel [7]

Note: This behavior and their workarounds have been confirmed on the Dell M6700 with Nvidia K5000m (BIOS version prior to A10) and Clevo P750ZM (Eurocom P5 Pro Extreme) with Nvidia 980m.

On some systems, the brightness hotkeys on your keyboard correctly modify the values of the acpi interface in /sys/class/backlight/acpi_video0/actual_brightness but the brightness of the screen is not changed. Brightness applets from desktop environments may also show changes to no effect.

If you have tested the recommended kernel parameters and only xbacklight works, then you may be facing an incompatibility between your BIOS and kernel driver.

A workaround is to use the inotify kernel api to trigger xbacklight each time the value of /sys/class/backlight/acpi_video0/actual_brightness changes.

Due to a bug introduced recently in the amdgpu driver, the backlight"s actual_brightness value is reported as a 16-bit integer, which is outside the 8-bit range specified in max_brightness. This causes the systemd-backlight service to attempt to restore, at boot time, a value that is too large and ends being truncated to maximum brightness (255).

While the bug is not addressed, one possible workaround is to modify the stored brightness to within the correct range before it is restored. This can be accomplished with a script and a service unit:

On certain systems, the backlight level reported by the driver is in the correct range [0, 255], but systemd still fails to restore the correct value. This is probably due to a race in the kernel. In this case, truncating the brightness level will not help since it is already in the correct range. Instead, saving the brightness level to systemd before shutting down could work as a workaround. This can be accomplished by the following script and service unit:

A calibrated display is not just for photographers. If you browse inspiration photos online, send color samples back and forth via e-mail, or transfer color files between suppliers and customers, you need to calibrate and profile your display to trust the colors you see on-screen.

When talking about monitor calibration, many people interchange illuminance, luminance and brightness, but they are not the same. Here are the differences you need to understand to properly calibrate and profile your display.

Luminanceis the luminous intensity projected on a given area and direction. Luminance typically describes the intensity of emitted light. In the case of our display profiling products, we measure the luminance of the cd/m2 as the unit of measure.

Brightnessis what we perceive when lumens fall on the rods and cones of our retina. When we speak of brightness, we use subjective words like “dim” or “brilliant” because it cannot be measured like luminance, but it can be scaled in percentages.

The best way to understand the difference between luminance and illuminance is to picture a lamp shining on a desk. Luminance describes the amount of light passing through the lightbulb, while illuminance describes the light hitting the desk. Because luminance and illuminance are quantifiable, they are not interchangeable with brightness. Luminance is the measurable quality of light that most closely corresponds to brightness, which we cannot objectively measure. We can only perceive it.

For displays, luminance helps determine how much the light is affecting on-screen color. During profiling, you can set different monitors to the same luminous intensity by choosing the same luminance in cd/m2. Most LCD users find that setting luminance at 120 is bright enough to judge color and detail in highlights and shadows, but if you’re having a hard time seeing details try selecting a lower value. Some calibration programs offer an option to have the software automatically adjust your display’s luminance to match the ambient room light.

Many displays automatically adjust brightness and contrast based on the ambient light. You can also use the monitor’s manual controls to brighten or dim the screen based on your personal preference. Lowering the brightness value will result in a darker image, while raising the brightness will make it lighter.

i1Profiler is our preferred solution for monitor calibration and profiling. It is wizard-based and walks you through every step in the profiling process using either Basic or Advanced mode.Learn how it works in

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.

In this simple sketch we show you the most useful and important functions from the LiquidCrystal_I2C library. So, let’s take a quick look at how the code works.

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.

Then, you need to set the display address, the number of columns and number of rows. You should use the display address you’ve found in the previous step.

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:

After reading the previous section, you should be familiar on how this sketch works, so we’ll just take a look at the newly created function: scrollText()

The messageToScroll variable is displayed in the second row (1 corresponds to the second row), with a delay time of 250 ms (the GIF image is speed up 1.5x).

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.

Then, in the setup(), create a custom character using the createChar() function. This function accepts as arguments a location to allocate the char and the char variable as follows:

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.