tft lcd monitor blinking free sample
I purchased a 3.2" tft lcd shield + touch panel TF Reader for arduino that claims that it works with the Arduino UNO (even shows it being attached to an Arduino Uno in the product image). I have no idea what the name of the shield is since it doens"t mention it on the shield or in the description for the item but it does say that it uses SSD1289 controller and links to that same website (but a different code [other than UTFT]?? check out the "downloads" on that ebay listing).
I"ve attached it to my Arduino UNO and am using code and libraries from the link below (standard UTFT). The display resolution on the LCD monitor is 320240 pixels so naturally I tried the __UTFT example meant for 320240.__ I"ve modified the code for my display (as far as I know) but all I get is a white, randomly flickering screen (doesn"t always flicker). In the code, I inserted SSD1289 for the controller (search for "DotScott" on this page to see my notes in the code).
Compared to older displays, LCD monitors are an excellent low-cost, low-power solution to our need for a computer display. Unfortunately, some monitor settings can make an LCD screen appear to flicker.
A flickering LCD monitor is more than just an annoyance. It can cause eye strain, headaches, and a host of other ailments, especially if you spend a great deal of time in front of your computer. Luckily, there are some steps you can take to stop the flickering and avoid these problems. In this article, I’ll show you how to stop your LCD monitor from flickering.
Although your computer monitor may appear to be a still image when no one is using it, it is actually being updated constantly. Much like a film strip is just a bunch of static images displayed quickly, your monitor updates at a fast rate to make it look like things are moving smoothly on the screen.
The rate at which your monitor updates is measured in Hertz. One Hertz is equal to one cycle per second. If your monitor is set to update at a rate of 100 Hertz, then it is refreshing 100 times per second. The Hertz used to measure monitor refresh rates is similar to the Gigahertz used to measure the speed of your CPU, except that Gigahertz is a measure expressed in billions of cycles per second.
If the refresh rate on your LCD monitor is set too low, it can appear to be flickering since there aren’t enough updates per second. While some people are comfortable with around 30 Hertz, others can see the flickering and require a higher refresh rate. The most common refresh rate is 60 Hertz.
The refresh rates that you can set for your LCD monitor are largely determined by the capabilities of your monitor. While some LCD monitors can take advantage of several different refresh rates, others are confined to just one or two.
To choose a new refresh rate for your LCD monitor in Windows, begin by clicking on Start > Control Panel > Appearance and Personalization > Display. If you are on Windows 8 or 10, just right-click on the Start button and choose Control Panel. If you’re in icon view, you can click directly on Display.
Click on the Monitor tab and you will notice a few things. First, notice the setting labeledScreen Refresh Rate. This is the current refresh rate for your LCD monitor. Click the drop down menu and Windows will display all of the refresh rates possible for your monitor.
It is likely that your monitor can only use one or two refresh rates, so this list may not be long. Some manufacturers build monitors that can display anywhere from 30 Hertz to 200 Hertz. Normally, monitors with higher refresh rates will be more expensive. A common refresh rate for gaming monitors is 144 Hertz. If the price of a monitor seems too cheap to you, it’s probably because it has a low refresh rate. For example, some new 4K monitors are cheap, but are only 30 Hertz, which can make everything look choppy on the screen.
Also, a lot of monitors will show 59Hz and 60Hz and you can pick between the two. So what’s the difference? It’s basically something to do with rounding and it really doesn’t matter. You can read the exact details on 59Hz vs 60Hz here.
First, make sure you are using the latest driver for your LCD monitor. If the driver is outdated or Windows is using a generic driver, the number of refresh rates available may be limited. Visit the manufacturer website and download the latest driver for your version of Windows.
If that doesn’t work, you can force Windows to use a refresh rate that is not technically supported by the monitor. Be careful, though, because it is possible to damage your monitor hardware if you do this.
On the Monitor tab shown above, there is an option that is checked by default called Hide Modes That This Monitor Cannot Display. By unchecking this option, you can force Windows to use any refresh rate for your monitor that you want.
Notice that right underneath this option, Windows warns you about an unusable or damaged display. Uncheck this option and set your monitor to an unsupported refresh rate at your own risk. Depending on your version of Windows, this option may be grayed out, meaning you can only pick from the refresh rates listed in the box.
Cable – If you can, change the cable connecting your monitor to your computer. In some cases, a defective cable can cause the signal to break while being transmitted across the wire.
Input Port – Another solution is to use a different port on the monitor, if possible. For example, if you are connecting using HDMI, try DVI or DisplayPort or VGA instead and see if that fixes the problem.
Monitor – Lastly, the monitor itself could be damaged or defective. Try connecting the monitor to another computer to see if the problem goes away or remains.
Hopefully, this will help you figure out what’s causing the flickering issues with your monitor. If you have any questions, feel free to comment. Enjoy!
There has been a massive surge in the focus on ‘flicker-free’ monitors from many manufacturers since this list was first introduced on TFTCentral. As a result, we have now retired this page. You should see flicker free listed against modern monitors in the manufacturer specs, and we will continue to test and validate those claims in any reviews we do. Other monitor websites now test for flickering and PWM as well.
i hope you can help me and my friend are doing a project that requires us to update the 240x240 lcd and what ever we try we are not able to get rid of the flicker can you help us fix this ?
//#define ILI9488_DRIVER // WARNING: Do not connect ILI9488 display SDO to MISO if other devices share the SPI bus (TFT SDO does NOT tristate when CS is high)
In this Arduino touch screen tutorial we will learn how to use TFT LCD Touch Screen with Arduino. You can watch the following video or read the written tutorial below.
As an example I am using a 3.2” TFT Touch Screen in a combination with a TFT LCD Arduino Mega Shield. We need a shield because the TFT Touch screen works at 3.3V and the Arduino Mega outputs are 5 V. For the first example I have the HC-SR04 ultrasonic sensor, then for the second example an RGB LED with three resistors and a push button for the game example. Also I had to make a custom made pin header like this, by soldering pin headers and bend on of them so I could insert them in between the Arduino Board and the TFT Shield.
Here’s the circuit schematic. We will use the GND pin, the digital pins from 8 to 13, as well as the pin number 14. As the 5V pins are already used by the TFT Screen I will use the pin number 13 as VCC, by setting it right away high in the setup section of code.
I will use the UTFT and URTouch libraries made by Henning Karlsen. Here I would like to say thanks to him for the incredible work he has done. The libraries enable really easy use of the TFT Screens, and they work with many different TFT screens sizes, shields and controllers. You can download these libraries from his website, RinkyDinkElectronics.com and also find a lot of demo examples and detailed documentation of how to use them.
After we include the libraries we need to create UTFT and URTouch objects. The parameters of these objects depends on the model of the TFT Screen and Shield and these details can be also found in the documentation of the libraries.
So now I will explain how we can make the home screen of the program. With the setBackColor() function we need to set the background color of the text, black one in our case. Then we need to set the color to white, set the big font and using the print() function, we will print the string “Arduino TFT Tutorial” at the center of the screen and 10 pixels down the Y – Axis of the screen. Next we will set the color to red and draw the red line below the text. After that we need to set the color back to white, and print the two other strings, “by HowToMechatronics.com” using the small font and “Select Example” using the big font.
In this guide we’re going to show you how you can use the 1.8 TFT display with the Arduino. You’ll learn how to wire the display, write text, draw shapes and display images on the screen.
The 1.8 TFT is a colorful display with 128 x 160 color pixels. The display can load images from an SD card – it has an SD card slot at the back. The following figure shows the screen front and back view.
This module uses SPI communication – see the wiring below . To control the display we’ll use the TFT library, which is already included with Arduino IDE 1.0.5 and later.
The TFT display communicates with the Arduino via SPI communication, so you need to include the SPI library on your code. We also use the TFT library to write and draw on the display.
The 1.8 TFT display can load images from the SD card. To read from the SD card you use the SD library, already included in the Arduino IDE software. Follow the next steps to display an image on the display:
In this guide we’ve shown you how to use the 1.8 TFT display with the Arduino: display text, draw shapes and display images. You can easily add a nice visual interface to your projects using this display.
This new library is a standalone library that contains the TFT driver as well as the graphics functions and fonts that were in the GFX library. This library has significant performance improvements when used with an UNO (or ATmega328 based Arduino) and MEGA.
Examples are included with the library, including graphics test programs. The example sketch TFT_Rainbow_one shows different ways of using the font support functions. This library now supports the "print" library so the formatting features of the "print" library can be used, for example to print to the TFT in Hexadecimal, for example:
In the library Font 0 (GLCD font), 2, 4, 6 and 8 are enabled. Edit the Load_fonts.h file within the library folder to enable/disable fonts to save space.
TFT_ILI9341 library updated on 1st July 2015 to version 12, this latest version is attached here to step 8:Minor bug when rendering letter "T" in font 4 without background fixed
In this guide we’re going to show you how you can use the 1.8 TFT display with the Arduino. You’ll learn how to wire the display, write text, draw shapes and display images on the screen.
The 1.8 TFT is a colorful display with 128 x 160 color pixels. The display can load images from an SD card – it has an SD card slot at the back. The following figure shows the screen front and back view.
This module uses SPI communication – see the wiring below . To control the display we’ll use the TFT library, which is already included with Arduino IDE 1.0.5 and later.
The TFT display communicates with the Arduino via SPI communication, so you need to include the SPI library on your code. We also use the TFT library to write and draw on the display.
The 1.8 TFT display can load images from the SD card. To read from the SD card you use the SD library, already included in the Arduino IDE software. Follow the next steps to display an image on the display:
In this guide we’ve shown you how to use the 1.8 TFT display with the Arduino: display text, draw shapes and display images. You can easily add a nice visual interface to your projects using this display.
This new library is a standalone library that contains the TFT driver as well as the graphics functions and fonts that were in the GFX library. This library has significant performance improvements when used with an UNO (or ATmega328 based Arduino) and MEGA.
Examples are included with the library, including graphics test programs. The example sketch TFT_Rainbow_one shows different ways of using the font support functions. This library now supports the "print" library so the formatting features of the "print" library can be used, for example to print to the TFT in Hexadecimal, for example:
In the library Font 0 (GLCD font), 2, 4, 6 and 8 are enabled. Edit the Load_fonts.h file within the library folder to enable/disable fonts to save space.
TFT_ILI9341 library updated on 1st July 2015 to version 12, this latest version is attached here to step 8:Minor bug when rendering letter "T" in font 4 without background fixed
A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls.
The display in modern monitors is typically an LCD with LED backlight, having by the 2010s replaced CCFL backlit LCDs. Before the mid-2000s,CRT. Monitors are connected to the computer via DisplayPort, HDMI, USB-C, DVI, VGA, or other proprietary connectors and signals.
Originally, computer monitors were used for data processing while television sets were used for video. From the 1980s onward, computers (and their monitors) have been used for both data processing and video, while televisions have implemented some computer functionality. In the 2000s, the typical display aspect ratio of both televisions and computer monitors has changed from 4:3 to 16:9.
Modern computer monitors are mostly interchangeable with television sets and vice versa. As most computer monitors do not include integrated speakers, TV tuners, nor remote controls, external components such as a DTA box may be needed to use a computer monitor as a TV set.
Early electronic computer front panels were fitted with an array of light bulbs where the state of each particular bulb would indicate the on/off state of a particular register bit inside the computer. This allowed the engineers operating the computer to monitor the internal state of the machine, so this panel of lights came to be known as the "monitor". As early monitors were only capable of displaying a very limited amount of information and were very transient, they were rarely considered for program output. Instead, a line printer was the primary output device, while the monitor was limited to keeping track of the program"s operation.
Multiple technologies have been used for computer monitors. Until the 21st century most used cathode-ray tubes but they have largely been superseded by LCD monitors.
The first computer monitors used cathode-ray tubes (CRTs). Prior to the advent of home computers in the late 1970s, it was common for a video display terminal (VDT) using a CRT to be physically integrated with a keyboard and other components of the workstation in a single large chassis, typically limiting them to emulation of a paper teletypewriter, thus the early epithet of "glass TTY". The display was monochromatic and far less sharp and detailed than on a modern monitor, necessitating the use of relatively large text and severely limiting the amount of information that could be displayed at one time. High-resolution CRT displays were developed for specialized military, industrial and scientific applications but they were far too costly for general use; wider commercial use became possible after the release of a slow, but affordable Tektronix 4010 terminal in 1972.
Some of the earliest home computers (such as the TRS-80 and Commodore PET) were limited to monochrome CRT displays, but color display capability was already a possible feature for a few MOS 6500 series-based machines (such as introduced in 1977 Apple II computer or Atari 2600 console), and the color output was a speciality of the more graphically sophisticated Atari 800 computer, introduced in 1979. Either computer could be connected to the antenna terminals of an ordinary color TV set or used with a purpose-made CRT color monitor for optimum resolution and color quality. Lagging several years behind, in 1981 IBM introduced the Color Graphics Adapter, which could display four colors with a resolution of 320 × 200 pixels, or it could produce 640 × 200 pixels with two colors. In 1984 IBM introduced the Enhanced Graphics Adapter which was capable of producing 16 colors and had a resolution of 640 × 350.
By the end of the 1980s color progressive scan CRT monitors were widely available and increasingly affordable, while the sharpest prosumer monitors could clearly display high-definition video, against the backdrop of efforts at HDTV standardization from the 1970s to the 1980s failing continuously, leaving consumer SDTVs to stagnate increasingly far behind the capabilities of computer CRT monitors well into the 2000s. During the following decade, maximum display resolutions gradually increased and prices continued to fall as CRT technology remained dominant in the PC monitor market into the new millennium, partly because it remained cheaper to produce.
There are multiple technologies that have been used to implement liquid-crystal displays (LCD). Throughout the 1990s, the primary use of LCD technology as computer monitors was in laptops where the lower power consumption, lighter weight, and smaller physical size of LCDs justified the higher price versus a CRT. Commonly, the same laptop would be offered with an assortment of display options at increasing price points: (active or passive) monochrome, passive color, or active matrix color (TFT). As volume and manufacturing capability have improved, the monochrome and passive color technologies were dropped from most product lines.
The first standalone LCDs appeared in the mid-1990s selling for high prices. As prices declined they became more popular, and by 1997 were competing with CRT monitors. Among the first desktop LCD computer monitors was the Eizo FlexScan L66 in the mid-1990s, the SGI 1600SW, Apple Studio Display and the ViewSonic VP140vision science remain dependent on CRTs, the best LCD monitors having achieved moderate temporal accuracy, and so can be used only if their poor spatial accuracy is unimportant.
High dynamic range (HDR)television series, motion pictures and video games transitioning to widescreen, which makes squarer monitors unsuited to display them correctly.
Organic light-emitting diode (OLED) monitors provide most of the benefits of both LCD and CRT monitors with few of their drawbacks, though much like plasma panels or very early CRTs they suffer from burn-in, and remain very expensive.
Radius of curvature (for curved monitors) - is the radius that a circle would have if it had the same curvature as the display. This value is typically given in millimeters, but expressed with the letter "R" instead of a unit (for example, a display with "3800R curvature" has a 3800mm radius of curvature.
Dot pitch represents the distance between the primary elements of the display, typically averaged across it in nonuniform displays. A related unit is pixel pitch, In LCDs, pixel pitch is the distance between the center of two adjacent pixels. In CRTs, pixel pitch is defined as the distance between subpixels of the same color. Dot pitch is the reciprocal of pixel density.
Pixel density is a measure of how densely packed the pixels on a display are. In LCDs, pixel density is the number of pixels in one linear unit along the display, typically measured in pixels per inch (px/in or ppi).
Contrast ratio is the ratio of the luminosity of the brightest color (white) to that of the darkest color (black) that the monitor is capable of producing simultaneously. For example, a ratio of 20,000∶1 means that the brightest shade (white) is 20,000 times brighter than its darkest shade (black). Dynamic contrast ratio is measured with the LCD backlight turned off. ANSI contrast is with both black and white simultaneously adjacent onscreen.
Color depth - measured in bits per primary color or bits for all colors. Those with 10bpc (bits per channel) or more can display more shades of color (approximately 1 billion shades) than traditional 8bpc monitors (approximately 16.8 million shades or colors), and can do so more precisely without having to resort to dithering.
Viewing angle is the maximum angle at which images on the monitor can be viewed, without subjectively excessive degradation to the image. It is measured in degrees horizontally and vertically.
Refresh rate is (in CRTs) the number of times in a second that the display is illuminated (the number of times a second a raster scan is completed). In LCDs it is the number of times the image can be changed per second, expressed in hertz (Hz). Determines the maximum number of frames per second (FPS) a monitor is capable of showing. Maximum refresh rate is limited by response time.
Response time is the time a pixel in a monitor takes to change between two shades. The particular shades depend on the test procedure, which differs between manufacturers. In general, lower numbers mean faster transitions and therefore fewer visible image artifacts such as ghosting. Grey to grey (GtG), measured in milliseconds (ms).
On two-dimensional display devices such as computer monitors the display size or view able image size is the actual amount of screen space that is available to display a picture, video or working space, without obstruction from the bezel or other aspects of the unit"s design. The main measurements for display devices are: width, height, total area and the diagonal.
With the introduction of flat panel technology, the diagonal measurement became the actual diagonal of the visible display. This meant that an eighteen-inch LCD had a larger viewable area than an eighteen-inch cathode-ray tube.
Estimation of monitor size by the distance between opposite corners does not take into account the display aspect ratio, so that for example a 16:9 21-inch (53 cm) widescreen display has less area, than a 21-inch (53 cm) 4:3 screen. The 4:3 screen has dimensions of 16.8 in × 12.6 in (43 cm × 32 cm) and area 211 sq in (1,360 cm2), while the widescreen is 18.3 in × 10.3 in (46 cm × 26 cm), 188 sq in (1,210 cm2).
Until about 2003, most computer monitors had a 4:3 aspect ratio and some had 5:4. Between 2003 and 2006, monitors with 16:9 and mostly 16:10 (8:5) aspect ratios became commonly available, first in laptops and later also in standalone monitors. Reasons for this transition included productive uses for such monitors, i.e. besides Field of view in video games and movie viewing, are the word processor display of two standard letter pages side by side, as well as CAD displays of large-size drawings and application menus at the same time.LCD monitors and the same year 16:10 was the mainstream standard for laptops and notebook computers.
In 2011, non-widescreen displays with 4:3 aspect ratios were only being manufactured in small quantities. According to Samsung, this was because the "Demand for the old "Square monitors" has decreased rapidly over the last couple of years," and "I predict that by the end of 2011, production on all 4:3 or similar panels will be halted due to a lack of demand."
The resolution for computer monitors has increased over time. From 280 × 192 during the late 1970s, to 1024 × 768 during the late 1990s. Since 2009, the most commonly sold resolution for computer monitors is 1920 × 1080, shared with the 1080p of HDTV.2560 × 1600 at 30 in (76 cm), excluding niche professional monitors. By 2015 most major display manufacturers had released 3840 × 2160 (4K UHD) displays, and the first 7680 × 4320 (8K) monitors had begun shipping.
Every RGB monitor has its own color gamut, bounded in chromaticity by a color triangle. Some of these triangles are smaller than the sRGB triangle, some are larger. Colors are typically encoded by 8 bits per primary color. The RGB value [255, 0, 0] represents red, but slightly different colors in different color spaces such as Adobe RGB and sRGB. Displaying sRGB-encoded data on wide-gamut devices can give an unrealistic result.Exif metadata in the picture. As long as the monitor gamut is wider than the color space gamut, correct display is possible, if the monitor is calibrated. A picture which uses colors that are outside the sRGB color space will display on an sRGB color space monitor with limitations.Color management is needed both in electronic publishing (via the Internet for display in browsers) and in desktop publishing targeted to print.
Most modern monitors will switch to a power-saving mode if no video-input signal is received. This allows modern operating systems to turn off a monitor after a specified period of inactivity. This also extends the monitor"s service life. Some monitors will also switch themselves off after a time period on standby.
Most modern monitors have two different indicator light colors wherein if video-input signal was detected, the indicator light is green and when the monitor is in power-saving mode, the screen is black and the indicator light is orange. Some monitors have different indicator light colors and some monitors have blinking indicator light when in power-saving mode.
Many monitors have other accessories (or connections for them) integrated. This places standard ports within easy reach and eliminates the need for another separate hub, camera, microphone, or set of speakers. These monitors have advanced microprocessors which contain codec information, Windows interface drivers and other small software which help in proper functioning of these functions.
Monitors that feature an aspect ratio greater than 2:1 (for instance, 21:9 or 32:9, as opposed to the more common 16:9, which resolves to 1.77:1).Monitors with an aspect ratio greater than 3:1 are marketed as super ultrawide monitors. These are typically massive curved screens intended to replace a multi-monitor deployment.
These monitors use touching of the screen as an input method. Items can be selected or moved with a finger, and finger gestures may be used to convey commands. The screen will need frequent cleaning due to image degradation from fingerprints.
Some displays, especially newer flat panel monitors, replace the traditional anti-glare matte finish with a glossy one. This increases color saturation and sharpness but reflections from lights and windows are more visible. Anti-reflective coatings are sometimes applied to help reduce reflections, although this only partly mitigates the problem.
Most often using nominally flat-panel display technology such as LCD or OLED, a concave rather than convex curve is imparted, reducing geometric distortion, especially in extremely large and wide seamless desktop monitors intended for close viewing range.
Newer monitors are able to display a different image for each eye, often with the help of special glasses and polarizers, giving the perception of depth. An autostereoscopic screen can generate 3D images without headgear.
A combination of a monitor with a graphics tablet. Such devices are typically unresponsive to touch without the use of one or more special tools" pressure. Newer models however are now able to detect touch from any pressure and often have the ability to detect tool tilt and rotation as well.
The option for using the display as a reference monitor; these calibration features can give an advanced color management control for take a near-perfect image.
Raw monitors are raw framed LCD monitors, to install a monitor on a not so common place, ie, on the car door or you need it in the trunk. It is usually paired with a power adapter to have a versatile monitor for home or commercial use.
A desktop monitor is typically provided with a stand from the manufacturer which lifts the monitor up to a more ergonomic viewing height. The stand may be attached to the monitor using a proprietary method or may use, or be adaptable to, a VESA mount. A VESA standard mount allows the monitor to be used with more after-market stands if the original stand is removed. Stands may be fixed or offer a variety of features such as height adjustment, horizontal swivel, and landscape or portrait screen orientation.
A fixed rack mount monitor is mounted directly to the rack with the flat-panel or CRT visible at all times. The height of the unit is measured in rack units (RU) and 8U or 9U are most common to fit 17-inch or 19-inch screens. The front sides of the unit are provided with flanges to mount to the rack, providing appropriately spaced holes or slots for the rack mounting screws. A 19-inch diagonal screen is the largest size that will fit within the rails of a 19-inch rack. Larger flat-panels may be accommodated but are "mount-on-rack" and extend forward of the rack. There are smaller display units, typically used in broadcast environments, which fit multiple smaller screens side by side into one rack mount.
A stowable rack mount monitor is 1U, 2U or 3U high and is mounted on rack slides allowing the display to be folded down and the unit slid into the rack for storage as a drawer. The flat display is visible only when pulled out of the rack and deployed. These units may include only a display or may be equipped with a keyboard creating a KVM (Keyboard Video Monitor). Most common are systems with a single LCD but there are systems providing two or three displays in a single rack mount system.
A panel mount computer monitor is intended for mounting into a flat surface with the front of the display unit protruding just slightly. They may also be mounted to the rear of the panel. A flange is provided around the screen, sides, top and bottom, to allow mounting. This contrasts with a rack mount display where the flanges are only on the sides. The flanges will be provided with holes for thru-bolts or may have studs welded to the rear surface to secure the unit in the hole in the panel. Often a gasket is provided to provide a water-tight seal to the panel and the front of the screen will be sealed to the back of the front panel to prevent water and dirt contamination.
An open frame monitor provides the display and enough supporting structure to hold associated electronics and to minimally support the display. Provision will be made for attaching the unit to some external structure for support and protection. Open frame monitors are intended to be built into some other piece of equipment providing its own case. An arcade video game would be a good example with the display mounted inside the cabinet. There is usually an open frame display inside all end-use displays with the end-use display simply providing an attractive protective enclosure. Some rack mount monitor manufacturers will purchase desktop displays, take them apart, and discard the outer plastic parts, keeping the inner open-frame display for inclusion into their product.
According to an NSA document leaked to Der Spiegel, the NSA sometimes swaps the monitor cables on targeted computers with a bugged monitor cable in order to allow the NSA to remotely see what is being displayed on the targeted computer monitor.
Van Eck phreaking is the process of remotely displaying the contents of a CRT or LCD by detecting its electromagnetic emissions. It is named after Dutch computer researcher Wim van Eck, who in 1985 published the first paper on it, including proof of concept. Phreaking more generally is the process of exploiting telephone networks.
Masoud Ghodrati, Adam P. Morris, and Nicholas Seow Chiang Price (2015) The (un)suitability of modern liquid crystal displays (LCDs) for vision research. Frontiers in Psychology, 6:303.