Please Log in or Register for more.


183 views

1 Answer

Answer :

Liquid Crystal Display:-
An LCD is a low-cost, low power device capable of displaying text and images. LCD's are extremely common in embedded systems since such system often does not have video monitors like those that come standard with desktop systems.
LCD's can be found on numerous common device like watches, copy machine, and calculators.

Basic principle:-
The basic principle of one type of LCD, a reflective LCD, works as follows, first, incoming light passes through a polarizing plate. Next, that polarized light encounters liquid crystal material.
If we excite a region of this material, we cause the material molecules to align, which in turns causes the polarized light to pass through the material. Otherwise, the light does not pass through.
Finally, light that passed through hits a mirror and reflects back, so the excited region appears to light up.
Another type of LCD, an absorption LCD works similarly but uses a block surface instead of a mirror. The surface below the excited regions absorbs light, thus appearing darker than the other regions.
A dot-matrix LCD consists of a matrix of dots that can display alphanumeric characters (letters and digits) as well as other symbols. A common dot-matrix LCD has five column and eight rows of dots for one character. An LCD driver converts input data into the appropriate electrical signals necessary to excite the appropriate LCD dots.

image


  • Each type of LCD may be able to display multiple characters. Each character may be displayed in normal or inverted fashion.
  • The LCD may permit a character to be blinking or may permit display of a cursor indicating the current character (blinking underscore). Such functionality would be difficult for us to implement using the software.
  • Thus we use an LCD controller to provide us with a simple interface to an LCD having 8-data inputs (DB0-DB7) and one enable input.
  • To send a byte to the LCD, we provide a value to the eight inputs and pulse the enable. This byte may be a control word, which instructs the LCD controller to initialize the LCD, clear the display, select the positions of the cursor, brighten the display.
  • Alternately, this byte may be a data word, such as an ASCII characters, instructing the LCD to display the character at the currently selected display position.
  • In this example, the microprocessor is connected to an LCD controller, which in turn is connected to an LCD as shown in fig. The LCD controller receives control words from and performs the corresponding action on the LCD.
  • Once the initialization sequence is done, we can send control words as send actual data to be displayed.
  • When RS is set to low to indicate that the data sent is control word.
  • When RS is high this indicates that the data sent over the communication bus corresponds to a character that is to be displayed.
  • Everytime data is sent whether it is a control word or data, the enable bit must be toggled.
  • By using initialization code the : CD has been set with an 8-bit interface. In addition, the display has been cleared the cursor is in the home position and the cursor moves to the right as data is displayed. The LCD is now ready to be written to.
  • In order to write data, we set RS=1. The actual data we want to write is on DB0-DB7. The write char functions accept a character which will be sent to the LCD controller to display on the LCD.
  • The Enabled LCD function toggles the enables bit and acts as a delay so that the command can be processed and executed.


Like 0 like

Please log in or register to answer this question.

Related Questions


Liquid Crystal Display (LCD)
Last Answer : Liquid Crystal Display (LCD) LCD stands for Liquid Crystal Display. It is a flat panel electronic display device which uses light modulating properties of liquid crystal. ... pixel and passive pixel display do not consist of switch at each pixel.

Show More

119 views 1 answer







LCD Display Resolution
Last Answer : When you go out shopping for a new LCD TV, one of the most important things worth checking is the resolution. What's the use of an LCD when your neighbor's 20-year-old CRT has better resolution and colors? ... 1680 1050 (or WSXGA+) 24 (widescreen): 1920 1200 (or WUXGA+) 30 (widescreen): 2560 1600

Show More

15 views 1 answer







LCD Display Modules
Last Answer : Replacing a damaged LCD monitor is no easy task. LCDs are expensive, and so are their parts or modules. Let's take a look at a notebook computer LCD, for example. If you go ... include matrix type, viewing angle, color support, brightness, contrast ratio, aspect ratio and input ports.

Show More

13 views 1 answer







Is slight LCD burnin completely perminant?
Last Answer : i didn’t know lcd screens burned. . .

Show More

1 view 1 answer







Industrial LCD Displays
Last Answer : Today, while the Internet has managed to steal the attention of millions of people worldwide, many still tend to turn to the TV for some good, old-fashioned quality entertainment. LCDs are in, CRT ... Some of the best manufacturers of industrial LCDs today are Viewsonic, Sony, Dell, LG and Samsung.

Show More

6 views 1 answer







How to Clean an LCD Screen
Last Answer : How to Clean an LCD Screen Liquid crystal display screens, more known as LCD screens, is becoming more and more popular for its higher resolutions and space-saving dimensions. However, like all appliances ... touching the screen, regular cleaning of your LCD screen will keep it doing its job well.

Show More

10 views 1 answer







What resolution display are you using with your computer?
Last Answer : 1280×800 why do you ask?

Show More

1 view 1 answer







Is an 800-lumen light bulb twice as bright as a 400-lumen one?
Last Answer : A lumen is a measure of brightness. In America, incandescent bulbs used to be rated by “candlepower. ” The LED bulbs are much brighter, and are measured by “lumens.” The wattage is not as big a variable, as the brightness. There are conversions for candlepower to lumens online.

Show More

2 views 1 answer







65K Vs. AMOLED. Are they even in the same category?
Last Answer : According to Engadget it sports a TFT LCD, so it sounds like “65K” is indeed something else.

Show More

0 views 1 answer







Why does my work monitor buzz when there's a lot of black on the screen?
Last Answer : Try turning the brightness down on the monitor and see if it goes away.

Show More

1 view 1 answer







LCD stands for _________ A. Light Crystal Display B. Low Crystal Display C. Less Crystal Display D. Liquid Crystal Display
Last Answer : D. Liquid Crystal Display

Show More

1 view 1 answer








Last Answer : Common computation models: Sequential program model Statements, rules for composing statements, semantics for executing them Communicating process model ... Object-oriented model For breaking complex software into simpler, well-defined pieces

Show More

107 views 1 answer








Last Answer : A semaphore is called binary semaphore when its value is 0, it is assumed that it has been taken (or accepted) & when its value is 1, it is assumed that it has been released & no ... that are not themselves reentrant.3. A reentrant function may does not use the hardware in a nonatomic way.

Show More

382 views 1 answer








Last Answer : The main characteristics of an embedded system are:1. Single functioned2. Tightly constrained3. Reactive and real time1. Single functioned:An embedded system usually executes a specific program repeatedly.Ex. Pager ... computer user. But it doesn't result in a system failure.Ex. Digital camera chip

Show More

348 views 1 answer







Define embedded system.
Last Answer : An embedded system is nearly any computing system other than a desktop computer. Embedded systems are hard to define because they cover such a broad range of electronic devices. It has three main components: 1. Hardware 2. Main application software 3. Real time operating system

Show More

123 views 1 answer








Last Answer : Various features of Linux that are used in embedded systems are as follows : Linux is multiuser operating system. Linux is open source and free. Linux can be ... Linux supports handling of errors. Real-time Linux supports the group scheduling functions.

Show More

138 views 1 answer







What is meant by embedded Linux?
Last Answer : Linux is the operating system if we use this operating system in embedded system devices then it is known as embedded Linux. Linux is open source and free.

Show More

72 views 1 answer







What does the liquid crystal display require for computer applications?
Last Answer : An external light source, called a backlight.

Show More

2 views 1 answer







Write short notes on:  1) Phosphor characteristics  2) Liquid crystal display

Show More

425 views 0 answers







How should I display the "Deck Crystal" I purchased so that it reflects light in my studio the same way they did in old ships?
Last Answer : ummm… what was it supposed to do?

Show More

2 views 1 answer







LCD display broken? Anyone recognize the symptoms?
Last Answer : This happened to my boyfriends laptop, exactly the same. It was the light behind it that has gone, it’s a bit fiddly to mend yourself but it’s just the light. I’m not sure the exact name for it. I’ll ask him when he gets home and get back to you, unless you know I mean.

Show More

0 views 1 answer







I took it apart due to a cracked touch glass and the display looks undamaged, but there was some liquid on it. When turned on without glass and touch pad, it glows white.
Last Answer : Need Answer

Show More

1 view 1 answer







Does this machines lcd display need an AC adapter to run or is it powered by batteries?
Last Answer : Tunturi-R30-Rowing-Machine is powered by batteries and does not need an A/C adapter.

Show More

0 views 1 answer







How does an Industrial LCD Display work?
Last Answer : There are many types of industrial lcd displays. here is a link about how touch screen ones operate... http://www.industrial-lcd.com/index.php?option=com_content&view=article&id=21:faq&catid=3:text&Itemid=20#3

Show More

0 views 1 answer







Which of the following is non-emissive display? A. LED B. LCD C. Both (A) and (B) D. None of the Above
Last Answer : B. LCD

Show More

0 views 1 answer







The seven segment arrangement for numerical display on consoles, test meters and other applications can be either ________________. A. UJT or BJT B. BCD or OCD C. JFET or IGFET D. LED or LCD
Last Answer : Answer: D

Show More

5 views 1 answer







Compare CRT and LCD display. 
Last Answer : CRT LCD CRT monitors require about 100 W for 19 display. LCD monitors require 45 W for 19 display. CRT's are heavier than LCD. LCD monitors are lighter and thinner They are ... is possible. CRT displays text is not good as LCD. LCD displays text better than CRTs.

Show More

71 views 2 answers







What is the state of liquid crystal ?
Last Answer : The state in which a substance can flow like a liquid and then acquire a three-dimensional molecular structure like a solid is called liquid crystal state of matter. In this state matter has ... they are used for digital display in various electronic devices such as calculators , thermometers, etc.

Show More

0 views 1 answer







What liquid can I pour into a container to turn what’s inside into a crystal?
Last Answer : I remember seeing an IG video where a guy poured some liquid into a mason jar that had some stuff inside and it solidified and he carved it to look like a crystal. What is the liquid and is it publicly available?

Show More

0 views 1 answer







Glass is - (1) Super cooled liquid (2) Crystalline solid (3) Liquid crystal (4) None of these
Last Answer : (1) Super cooled liquid Explanation: Glass is sometimes called a Super cooled liquid because it does not form a crystalline structure, but instead forms an amorphous solid that allows molecules in the material to continue to move.

Show More

1 view 1 answer







Automatic wrist watches get energy from - (1) twist in spring (2) liquid crystal (3) kinetic energy (4) movement of our hands
Last Answer : (1) twist in spring Explanation: An automatic watch is a watch that continues to operate due to the regular motion of the wearer's wrist.

Show More

2 views 1 answer







Liquid crystal elastomers 4D printing material achieve their activation due to a. Light b. Heat c. Electrical d. All of the above
Last Answer : Ans:- d. All of the above

Show More

6 views 1 answer







Define liquid crystal polymers.
Last Answer : Liquid crystal polymers are a class of aromatic polyester polymers which are capable of forming regions of highly ordered structure (like crystal) even in the liquid phase.

Show More

42 views 1 answer







State the properties of liquid crystal polymer.
Last Answer : 1) They have high mechanical strength at high temperature. 2) They are extreme chemical resistance. 3) They have good weatherability. 4) They are inert. 5) They resist stress, cracking in the ... temperatures. 6) It has high coefficient of thermal expansion. 7) It is highly resistant to fire.

Show More

32 views 1 answer







Define the terms: i) Photo conductive polymers ii) Liquid crystal polymers 
Last Answer : i) Photo conductive polymers: These are the polymers which conduct electricity only in the presence of light.  ii) Liquid crystal polymers: These are a class of aromatic polyester polymers. These polymers have tendency to align their chains parallel over a long distance from their melt or solution.

Show More

26 views 1 answer








Last Answer : A design metric is a measure of a implementations features such as cost, size, performance and power.Commonly used design metrics are:1.NRE cost:NRE stands for non recurring engineering cost. ... to check that manufacturing was correct.11.Safety:The probability that the system will not cause harm.

Show More

138 views 1 answer







What is a hard real time system?
Last Answer : If the real-time systems have minimum interrupt latency and task deadline with prescribe time limits then it is known as hard real-time systems.  If these two requirements meet in real time systems but not always then it is known as soft real-time systems.

Show More

125 views 1 answer







Normally, the FPGA resources are used less than 70% because:  a. Routing becomes excessively complicated b. Power issues c. Clock frequency d. Simulation time increases
Last Answer : Normally, the FPGA resources are used less than 70% because: Routing becomes excessively complicated

Show More

320 views 1 answer







83 views 0 answers







77 views 0 answers







List and describe three general approaches to improve designer productivity.
Last Answer : Automation: The task of using a computer program to replace manual design effort. The program replaces manual design effort. Synthesis. Reuse: The ... correctness/completeness of each design step. Hardware/software co-simulation.

Show More

109 views 1 answer







Explain placement, routing, and sizing.
Last Answer : Placement: The task of placing and orienting every transistor somewhere on IC. Routing: The task of running wires between the transistors without inserting other wires or transistors. ... wires and transistor provide better performance but consume more power and require more silicon area.

Show More

78 views 1 answer







A single FSM can be converted to two smaller FSM. Justify.

Show More

591 views 0 answers







Sketch internal design of 4x3 ROM.
Last Answer : The internal design of 4x3 ROM

Show More

779 views 1 answer







Explain the advantages and disadvantages of using memory I/O and standard I/O.
Last Answer : Memory mapped I/O and standard I/O are the two methods for communicating microprocessor with peripherals. Processor talks to both memory and peripheral using the same bus.Two ways to talk to a peripheral. ... of standard I/O is no loss of memory addresses to the use as I/O addresses.

Show More

171 views 1 answer







Explain parallel and wireless protocols.
Last Answer : Parallel protocols: PCI bus (Peripheral Components Interconnect): PCI stands for Peripheral Components Interconnect. PCI bus is used as a communication line to transmit signals and data ... provide the basis for wireless network products using the Wi-Fi brand.

Show More

100 views 1 answer







Explain memory hierarchy.
Last Answer : Memory hierarchy: Main memory is large, inexpensive, slow memory stores entire program and data. Cache memory is small, expensive, fast memory stores copy of likely accessed parts of large ... In memory hierarchy the smaller memory is faster and larger memory storage is slower.

Show More

186 views 1 answer







Explain memory write ability and storage permanence with suitable diagram.
Last Answer : Write ability and storage permanence of memories: Write ability is the manner and speed at which memory can be written. Storage permanence is the ability of memory to hold stored bits ... Holds bits after power is no longer supplied. High end and middle range of storage permanence.

Show More

3.5k views 1 answer







Describe different RT level computational and sequential components used to design single function processors.
Last Answer : RT-level combinational components:- To reduce the complexity in digital logic, combinational components are used, which are more powerful than logic gates.  Such combinational ... during a clock edge. An asynchronous inputs value effects the circuit independent of the clock.

Show More

244 views 1 answer







Build using minimum number of CMOS gates. Three input NAND gate. Two input NOR gate Three input NOR gate Two input AND gate Two input OR gate
Last Answer : Three input NAND gate. Two input NOR gate Three input NOR gate Two input AND gate Two input OR gate

Show More

213 views 1 answer






Show More⇦ PreviousNext ⇨