FINAL YEAR PROJECT 1 (WEEK 12): LCD Display

Objectives:

1) To study about LCD display

2) To know the application of LCD display

Method:

1) By making research in the internet

A liquid-crystal display (LCD) is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals. Liquid crystals do not emit light directly. LCDs are available to display arbitrary images or fixed images with low information content which can be displayed or hidden such as preset words, digits and 7-segment displays as in a digital clock. they use the same basic technology except that arbitrary images are mafe up of a larger number of small pixels while other displays have larger elements.

There are important factors to consider when evaluating an LCD:

• Resolution vs. Range: Fundamentally resolution is the granularity with which a performance feature of the display divided. Resolution is often confused with range or the total end-to-end output of the display. Each of the major features of a display has both a resolution and a range that are tied to each other but very different. Frequently the range is an inherent limitation of the display while the resolution is a function of the electronics that make the display work.
• Spatial performance: LCDs come in only one size for a variety of applications and a variety of resolutions within each of those applications. LCD spatial performance is also sometimes described in terms of the diagonal distance from one corner to its opposite. The spatial resolution of an LCD is expressed by the number of columns and rows of pixels. 
• Temporal/timing performance: As compared to spatial performance, temporal performance is a feature where smaller is better. The range is the pixel response time of an LCD or how quickly a sub-pixel's brightness changes from one level to another. REfresh rate or the temporal resolution of an LCD is the number of times per second in which the display draws the data is being given. Since activated LCD pixels do not flash on/off between frames. 
• Color performance: Color performance include color gamut which is the range of colors that can be displayed and color depth which is the color resolution or the resolution or fineness with which the color range is divided. 

LCD display applications:

• Computer monitors
• Televisions
• Instrument panels
• Aircraft cockpit displays
• Signage
• DVD players
• Clocks
• Watches
• Calculators
• Telephones
• Gaming devices

For this project, the LCD display that will used is 16x2 LCD display. This LCD display is much more informative output device than a single LED. The LCD is a display that can easily show characters on its screen. They have a couple of lines to large displays. Some LCDs are specifically designed for specific applications to display graphic images. These modules are replacing 7-segments and other multi-segment LEDs. LCD can be easily interfaced with microcontroller to display a message or status of the device. It can be operated in two modes: 4-bit mode and 8-bit mode. This LCD has two registers namely command register and data register. It is having three selection lines and 8 data lines. By connecting the three selection lines and data lines with the microcontroller, the messages can be displayed on LCD.

LCD display

LCD instructions set for controlling the LCD display using microcontrollers

PIN description

Interfacing 16x2 LCD display with 8051 microcontroller

In the above figure, 3 selected lines EN, R/W, RS will be used for controlling the LCD display. EN pin will be used for enabling the LCD display for communicating with microcontroller, RS with be used for register selection. When RS is set microcontroller will send instructions as data when RS is clear microcontroller will send the instructions as commands. For writing data RW should be 0 and for reading RW should be 1.

Conclusion:

This week I am going to learned about the LCD display as it is the one of the component which is used in my project. The type of LCD display and the application of of it need to take note so that it is suitable to use in this project. This project will used the 16x2 LCD display. The LCD display is used to display the location of the accident, the information whether the rider is drunken or not and display the motorcycle will start or not if the rider does not violated the rules when he or she wearing the helmet.  This will help the rider to get a help in a very short time. Hence, lives can be save.