In: Computer Science
Explain whether this statement is true or false. If false, explain the correct operation. “an LCD segment is given 1 to turn it on and 0 to turn it off, just like the colored LEDs”. Explain whether it’
Explanation
LED
Display devices are the output devices for presentation of information in text or image form. An output device is a thing that provides a way to show information to the outside world. For displaying the information in an appropriate manner these devices must be controlled by some other external devices. Controlling can be done by interfacing these displays with the controlling devices.
Microcontrollers are useful to the extent that they communicate with external devices, such as switches, keypads, displays, memory and even other microcontrollers. Many interfacing techniques have been developed to solve the complex problems for communicating with displays.Some displays can show digits and alphanumeric characters only. Some displays can show images and all type of characters. Most commonly used displays along with microcontrollers are LEDs, LCD, GLCD, and 7-segment displays
Light emitting diode (LED) is the most commonly used device for displaying the status of microcontroller pins. These display devices are commonly used for the indication of alarms, inputs and timers. There are two ways by we can connect LEDs to microcontroller unit. Those two ways are active high logic and active low logic. Active high logic means LED will be ON when port pin is 1 and LED will be OFF when pin is 0. Active high means LED will be OFF when port pin is 1 and LED will be ON when port pin is 0.
LCD
Liquid-crystal display (LCD) is a popular type of technology used in electronic displays. As the name suggests, it’s characterized by the use of liquid-filled crystals to produce images. Because liquid crystals have light-modulating properties, LCDs are particularly effective for this purpose. The liquid crystals don’t necessarily produce the light used to create the images. Rather, they “propagate” light created by a separate device (backlight). To learn more about LCD displays and how they work, keep reading.
While there are several different configurations for LCD displays, most are designed in the same basic manner. They work by using liquid crystals to produce an image. The liquid crystals are embedded into the display screen, and there’s some form of backlight used to illuminate them. The actual liquid crystal display is made of several layers, including a polarized filter and electrodes. When the backlight is activated, it produces light that is somewhat obstructed by the liquid crystals. And this obstruction is essentially what creates the images we see in LCD displays.
Of course, a backlight is an essential component of an LCD display. Without a backlight, an LCD display wouldn’t be able to produce the visible images. Some of the most common types of backlights used in LCD displays include the following: