What is Scrolling Message Dispay : Working & Its Applications

Now a day’s message display boards are using at different places like railway stations, public places, universities, colleges, hospitals, general stores, etc for giving information. Scrolling message means sliding text vertically or horizontally. Scrolling doesn’t change the layout of the text but moves the user’s view across what is a large message that is not wholly seen. They can be used to attract the attention of viewers also. Suppose if a message is written horizontally longer than will fit on the screen, it can’t be displayed completely on the screen. By using scrolling message display units the viewers can see the message.

Scrolling Message Display Unit

A scrolling message display unit is having some basic components like display object, message, position, and delay. The display object is used to where the scrolling message will be displayed. The message is a text what the users can see when it is played. The position is the starting location where the message first displays in the display object. The delay is the time duration between when a message ends and starts to appear again for users.

Types of Devices used to Display:

Digital communication technology is more useful for faster applications. Hence digital systems are commonly used for displaying messages. Choosing the right system depends on the intended application. For example in corporate communications plasma displays placed in common areas such as cafeterias and break rooms. On the other hand, manufacturers are looking to improve their point of purchase advertising displays might choose to employ small, lightweight LCD panels in conjunction with traditional product displays. Budget constraints are also taken into consideration. The large displays have a number of options like TVs, LCDs, plasmas, wall projectors, and traditional CRTs. Smaller displays are typically either small LCD or LED or CRT displays.

The CRT (Cathode ray tube) is a vacuum tube containing one or more electron guns and a fluorescent screen to view images. CRT uses an evacuated glass envelope which is large, and fairly heavy. Hence CRTs have been largely suppressed by newer display technologies such as LCD, a plasma display, and OLED.

An LCD is a display device, for displaying characters, images or videos that uses the light modulating properties of liquid crystals. They do not emit light directly. The most commonly used LCDs are Alphanumeric LCDs and graphical LCDs.

Alphanumeric LCDs are used to display numbers and alphabets. The 16×2 intelligent alphanumeric dot matrix displays are capable of displaying 224 different characters and symbols.

The 16×2 character LCDs are having their limitations. They can only display the characters of certain dimensions. The graphical LCDs are thus used to display customized characters and images. The graphical LCDs can be used in many applications. They are used in video games, mobile phones, and lifts as display units. Various graphical LCDs are available in the market with different sizes. In graphical LCDs, messages are displayed in the form of pixels. A normal LCD module found in the embedded system devices can be made as a scrolling display. It can respond to built-in scrolling commands which make the LCD scrolling possible.

LEDs are used due to their small size and low power consumption and catchy colors they emit. Groups of LEDs are used to display the messages. LEDs will be connected like a matrix to display the characters. Moreover, programming has been done to make the message characters move in an appropriate order. The program will require a lot of data memory or program memory space. In such cases, microcontrollers are needed which are having internal memory. Compared to LEDs, LCDs are easy to interface with the microcontrollers for displaying messages and they also become highly cost-effective. But these can’t be observed from a distance and large size displays are very costly.

Using a microcontroller, users not only set the type of message to be displayed but also controls the speed of the message. The displays will be interfaced with any port of the microcontrollers to display the messages. The displaying messages can be stored in external memory devices like EEPROM. Using switches a particular message can be selected to display the message. When the user pressed a particular switch corresponding message which is stored in EEPROM will be sent to the microcontroller. The microcontroller will write the data to the displaying devices which are interfaced with the microcontroller. A microcontroller can display only one character at one time. To displaying more characters switching of the pins must be done with very less time duration. Then users can see the more number of characters at a time.

Circuit Diagram for Displaying Scrolling Messages on Alpha-Numeric Displays using PC

The above circuit can be used for displaying scrolling messages using a PC. The information sent through a PC, which is interfaced with 8051 microcontrollers through MAX 232 interface IC. An external memory connected to the microcontroller stores the information. The continuous scrolling will be displayed using an LCD which is connected to a microcontroller.

Applications of Scrolling Message Displays:

The Scrolling message displays are used for different purposes and there is no definitive list. However, the following are some most commonly used applications.

Public information: For travel users in railway stations and bus stops and traffic signals for specific information.

Film and Televisions: Scrolling is commonly used to display the credits at the end of the films and television programs.

Industry oriented applications: News, corporate messages, health, and safety messages at different organizations.

Along with the Scrolling message display, the wireless electronic notice board is discussed below.

Wireless Electronic Notice Board

Notice Board is an essential thing in any organization or public places to provide the information. In the present situation, the notice/advertisement boards are almost always managed manually. But sticking various notices day-to-day is a difficult/long process. This wastes a lot of time and manpower.

To overcome this problem there are many digital devices and wireless notice boards that are invented so we can leave a message for other people to read and see. In this article, we are going to see about wireless electronic notice board.

Wireless Electronic Notice Board:

The electronic notice board is a modern device that is used to display information on digital devices. In these types of notice boards, we can leave and erase the information for the people to read and see.

The wireless technology has been making enormous advances over recent years. The use of wireless is increasing not only in industrial applications but also for domestic applications in the day by day life.

Now a day’s, the notice boards are using almost wireless electronic notice boards because they save time and manpower. And we can write and delete the information to the people in time using wireless technology through computers, GSM, mobile, etc. A wireless notice board that displays messages sent from the user’s mobile. It has very fewer efforts and maintenance.

Applications:

The wireless electronic notice boards are used in many applications such as offices, educational institutions, and railway stations, etc.

Advantages

• Text can be entered from the remote place
• The information/data cannot be a lot in power failure conditions

Design and Working of Wireless Electronic Notice Board:

The system is designed to display the message received by cell or a modem. Then microcontroller will control the system by using the programming commands. And the messages will display on the LCD. The displaying of the message will depend upon the LCD type we used.

The system consists mainly of the transmitter unit and receiver unit. The transmitter unit mainly consists of GSM Modem for wireless message transfer. And level shifter ICMAX232 for establishing communication with the microcontroller. In the receiver section, an LCD is interfaced to a microcontroller from 8051 families duly powered by a regulated power supply from the mains supply of 230-volt ac.

When a user sends a message from his mobile phone, it is received by a SIM loaded GSM modem at the receiver unit.

• The GSM modem is duly interfaced through level shifter IC for establishing RS232 communication protocol to the microcontroller.
• In this, the male part of the DB9 connector is connected to the GSM modem and the female part is connected to MAX232 level shifter IC.
• It is used to convert RS232 voltage to TTL voltage levels and vice versa. The microcontroller works on the TTL logic levels. Where logic 1 is +5 volts and logic 0 is 0 volts.
• The message which is received from GSM is sent to the microcontroller.
• Then the microcontroller displays it on an electronic notice board which is equipped with an LCD display.

Photo Credit:

• Image of Graphical LCD by daytrade
• Scrolling Message Display by servehosting
• Notice Board by theicehouse