LED Scrolling Display

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LED Scrolling Display System:Display accepts simple string through uart and implements scrolling of the text on LED Matrix

display. You can connect microcontrollers directly to update the string or connect to PC to send

string to scroll. It supports different scrolling speeds.

It even supports static display of text without scrolling.

Format for sending string is very simple and it can accept maximum of 255 characters of ASCII text.

We have provided sample source code for testing with microcontroller as well as details on testing

with PC terminal software.

Features

48x8(384 LEDs) 5mm dot size LEDs in Matrix format (8 LED height and 48 LED width)

Operates at 5V (800mA max current)

Can connect directly to microcontroller or PC through RS232/USB

Many Scrolling speed supported. Static display of characters without scrolling is possible

Internal buffer for 255 characters display

Sample source code for microcontroller to quick start your application.

PinoutsThere are just three pins to use the display.

RX-IN = Receive Input :

Input serial data of 3-5V logic level, Usually connected to TXD pin of

microcontrollers/PC/RS232.

Note: Do not connect this pin to direct PC serial port without MAX232. It will damage the

display since direct PC serial port has +12V/-12V voltage level.

+5V = Power Input: Regulated 5V supply input. Current has to be capable of atleast 800mA.

GND = Ground level of power supply. Must be common ground with microcontroller.



Specification Operating Votage: Regulated +5V supply required

Operating Current: 800mA Peak - When all LEDs are lit up the display takes 800mA, So

have a provision of that much current. If no LEDs are lit up the display take around 100mA.

Communication Baud Rate: This is the baud rate the board accepts as serial input string.

9600 – 8 bit data – No parity – 1 stop bit – Handshaking NONE

Serial Input, It accepts Serial input baud rate of 3-5V voltage level. Can connect directly to

any microcontroller TXD pins.

Volatile Memory: The display has internal memory for 255 characters. When display is

powered off, the memory is cleared. LED Dots: Width are 48 LEDs across Height has 8 LEDsAll LEDs are made on for a brief

moment(1sec) during power up so you can test the display

Board Dimensions: 362 x 72 mm

Format for setting string to be scrolled on displayIf you wish to set a string for scrolling it can be maximum 255 characters. The baud rate of input to

display is 9600 bps. The string starts with ! exclamation character which is marked as start of string

idenfier. The string ends with CR (Carriage return, '\r', 0x0D, 13 in decimal) which is acting as line

feed character or End of string idenfier. In between the ! and CR are maximum 255 bytes ASCIIstring to be scrolled.

Example string on screen would be strings like below,

!TEST STRING <-Enter Key (0x0D, decim al 13)



Scrolling SpeedThere are many scrolling speed supported by display. You can send HEX values as below to set

scrolling speed.

0xF0 = Static Mode, No scrolling, Dispays the text buffer without scrolling.

0xF1 to 0xFF = You can send any hex values frmo 0xF1 to 0xFF, where 0xF1 is the fastest and

0xFF is the lowest scrolling speed. Default power up speed is medium at 0xFA

PC InterfacingTo connect to PC you can use either a simple MAX232 circuit to convert display’s TTL level of 5V to

RS232 level or you can use a USB to TTL UART board. Either way you can get a serial port on PC

to connect to and send string.

Connecting to RS232 Serial PortUse a MAX232 circuit like below to convert display's 5V level to RS232 level

Connecting to PC's USB PortYou can use a USB to UART adapter to connect to display. Since it takes around 800mA power, Do

not use power from USB. Our USB to Serial TTL UART adapter model 1151 will appear as virtual

serial port on PC to which you can communicate through any software which can transmit receive by

this serial port like hyperterminal or custom made software.

LED Scrolling Display

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