LED Moving Message Display
Serial UART Input, Easy to use for static and scrolling messages. 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.
- 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.
There 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.
- 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 display
If 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 ASCII string to be scrolled.
Example string on screen would be strings like below,
!TEST STRING <-Enter Key(0x0D, decimal 13)
There 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
To 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.
We recommend this Terminal software which can be used test display by sending serial data from PC side.