Alpha 220 LED Sign

You can find one of these signs for less than $100.

220 Full Matrix, (Case 37.7" x 3.8" x 2.9 ") Tricolor

Install a Serial Port Interface

I this case a KuroBoxPro was used however any Linkstation could be used by accessing the serial port interface.

First you are going to have to install a serial port interface. There are two physical serial ports on the KuroBox. One serial port on the bottom which is the same as the port on the Linkstation Pro and one on the daughterboard accessible from the front. Both are addressed as /dev/ttyS0. Consider soldering in a pinheader rather than the pressure connector used in the method described in the LSPRO method.

The cheapest TTL/RS232 converter found was from futurelec, however the order is shipped from thailand so it takes 2-3 weeks to get it. http://www.futurlec.com/Mini_RS232_TTL_3V.shtml

The sign uses a 6 conductor RJ-12 Jack. A Quick port RJ-12 jack is used to interface the sign to the serial port converter

The serial port board/connector are then enclosed in a 2 port Quick port surface mount housing

Interface Sign to Serial Port Interface

A standard 6 wire telephone cable meant for a two line phone is used (a 4 wire one will not work) Plug one end into the sign, and one end into the Quick port RJ-12 Jack. Wire the jack into the serial port board as such

Pin 4 of the RJ12 to RS-232 RX. Pin 3 of the RJ12 to RS-232 TX Pin 6 of the RJ12 to RS-232 GND

Setup the serial port

Adjust the serial port settings, below is a script to do this. This information comes from a FAQ on using the Alpha sign with Linux.

setledsign

# /usr/local/bin/setledsign
#!/bin/sh

rm /dev/alpha
ln -s /dev/ttyS0 /dev/alpha
chmod a+rw /dev/alpha
stty 9600 -opost -ocrnl -onlcr cs7 parenb -parodd < /dev/alpha

Wake up the sign and display something on it

alphamon.pl

# alphamon.pl
#
#!/usr/bin/perl
#
# Script will display the contents of /tmp/textfile to the ALPHA 220C LED
# Display
#
# Usage
#
# alphamon.pl [MODE TAG] [COLORTAG]


# Get the attention of the sign
print "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";


# Tell the sign to print the message
$message = `cat /tmp/textfile` ;

print "\001" . "Z" . "00" . "\002" . "AA" . "\x1B" . " $ARGV[0]" . "\x1C" . "$ARGV[1]" . $message . "\004";

Alpha Sign Syntax

"\001"	"Z"	"00"	"\002"	"AA"	"\x1B"	"t"	"\x1C"	"1"	Hello World	"\004"

Value	Meaning	Code Type
\001	SOH	Start of Header
Z	Direct at all Signs	Type Code
00	All Signs Should Listen	Sign Address
\002	Start of Text Character	Start Type
A	Text File	Write File Type
A	A	File Label
\x1B	ESC	Start of Mode Field
t	compressed text	MODE TAG (see below)
\x1C	color control code	Control Code
1	red	COLORTAG (see below)
Hello World		Text Message
\004	EOT	End of Transmission

MODE TAG and COLORTAG

The key parts of this are the MODE TAG and COLORTAG, there is full documentation available for this but here are the pertinent parts.

MODE TAG a Regular smooth scroll, right to left b Appear. Centers as much of message on screen, waits, and displays rest of message in similar manner c Appear with flashing. d Auto. Randomly picks an effect for each part of the message, as opposed to the message as a whole. e Scroll up. f Scroll down from top. g Jerky scroll from right to left. h Jerky scroll from left to right. i Wipe up from bottom, covering text. j Wipe down from top, covering text. k Wipe over from right to left, character by character, not by pixels. l Wipe over from left to right, character by character. m Scroll up. Same as 'e'? n This is doing something weird based on message itself. Will have to investigate. o Auto/Random (same as 'd'?) p --> CENTER <-- Text appears at sides and squishes content in. q <-- CENTER --> Text splits in center and pushed content out. r --> COVER <-- New text covers old out to in. s <-- UNCOVER --> New text uncovers in to out. t Compressed text! Using this mode the sign tricks your eyes into seeing more characters than it is capable of physically producing. Scrolls right to left. u Fast Appear. v Medium Appear. w Maybe medium-slow appear. x Same as 'p'? y Same as 'q'? z Same as 'r'? @ The sign went blank.

COLORTAG 1 Red 2 Green 3 Amber 4 Dim red 5 Dim green 6 Brown 7 Orange 8 Yellow 9 Rainbow 1 A Rainbow 2 B Color mix C Autocolor Stock Ticker The sign can be used for a number of purposes (to display weather forecasts from an RSS feed, to display news feeds as a news ticker) As a proof of concept the following script uses the sign to display a stock ticker that gets it's data from yahoo. It then colors the prices green if they are positive/up and red if they are negative/down for the day. First install perl and make apt-get install perl make Then install the quote package wget http://www.circlemud.org/pub/jelson/quote/quote-0.05.tar.gz tar -xvzf quote-0.05.tar.gz cd quote-0.05 ./configure ./make ./make install install curl and lynx so that they can be used later to get content from the web. apt-get install curl lynx Lastly here is a shell script to display the ticker leddisplay # /usr/local/bin/leddisplay #!/bin/sh # Stock ticker symbols # PTE=/usr/local/bin stocks=" ^DJI ^IXIC ^GSPC " quote $stocks | cut -d"(" -f1 |sed 's/^/\x1C9 \x7F \x1C3 /' | sed '/ -/s/:/\x1C1/g' | sed '/ +/s/:/\x1C2/g' > /tmp/textfile $PTE/alphamon.pl t A > /dev/alpha References