Alpha 220 LED Sign

From NAS-Central Buffalo - The Linkstation Wiki

Revision as of 00:10, 10 August 2007

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

220 Full Matrix, (Case 37.7" x 3.8" x 2.9 ") Tricolor[1]

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.

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^[2]

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^[3].

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

MODE TAG and COLORTAG

The key parts of this are the MODE TAG and COLORTAG, there is full documentation available for this^[4] but here are the pertinent parts.

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 ^[5]

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

1. ↑ 220 brochure (Pdf)
2. ↑ Building a Data Cable for Alpha LED Scrolling Signs
3. ↑ Using the Alpha 215C with Linux
4. ↑ Alpha Sign Communications Protocol (pn 9708-8061)
5. ↑ quote -- command-line stock quote display