Post your projects: a lot more licking then you'd think

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Post your projects: a lot more licking then you'd think

easyjo: Nov 4, 2004; fleeee!

An earlier project of mine was replacing a BBC Master innards with a Compaq Ipaq machine to run linux.

Insides:

Removal:

Ipaq parts

The main issue was rewiring the keyboard to work with a PS2 keyboard controller (which I took from an old keyboard). Once it was wired up, and all the keys gave an output, a keymap file had to be made. Once that was sorted I can now use the keyboard full time!

Recent Project:

LED Display. I recently got an LED display as I saw one at a great price. Primarily for displays RSS feeds, etc. The display came with some windows software to display messages, and after sorting out the syntax that it used I wrote a little php app that writes to the serial port, allowing whatever message to be displayed.

Although at the moment, it just currently sits on the internet accepting messages:
https://www.easyjo.com/led.php

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easyjo: Nov 4, 2004; fleeee!

Company Mime posted:

Where'd you find that LED display at a good price? Most everywhere I've looked online has wanted an arm and a leg for them.

mine was from https://www.bluearan.co.uk unfortunately they've were getting rid of them and have none left

Although there's usually ones around �100 for a similar size one (1 colour) from ebay.

kyacker posted:

This is awesome. Can you please post a howto? PLEEEEEEEEEEEAAAAAASSSSSSEEEEEEE?

Sure, I've been meaning to write a full writeup so here goes....

The LED display is an RS232 controlled device, with 120*8 pixels (3 colours)...

Software came with the screen which can send it messages, graphics and also play music (no idea why). The first stage of the project was to work out the syntax used by the software so I could replicate it within my own program...

This is the syntax sent to the device for a message of "MESSAGE"

<ID00><BE>05<E><ID00><L1><PA><FE><MA><WC><FE>MESSAGE3F<E><ID00><BF>06<E>

As you can see, it contains various tags, which are for font size, scroll speed, intro effect, out effect etc.. and also, importantly a form of hash/checksum after the message, in this case "3F".

This turns out to be calculated by
$hh = 0x74; for ($i = 0; $i < strlen($text); $i++) { $hh ^= ord($text[$i]); }$hh = dechex($hh);

So now, the message can be sent like follows:

<ID00><BE>05<E><ID00><L1><PA><FE><MA><WC><FE>$text$hh<E><ID00><BF>06<E>

Various keycodes can also be used within the message text such as <CR> etc to display various colours.

All the webpage does is adds a message to a MySQL database and adds it to a queue. Another local app running on my pc, connected to the display using USB->RS232 checks the database every 5 seconds or so and displays the message as required.

Then obviously the webcam captures this image, and uploads it to the site...

Also it seems that most LED devices have very similar syntax to this, some with different tags etc, so I guess there is some form of standard method of programming these displays.

Any more info required, just ask.

Edit also bonus mario and pacman: