Here's another project that's been on the cards for a while. I really should have made an LED display before now.
These take fair bit of effort to build, but the first completed to the point of displaying text well within 36 hours.
With the software taken care of, subsequent units took between 8 and ten hours to build on prototype PCBs.

Software I have written for the device include a text message scroller with various effects including sine wave,
the classic Snake game, and also a clone of the classic Tetris game.
There is still plenty of potentially interesting software that could be written for it.
I have decided to share details of this project including hardware and software
allowing anyone with soldering and electronics skills to reproduce it.

The only microcontroller required to drive the display is a pic 16F877A.
An EEPROM chip was initially used for storage of the message content to be displayed,
but some improvement lead to the message being stored in on-chip EEPROM.
The device now has only a single chip, and freeing up the pins previously used for the
external EEPROM chip meant that I could add a PCB speaker, and add sound support!

Circuit Board underside reveals 3 dimensional soldering work on the LED matrix

The above image was not yet completed to the point of having DIP switches or a joystick connector.







Classic Snake game running on a 144 LED display using a Talkbot to reproduce sampled sound

Here is a clone of the classic Snake game I wrote to run on my display.
One of the YouTube videos below show it being played.
I had to make a 4 way joystick peripheral to make gameplay possible.
A Talkbot device was kindly provided by Roman Black
for use in a project of this nature.

A Talkbot makes it easy to add support
for sampled sound playback to microcontroller projects.
I can be controlled over a serial or parallel interface,
depending on which Talkbot firmware is loaded.
I used one of the LED matrix input pins to output
a serial control byte between drawing frames for the game.
The newer design has it's own speaker, but I plan to reimplement
support for the Talkbot.










Details of this project including source code can be found HERE

You may be required to register on the PicBasic Forum before you are allowed to download.

This page was originally created 23/01/10, and last updated 22/02/10.

The YouTube videos below demonstrates the 144 LED Display in action.

The top left video demonstrates a sine wave text message scroller routine which I haven't seen done before
and on the top right, a three part demo includes a non-playable Pong game demo screen.


The bottom left video demonstrates the classic Snake game with support for the Talkbot,
and on the bottom right, a clone of the classic Tetris game.


The video below shows a sequence of photos of the assembly of the yellow LED display.