LED Clock

May 5th, 2007 · 9 Comments · avr, led

So this is my approach of an LED clock. There are zillions of LED clocks out there. Mine is some kind of retro and minimalistic version. It consists of

AVR ATmega8, 8 Kb, 4.096 MHz
Everlight 2.3″, LED Matrix, 8×5 LEDs
some resistors, capacitors and a quarz
optional serial connection for configuration

The LED matrix is used in landscape mode, that means it uses a very tiny font. Most characters fit in 3×5 pixels. The font supports only uppercase characters. Because the display has only 8 columns the message has to scrolled.

The display has the following features at the moment:

Displays a greeting message
Displays the current time, hh:mm:ss
Displays a custom message
Messages and current time can be modified via serial port

Schematics
Here is the schematic of the LED clock. The Everlight 5*8 Dot Matrix was not available as part of the Eagle libraries, so I build the part on my own. It looks a bit clumsy as it is my first try to design components.

Here is a video of the LED Clock. You can see how it changes through different modes from telling the time to displaying a greetings message.

Click To Play

9 responses so far ↓

1 Alex // Jun 29, 2007 at 11:25

Nice!

I’m mucking around with an LED matrix at the moment myself. I’m a bit stuck on the scrolling though, I can make it scroll one character at a time but it starts at the left hand side, so looks crap. Any possibility of seeing your code? In return, I’ve got an eagle part library for an 8×8 matrix that I’m sure you could alter to a 8×5 easily…
2 Alex // Jun 29, 2007 at 14:31

Hi Alex,

just add more spaces to your string, that should help with the scrolling. The source is unfinished and as always without any warranty.
Anyway, here you go …

matrix.zip
3 jfk // Mar 25, 2008 at 16:56

hey,

may you give me your eagle file for the dot matrix thing? i have a 7×5 one here but no files it anywhere. altering yours would save me a lot of time. =)

greets
4 jfk // Mar 25, 2008 at 16:58

mh, just now i found a similar useful one: http://www.sensi.org/~svo/eagle/
5 jfk // Mar 25, 2008 at 17:03

let me correct myself: not as useful as yours would be..
6 Alex // Mar 29, 2008 at 09:57

Hi jfk,

the part has not been used in a PCB until now so I will not release something untested. It was my first part and it was a bit crappy. I think I will remake it.

Cheers,
Alex
7 Andhika // Jul 26, 2008 at 08:00

I’m sorry, I still don’t understand how to change the clock and messege via serial port. can you give the program or how to change them? And if i add more led matrix, which code should I change?I’m so intersting with this project. My plan is make this project for gift to my girl. can you help me? thanks before.
8 Vlatko // Apr 6, 2010 at 08:07

BTW, what happened to this project Alex? Never finished?
9 Alex // Apr 6, 2010 at 23:20

I often get stuck in prototyping