Free Project - 245 LED Display

[T.Jackson]

Check this out: http://www.symmttm.com/pdf/NYTimes_T...p_09-30-04.pdf
Atomic clock has accuracy of +/- 1 sec over 30 million years.

[T.Jackson]

I've got some much better accuracy now. Not exactly sure how much - only time will "literally" tell!

Here's what I've done to improve things:

<ul>
<li>TMR0 pre-scaler remains @256</li>
<li>TRM0 always starts with 12 dec (256 x 244) = 62.464 mS</li>
<li>Now, it takes 16 overflows of the timer for 0.999424 S to elapse</li>
<li>This is short of 1 sec by 576 uS</li>
<li>Adding 36 nops to each overflow (36 x 16 = 576 uS) compensates this</li>
<li>The crystal now completely defines accuracy</li>
</ul>

[magu]

Look, I feel for you, believe me I do. I know how trying things can be when you're first starting out, I was once a beginner too! If you're that determine to do this project, then my best advice to you is to get some "real-World" help from someone. Or, alternatively, read a book on electronics and PICs. Put the project aside until you've got some considerable more knowledge under your belt. As I've said before, this isn't a simple straight forward project, unless you've got a PCB for it.

ok, i understand , now i have to make the pcb, connect the rez, cap, crystal, transiztors, then the pics (4017, 74hc08, eeprom), and then program the PIC and see if work...

[T.Jackson]

Why don't you put it off for a while - I'm actually planning on doing a KIT for a similar project to this. (Much, much better circuit that does more than just scroll a message) Plus, everything will mount on one large double sided through hole plated board w/silk screen printing on both sides. It will use 8 LED modules rather than the individual LEDs. Today I found a good source for low-cost PCBs. Basically, at the moment, Im in the "planing phase" of things with it, it'll be at least a year away, I need to save up some funds.

[magu]

Why don't you put it off for a while - I'm actually planning on doing a KIT for a similar project to this. (Much, much better circuit that does more than just scroll a message) Plus, everything will mount on one large double sided through hole plated board w/silk screen printing on both sides. It will use 8 LED modules rather than the individual LEDs. Today I found a good source for low-cost PCBs. Basically, at the moment, Im in the "planing phase" of things with it, it'll be at least a year away, I need to save up some funds.

today i`m making the pcb in orcad layout... and tomorow i will finish this pcb... then i see if it work or not...best regards...