Free Project - 245 LED Display

[magu]

i connect the IC3(pin15) to ic7(pin 10) and the LED is moving across the display NOT ONCE but CONTINUOS.

[Dan Cata]

Some people have already built the circuit and it runs just fine for them; i don't think there is a mistake in the schematic and i can't wait for Trent to reply and see what he has to say about this. (i apologise for my bag english)

[T.Jackson]

Luciano is correct. There is an error on the schematic that shows Q0 instead of Q4 of IC7 connecting to the MR (master reset line) of IC3.

[skimask]

Luciano is correct. There is an error on the schematic that shows Q0 instead of Q4 of IC7 connecting to the MR (master reset line) of IC3.

...which might explain why it worked for me.
I only built a portion of this project using only the first 4017. I 'simulated' the rest of the 4017's using some glue logic, specifically, a PIC setup to pick off the clock pulses into the timer on the PIC and generate a reset pulse after it got to the last column.

[Dan Cata]

So Trent, you say the circuit works just fine for you, but the schematic posted was wrong... did you mistake on purpose? Were we suposed to guess the error in it? I also build the circuit and it runs for me until the LED flashing part, now i can see it all so clearly why ...

[Luciano]

Hi,

I don't think so. The PDF file with the schematic is probably just
a version made for the publication in a magazine so this is probably
not the original schematic use by Trent to make his prototype PCB.

* * *

@ skimask: Less arrogance, more humility!


Best regards,

Luciano

[magu]

next step luciano?

[T.Jackson]

That's right. I normally start off with something roughly hand drawn, sometimes nothing on paper at all - working directly off the top of my head, build a prototype then proceed to document it.

[Dan Cata]

How about re-doing the scheme and posting it again, in the first post, if that is possible... , so that anyone trying to build it doesn't face the same problem; maybe they don't read the whole 3 pages of posts to see that there is a problem with it!

[Dan Cata]

But you can see clearly that the pdf is a print from OrCad or something that the circuit was made, so it has to be the one that the pcb was made of!