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Brads Electronic Projects Forum • Beginner PCB design for LED clock
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Beginner PCB design for LED clock

Posted: Thu Nov 29, 2018 12:28 pm
by LouisDong
Hi everyone,

I'm designing an LED clock using an Arduino, 74HC595s for the control, and ULN2803s for grounding the LEDs.

I've got everything working on a breadboard, designed on a schematic and a first version laid out on a pcb in Eagle. I've never designed a pcb before,Usually,PCBGOGO helps me complete the design and production so I'm sure there's lots of little errors.

The main question I have is related to decoupling capacitors and a ground plane. I was having trouble finding out online if the capacitors should have their own pathway to the 74HC595s, or if they could both simply be connected to the ground plane.

I haven't put the ground plane in in this version, and any suggestions overall are much appreciated.

Thanks for any help.

Schematic:
clock-brd-v1.png
clock-brd-v1.png (85.06 KiB) Viewed 8438 times

Re: Beginner PCB design for LED clock

Posted: Fri Nov 30, 2018 8:58 am
by Garth
A small board like that with 74HC logic will be more forgiving than some. The matter of grounding, ground bounce, bypassing, transmission lines, terminations (which you definitely do not need on this board), etc. is complex and is discussed in a 6502.org topic at http://forum.6502.org/viewtopic.php?p=17664#p17664 and the many helpful links there including to some on my site. You are welcome of course to read it, but if you want to join and post, please note that that forum is specifically for the 65xx family of microprocessors. Posts and topics must have some relevance to this family.