led Welcome sign

newplumber

Senior Member
Hello to you
from me

I started on this led welcome sign beginning of may something 2016 and finally got most of the thing done
now I just need to put it in a box and set it somewhere

anyway I used 11 74hc595 chips which i ran 3 pins for 6 and 3 pins for 5 and 2 pins to clear all on the b.X side of a 20m2
I used cat5 connections because my wires would be a pain to solder if trying to hook every together
plus I can reuse my board if I want to hook up something else
I used all sockets for my ic's just incase one freaks out its easy to change
when i built this sign I knew i was going to have headaches but luckily it was just minor solder flaws and the pc board from (china) had some copper strips touching
my code isn't nothing for perfection but I have it working

here is video of paper in front of the leds
https://www.youtube.com/watch?v=RquPNiVqwUI
 

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westaust55

Moderator
Hello Newplumber,
The video looks good. Well done.

From the photo of the PCB without wires it appears that you have no decoupling capacitors.
It is good practice to put a 0.1 uF (100 nF) ceramic type capacitor across the power supply near the power pins (VCC and Gnd) for each IC.
These capacitors are referred to a decoupling capacitors and help to filter the high frequency electrical noise from the power lines/buses).
The high frequency "noise" comes from the switching being performed as signal logic levels change from 1 to 0 and 0 to 1 within each PICAXE and other logic chip.

I will admit that I don't always show them, or all of them, in my (DIPTRACE) schematics or PEBBLE software board layouts but even on Proto boards still add some decoupling capacitors between the various chips.
 
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newplumber

Senior Member
thanks westaust55 yep your right i never installed any and makes perfect sense
i guess i was in hurry to get it done but i did add two 47uf caps at the 20m2 chip along with the 100 pf or 10 pf which i thought helped
also i would mention if anyone is going to use cat5 8 pin connectors... DO NOT get the 4 pair thinner wire 24 gauge i bought,
it was a pain to crimp the ends since sometimes they can slip two wires into one slot ... and after you crimp ..its garbage
you need 22 gauge cat5 but lucky i bought a ton of connectors and used alot more then thought.
 

newplumber

Senior Member
Hello Newplumber,


From the photo of the PCB without wires it appears that you have no decoupling capacitors.
It is good practice to put a 0.1 uF (100 nF) ceramic type capacitor across the power supply near the power pins (VCC and Gnd) for each IC.
.
once again its thanks to you, how much time you saved me westaust55
I did add caps to the ic's and before i did it i had problems with different parts of my code wanting to restart the 20m2
after i added them caps it works like it should all perfect so now I was able to code more cool things for it but its awesome
to know that little info helps in a big way
 
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