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Topic: Giant score board (Read 649 times) previous topic - next topic

Mlandgraaf

Hi Guys,

A few monthes ago i posted about a giant score board that i'm making. So i finished the schematics and was hoping you could check it out, so that i wont be dissapointed when it doenst work!

It's made so you can connect a 10 wire ribbon cable to a series of led strips (330ma 12v each) making a giant 7-segment display.

Looking forward to your criticism!

Thanks

Mike

LarryD

At 1st glance it looks good.
I think I would have used 4 X ULN2803 hex drivers rather than the FETS. This would get rid of 64 discrete components.
http://www.datasheetcatalog.org/datasheets/90/366828_DS.pdf
There are a myriad of ways of doing things though!
The way you have it in your schematic isn't the same as how you have it wired up!

LarryD

:smiley-red: Your current requirements would negate an ULN2803.
The way you have it in your schematic isn't the same as how you have it wired up!

Mlandgraaf

So if i send this to someone who makes PCB's it will work properly? The data connections are good?

tack

You can't just send a schematic, unless someone else is also going to design the PCB for you.

To send a PCB to be made then you need to design it, convert to the appropriate format for the tab house (usually Gerber files) and send them.

CrossRoads

The .pdf seems to try & open a link
http://arduino.cc/forum/index.php?action=dlattach;topic=142154.0;attach=33416
that is not any good.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Mlandgraaf

Can you tell me why i need a pull down resisitor? and what value should it be? I've let someone make a pcb, and it looks perfect!
Also, what capacitor needs to be on the vcc of the shift register?

Thanks

MIke

CrossRoads

0.1uF on the VCC pins.
Pulldown resistor - 10K is fine. Keeps the MOSFETs while the sketch comes out of bootloader and takes control of the IO pins bring them low prior to any data writing, i.e.
pinMode(pinX);
digitalWrite(pinX, LOW);
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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