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Using Arduino => Project Guidance => Topic started by: Mlandgraaf on Jan 11, 2013, 04:18 pm

Title: Giant score board
Post by: Mlandgraaf on Jan 11, 2013, 04:18 pm
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
Title: Re: Giant score board
Post by: larryd on Jan 11, 2013, 07:18 pm
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!
Title: Re: Giant score board
Post by: larryd on Jan 11, 2013, 07:25 pm
:smiley-red: Your current requirements would negate an ULN2803.
Title: Re: Giant score board
Post by: Mlandgraaf on Jan 12, 2013, 06:10 pm
So if i send this to someone who makes PCB's it will work properly? The data connections are good?
Title: Re: Giant score board
Post by: tack on Jan 12, 2013, 07:28 pm
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.
Title: Re: Giant score board
Post by: CrossRoads on Jan 13, 2013, 04:52 am
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.
Title: Re: Giant score board
Post by: Mlandgraaf on Jan 30, 2013, 02:23 pm
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
Title: Re: Giant score board
Post by: CrossRoads on Jan 31, 2013, 12:29 am
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);