I notice that pin 13 flashes on start up which kind of makes that pin a little useless. Is there any way around that or is that just something one has to live with?
Also what if you want to add more IO ports to the Arduino Uno, is there any kind of add on for that?
Pin 13 is flashed by the serial bootloader when it's invoked during power on and reset. The simple way to prevent this flashing is to use an external programmer to program your Arduino as this will also overwrite the bootloader.
Depending if you need extra inputs or outputs you can use 74HC595 & 74HC165 shift registers to give extra pins.
Riva:
Pin 13 is flashed by the serial bootloader when it's invoked during power on and reset. The simple way to prevent this flashing is to use an external programmer to program your Arduino as this will also overwrite the bootloader.
Depending if you need extra inputs or outputs you can use 74HC595 & 74HC165 shift registers to give extra pins.
Thanks Riva,
Where can I get an external programmer and are they easy to use? Or is it just simpler to not use pin 13? Seems a bit of a waste though.
Also what are the shift registers and how does one use them? And got tutorials out there on how to do this stuff?
Knightriderguy:
Also what are the shift registers and how does one use them? And got tutorials out there on how to do this stuff?
Ever hear of this thing called google? Look here.
Knightriderguy:
I notice that pin 13 flashes on start up which kind of makes that pin a little useless.
Actually, it is very useful. It tells you that it is working. It is intended as a status or "information" LED, you might use it to flash occasionally to tell you that things are working, or what the current state of the system is.
Paul__B:
Actually, it is very useful. It tells you that it is working. It is intended as a status or "information" LED, you might use it to flash occasionally to tell you that things are working, or what the current state of the system is.
Ahh OK good point Paul that makes sense. I guess I could use that LED as like you say an indicator. I looked into those Shift registers... very cool, I'm going to so need to get at least one of those. 
Knightriderguy:
very cool, I'm going to so need to get at least one of those.
If you go to the right place they're cheap as hell. Get a handful. You'll find more uses for them. And it's a real pain paying $5 shipping on a $0.10 part if you don't.
And look at TPIC6B595s too.
The outputs only pull down, but can each switch more than 35 V and 150 mA.
Delta_G:
If you go to the right place they're cheap as hell. Get a handful. You'll find more uses for them. And it's a real pain paying $5 shipping on a $0.10 part if you don't.
Sweet I just ordered 20 of them from eBay free shipping.... of course I'll wait a fair amount of time for the delivery but at that price 1.53 for 20 of them... I'll take it