Really Green Newbie

OK - I haven't done this stuff is SO long. I know almost NOTHING. Sorry :-/

I will be interfacing the Arduino Diecimila to another IC. It uses TTL level input. So do I need pull-up or pull-down resistors in the middle of that? Or can I just plugin the Digital IO lines directly in to my second chip?

Thanks all,
Brandon

The Arduino works with 0V for low, 5V for high, so it is at TTL levels. The IO lines are able to sink and source 40mA of current, which should be plenty to connect to a TTL chip without drivers.

Thanks!

Also - I am designing an application that is meant to be onboard a boat. Any reason why I should not just plug directly in to the 12 volt battery on the boat? The Arduino says it works on 12 volt - but the batteries in cars/boats often end up a smidge higher than that

Check the specs for the regulator on Arduino compared to what the boat battery might do. Also, you need to consider how "noisy" the electrical system on the boat is. It could cause a lot of trouble or blow the Arduino (I'm not at all familiar with how bad the problem can be).

Also, you need to consider how "noisy" the electrical system on the boat is. It could cause a lot of trouble or blow the Arduino (I'm not at all familiar with how bad the problem can be).

In RC, you never have your controller running off your main batteries for two reasons. One is noise (as above) and the other is drain.
Stall current could be rather high on RC motors and will cause large voltage dips. This could cause the Arduino to reset. Also, when you main battery dies, you still want "the system" alive and kicking on other batteries.

My 10 cents worth...

Cheers,
Crispin