mattallen37 wrote:On a battery run line, probably no caps would be REQUIRED, but I would still use at least one.
Yes. The board has them, but as Andy said, they are probably way too strong. I would remove them and add normal resistors (not surface mount) for pullups. The NXT sensors use 82k, but I have used 100k, and NXTreme has used 10k, on a 4.nV line, with no problems.
Actually, most if not all LDO regulators are switching regulators which means that they introduce spikes or noise into your power rails. You
have to include caps otherwise the operation of your circuit will be spotty at best. You normally only need one or two ceramic, aluminum electrolytic or tantalum capacitors on the output but it isn't a bad idea to also include a ~100uF electrolytic on the input as well if your design/robot has any motors or noisy sensors (Sharp distance sensors come to mind) in it. You can always find the specifics about the required caps in the datasheet.
I personally use the LP2950 LDO regulator
* but that's just because it was cheap (~$1 US for the 100 mA through hole version) and it's what Digikey had.
* Cue heated discussion of the ups and downs of certain regulators. I'm sure we all have our favorites.
-EDIT- Darn, maybe I should build the "edit" button into my mouse. Yes, I have had success using 10K pullups but like Matt, I think 4.7K might be a bit much. You don't need any special equipment to remove them, just a soldering iron and some solder. Stick a big blob of solder on the tip of your iron, touch it to the part you intend to remove, let it heat for a while and just swipe it off. Just don't get rid of the caps instead
. You can clean the board a bit with some solder wick and hand cleaner that has alcohol in it.
You can also buy SMT resistors for a couple cents from Digikey or Mouser. Digikey has a shipping option that is only ~$2 US, your whole order would probably come out to less than $5. And yes, you can solder them
.