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I'm building a 3D printer and I'm a little over my head. Right now I'm trying to make sure most of my components play nice with each other with some simple code and only one motor.  Here's my set-up:

I have a seeeduino mega. More on the pinouts later. It's being powered via USB and I don't know if that's okay.

 

How many of you guys garden?

I'm thinking of using a bunch of LEDs for a secret project. Here's the catch: they have to be able 'flicker' too quickly for the human eye to see. 

How quickly do LEDs go from off to on? Is there any delay - do they have to 'warm up' like incandescent light bulbs? Realize a half second delay is way too much for the project I have in mind. Are there any fast-acting LEDs out there? Or is it virtually instant, only hindered by the speed of the electrons through the wire?

Some of you may remember way back when I had tons of problems with programming my picaxe. Well, they're back with a vengeance.

I recently got a breadboard and decided to try programming my Picaxe-08M with it. I followed this image:

Dagu is great and has really nice prices, but the shipping to the States is killer. I really want some of those little servos! I think if we got enough people, though, we could even it out. Here's how it would work:

 

I'm pretty bad with electronics... I'm more about putting things together I guess. But I need a little help:

I don't understand how a power source (battery) has amps. Isn't current (amps) a function of voltage and resistance through ohm's law? Is it possible to blow something with too many amps like it is with volts?

While we're at it, what happens when you put a voltmeter behind a resistor? Where does that number come from?

I'm working on a project (shh, don't tell) and I need a little coil of nichrome wire. Some research tells me that a big roll can be bought for like $15 USD but I honestly don't need that much. It's the heating element used in those car cigarette lighters (the kind you plug into the socket...you know what I mean) and (i think) toasters. If anyone has a roll laying around or an old toaster or lighter, would you mind mailing me a little bit, like three or four inches? I can give you a dollar or so or stamps or something, and I have some salvaged parts I could trade you.

So, before, I got the error: No hardware on com 1.

I have tried the hard reset, it starts downloading, and I get :

"Download For Picaxe on com1 failed

Error:

Verification error - 0x00 transmitted but nothing received at byte 0"

occasionally, it is "...nothing received at byte 37" 

I get this with both my 14m and 08m. What am I doing wrong?

 

Does the picaxe programming circuit need to be in place while a picaxe is running? In other words, can I use a breadboard and picaxe breadboard adapter ( http://www.sparkfun.com/commerce/product_info.php?products_id=8331 ) to program it and then put the chip on a pcb separate from the breadboard?