scott wrote:

> But in the end you're doing things backwards, learn the basics *first*, 
> it will make your life so much easier, and you won't get stuck at every 
> point when things don't work as expected.  You will be able to answer 
> your own questions if you have the knowledge of how basic electronic 
> circuits work.

Funny, I thought I *already* had a basic knowledge of how circuits work...

I guess what's throwing me is this new "logic low = negative" thing. I'm 
used to thinking of logic low as "nothing connected here". If you were 
making a bunch of logic out of switches with either connect or don't 
connect a wire to the positive rail, everything would be quite a bit 
simpler. (E.g., connecting the output of two gates together couldn't 
possibly create a short-circuit condition, since each output is 
connected to the same battery terminal or to nothing at all.)

I guess I'm still trying to get my head around all the consequences of 
that. For one thing, it looks like every single [external] input and 
output is going to end up needing a resistor on it. Yay. :-/

> For example the next thing will be relays to control things that need 
> higher power or voltage, you're going to connect one of your outputs to 
> a relay coil and then wonder why it's not working, and then complain 
> that the relay is destroying all your ICs :-)

Uh, no, even I'm not crazy enough to want to do that. :-P

1. I'm turning LEDs on and off. What the hell do I need relays for?

2. Relays are comparatively expensive.

3. Relays presumably use about 100x the current that an IC can supply.

4. PROFIT!

5. Relays move vastly slower than even the slowest electronic logic 
gate. Why bother?

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