220 Ohm resistor. But 1W, 1/2W, or 1/4W ? Help me spend $18

[larryd]

That's a great walk through. I have no idea why I was making it so complicated. I mean I hate math, but c'mon. It's just simple division? Why do they go and make it all complicated looking? I hope there isn't a ton of math in this. I know it's hard to be smart without knowing math but I can write code, and I thought that was what I would be doing. Why do I always get sidetracked like this? Just to be safe, I'll dig out a calculator.

Don't run away from things you have trouble with!



Another thing you might want to get are some 'logic level MOSFETs'
Search this site for discussions about them.
Basically they can be used with the voltage level (5volts) found on the outputs of a 5 volt UNO.

Watch these, don't get hung up on the math.
https://m.youtube.com/watch?v=Te5YYVZiOKs

https://m.youtube.com/user/OSHJunkies

https://m.youtube.com/watch?v=GrvvkYTW_0k

https://m.youtube.com/watch?v=81zNcctopBI

https://m.youtube.com/watch?v=EQtwsWJuUPs

https://m.youtube.com/watch?v=wxjerCHCEMg

What the heck, watch them all:
https://m.youtube.com/results?q=addohms&sm=3

Spend two or three days watching tutorials, but, buy some pizza and beer first.


.

[larryd]

Here are some typical circuits for inputs and outputs, print them out for reference:

[TheRealVictor]

I appreciate the help guys. It was getting ridiculous having to google every  little thing I came across.  It was becoming a really bad rabbit hole. I needed help breaking the loop 

thanks for the cool stuff. Ill get started on the vids.

Here is where I am at with my project. Is there a tutorial that will get me a bunch of leds fading in and out?
https://www.youtube.com/watch?v=7WvPTerAdEE

[TheRealVictor]

I have an idea what the diagrams are but I need to know what an external pull down is.  I'll find out. Im doing the mosfet next.

[Grumpy_Mike]

an external pull down

A resistor that is external to the processor, that is one you add, than goes from the input pin to ground. Generally a bad idea, see:-

http://www.thebox.myzen.co.uk/Tutorial/Inputs.html