Noob Eagle CAD Questions

[donggyu]

I think I might want to start designing my own pcb boards, and I have a some questions:

-Why do you people design pcbs and send it to a fabhouse where they make it for you? What does the fabhouse do?

-What is the arrow symbol in the green/red schematic? Why are the grounds often not connected to anything?

Thanks!

-Donggyu

[Ro-Bot-X]

You should read the SparkFun Beginning Embeded Electronics tutorials:
https://www.sparkfun.com/commerce/tutorials.php

[donggyu]

Thanks! My question relating to the arrow symbol and the fabhouse is still unanswered though. Can you please explain it to me?

[rbtying]

Arrows are usually GND, as the CAD program will connect the GND and VCC for you.

[donggyu]

So the arrows AND the traditional ground sign is GND? Confusing..

[rbtying]

Which arrows are you talking about?  Normally the one that seems to point off into nowhere ( ->) is GND, as the CAD program connects those.  I'm not really aware of other arrows.

[Razor Concepts]

From my experience arrows typically face upwards and indicate VCC

[galannthegreat]

Here's a picture that shows some of what you mean. (there are other symbols, but these are some of the most commonly used, though I am familiar with with the up arrow as Vcc, don't know why it isn't here)

[donggyu]

Oh ok. What is the difference between a signal ground and a power ground?

[Ro-Bot-X]

Thanks! My question relating to the arrow symbol and the fabhouse is still unanswered though. Can you please explain it to me?

The other members answered tour arrow question.

We send the boards to the fabhouse because they can fabricate them cheap. For instance, 10 boards up to 5cm x 5cm are $20 to make. If you can do one board in one hour at the quality of a fabhouse for $20 then do it by all means. I would pay myself to do it at least $10 per hour, as it will not have plated holes and solder mask. To make a board you need tools, like a drill press capable to hold and drill with tiny bits, a laser printer for the toner transfer, chemicals to etch the board, then again toner transfer for a silk screen. Not worth it in my  opinion. If you only want one board, go to BatchPCB at SparkFun and get it for about $15.