Learning to make electronic boards with EagleCAD
Overview
Familiarize myself with Eagle.
You can download Eagle at:
CadSoft Eagle
Eagle has two parts we will work with.
- Drawing an electronic schematic.
- Laying out the circuit board traces.
Todo: Familiarize yourself with circuit symbols.
Learning EagleCad
EagleCad is both intuitive but also takes time to learn. The parts library speeds things up. It will take practice
to visualize the setups so that you can have cleaner wiring of boards.
The first thing I did was try to reproduce the tinyISP boards from Week 4. The large number of routes made this a
difficult first learning experience. See the slideshow. Click for closeups.
We have imported the
fab library so that we can add elements that are on hand.
LEARN:
Use the Add Command under EDIT menu.
FEATURES:
ATTNY44 Chip in EagleCAD
LEARN:
Continue to find elements and add to the schematic.
FEATURES:
Adding a junction
LEARN:
Elements need to be connected.
Use the NET tool to properly connect elements.
FEATURES:
Our first wire.
COMMENT:
Wiring is easy but even a few elements can get messy.
Hopefully practice helps with the initial layout.
FEATURES:
Adding More Wires
LEARN:
Rotating elements is essential for untangling messy boards.
(Use the rotation tool.)
The Move Tool and Delete Tool got used often.
FEATURES:
Lots of wires.l
LEARN:
Delete and re-route wires often.
The cleaner the board is now, the easier it will be to work with later.
FEATURES:
Wiring
LEARN:
Delete and re-route wires often.
The cleaner the board is now, the easier it will be to work with later.
FEATURES:
Wiring
LEARN:
You can add a Frame from the Add menu as well.
This will allow you to add a description.
FEATURES:
Wiring
LEARN:
Converting to a board from schematic takes time.
Switch to Board from File menu.
FEATURES:
Wiring
LEARN:
The first pieces need to be placed on the board.
You are trying to untangle the connections as much as possible.
FEATURES:
Wiring
LEARN:
Routing the traces is difficult, but at least you do not have to worry about where things go.
The challenge is getting the paths correct.
FEATURES:
Wiring
LEARN:
The computer does a decent job of routing. Start
by usingthe autoroute.
FEATURES:
Wiring
LEARN:
Routing paths is hard. You are trying to keep paths from crossing that
are not suppose to. Use vias to route to the back side of the board.
FEATURES:
Wiring
COMMENT:
This will take time to figure out.
FEATURES:
Wiring
Bootstrap Carousel
Making the Echo Hello World Board
I am glad I have already gotten some experience with Eagle before doing my homework. The assignment is to
make the Echo Hello World Board.
Looked in the fab library for the ATTNY44 chip. Inserted into circuit schematic.
Add the header pins for FTDI(right) and ISP, in system programmer(bottom).
Add 10K resistor. It is the pull up resistor. This stablizes the potential on the RST to be high.
The pin is active when at a low potential.
Add capacitor(1 microFarad).This acts as a filter.
Wire in the headers.
Wire in all the other elements.
Add an led and limiting resistor.
Add a switch.
Route the traces.
Fix problems. Retry. Fix Problems.....
Make the board.
Recap
The goal behind this should be to design and make the board. An elegant board should be possible. I am not sure if my
board meets that standard. It takes some experience to layout the board to avoid crossing routes. I have many vias as a
result. Eagle took time to work. With the biggest time taken to find where everything is and then to see the patterns.