This tour will take you through all the major steps from drawing a schematic over routing the board to finally generating your CAM data – and beyond!
The Control Panel
The Control Panel gives an overview about EAGLE Libraries, User Language Programs, CAM Jobs Design Rule Files and Projects. Basic configuration can be made from here.
* Libraries and User Language Programs Overview
* Create and Manage projects
Drawing The Schematic
A schematic can be drawn on several sheets. The basic steps in drawing a schematic are:
* Place the Symbols
* Draw buses
* Connect with Nets
* Move and Edit
The Hierarchical Schematic
For more complex schematics a hierarchical structure may help in make it better readable and understandable. Typical steps:
* Define a Module
* Place Module-Instances
* Set Ports and connect them with Nets
Checking The Schematic
The Electrical Rule Check points out errors in the schematic, like
* Nets without connections
* Conflicting outputs
* Open input pins and ports
Creating The Board
Creating the board from a schematic is one of the easiest tasks with EAGLE. Click the Board icon and EAGLE opens a new window with all the parts arranged next to a default board outline. All the nets from the schematic are shown as air wires.
Placing The Parts
The Move command allows you to pick up each part and move it to its desired position. You can also move entire groups of parts. The right mouse button rotates the current part or group. The middle mouse button mirrors a part onto the bottom side of the board. The Ratsnest command recalculates the air wires.
Routing the Signals
Manual routing is done with the Route command. Simply pick up an air wire, adjust the angle with the right mouse button, and select the layer with the center button. Vias will be added automatically as needed.
Routing With The Follow-Me Router
The Route command has a special option that uses our Follow-me Router for manual routing. The signal wire will follow the mouse cursor position and takes automatically care of all Design Rules: A convenient way for error-free manual routing (Autorouter module required).
Differential Pairs and Length Balancing
Two signals can be routed simultaneously. Clearance and width are defined via net classes. A final length balancing with the MEANDER command provides identical signal lengths.
At any time you can
* Move, Rotate and Mirror objects
* Change parameters
* Split wires etc.
And you never have to worry about messing up things because you have the most powerful Undo/Redo function at hand which undoes 100% of every editing command.
EAGLE comes with a Ripup&Retry Autorouter with an optional TopRouter variant which is user configurable through cost factors. It supports multiple-core processors and can calculate a number of routing jobs with different settings for the board. After processing the routing variants you evaluate the results and choose the best one for you.
Checking The Board
The Design Rule Check (DRC) points out errors like
* Minimum distance violations
* Drill Size Violations
* Minimum width violations
Errors are displayed graphically and can be easily accessed through the Error command’s popup list.
Fine Tuning The Project
Designing a PCB is never a true straight forward job. For example, you might want to add an additional capacitor to your board. With EAGLE’s online Forward- and Back annotation you can simply select the schematic window, add the capacitor and connect it. Simultaneously, you can see the part and signals being added to the board window.
And it is just as easy to swap pins and gates, change names or draw additional connections. And as always, any editing function you use can be 100% undone thanks to EAGLE’s outstanding Undo/Redo function.
Creating copper areas is done with the Polygon command. It allows you to draw the outlines of an area and assign it to a specific signal. The Ratsnest command then calculates the exact shape of the copper area. Unlike other programs which implement copper pouring by subtracting layers from each other, EAGLE actually calculates the entire shape of the area. It therefore can detect orphaned areas (which are not connected to the signal, like in the lower right corner of the example).
Producing CAM data
The CAM Processor allows you to create the data you need to manufacture your PCB. It can produce data for drill stations, photo plotters, Postscript machines and pen plotters. You can easily adapt the CAM Processor to your specific output device because all devices are defined in a user editable device definitions file.
The EAGLE User Language gives you full access to the internal data structures. With its C-like language you can write your own programs that access your design files and create virtually any output you might need. Whether you want to create a simple customized part list or go all the way to connecting a specific simulation program – EAGLE’s User Language has the potential to do it!
Defining Library Parts
Although EAGLE comes with a full set of part libraries, sooner or later you will have to define your own library parts.
With the fully integrated part editor this is an easy task, you simply
* draw the Symbols
* draw the Package
* put it all together in a Device