With printed circuit board (PCB) and schematic design software you can create design files that will allow a PCB manufacturer to turn your design into an actual circuit board. PCB layout software packages are generally expensive pieces of software meant for corporate use. Eagle, however, is a powerful design package that is available free for non-profit use. The freeware version of Eagle limits the size of the board you can design, but has no other limitations. If you need to make a larger circuit board, you can upgrade to a more powerful non-profit version for a fraction of the cost of the corporate edition.
Instructions
1 Click "Start," "All Programs," "Eagle," and click "File," "New," and then "Project." A new project folder will appear under "Projects" in the "Control Panel" window. Type a name for your project, and press the "Enter" key.
2 Click "User Interface" under the "Options" menu in the "Control Panel" window, and click to check the "Always Use Vector Font" option. This way, the text you print on the schematic will be in a font that can be silk-screened onto a circuit board.
3 Right click on your new project folder; hold the cursor over "New," and then click "Schematic."
4 Click the "Add a Part" button on the left-hand toolbar to add parts to your board. Most of the buttons on the toolbar are self-explanatory, such as "Rotate an Object" and "Delete." When you hover the mouse over a button a tool tip appears saying what it does. When you click the "Add" button, the "Library" window appears.
5 Click the part you want to add from the "Library" window. Eagle PCB comes with a huge library of parts. Most components are subdivided by manufacturer, and generic components like resistors and capacitors are listed in their own categories. Click "Okay" to return to the schematic editor. The mouse cursor turns into the schematic symbol for the part you've chosen. Click anywhere on the schematic to add the part.
6 Click the "Net" tool button, and then click on the schematic to start drawing a wire. The wire follows the mouse pointer and automatically snaps to the grid as you draw, helping you accurately connect components. Click on the schematic again to change direction, and double-click to finish a wire.
7 Draw a short wire sticking out of a component, leading nowhere. Do the same for every component you want to connect it to. Click the "Name" tool, and then click on each short wire you placed and type in a name. Every wire with the same net name will be connected when you transfer the schematic to the layout editor. Using net names helps you connect components without drawing a tangle of wires everywhere.
8 Click the "Copy" tool, the object, and then click again on the schematic where you want to place a copy. Click the "Group" button, and then drag a box around the group you want to copy to copy a group of objects. Click "Cut," and then click the group. The whole group is highlighted. Click "Paste," and then click anywhere on the schematic to add a copy of the group.
9 Click the "Board" button at the top of the schematic editor to transfer your schematic to the circuit board layout editor.
10 Click "View" and then "Grid" to bring up the "Grid options" window. Turn on the "Display" option by clicking the "On" radio button. This will make the grid visible in the board editor. Set the grid size to 0.1 inch.
11 Use the controls in the tool bar to arrange your circuit on the board. The board editor controls are almost identical to the controls in the schematic editor, with the same buttons for "Move," and "Copy," for example. However, instead of drawing wires, you route circuit traces using the "Route" tool, which works just like drawing wires in the schematic editor. The black rectangle drawn on the schematic indicates the edges of the board. Use the "Move" tool to drag the edges of the board and re-size it as needed.
12 Click on "File," and then "CAM Processor" to export your layout to a format that can be used to manufacture a circuit board. Different manufacturers may have different file requirements, so contact your board manufacturer about what settings you'll need to use in the CAM processor.
