Introduction to Circuit Design Software
Last lesson you learned to read schematics; now you will create your own using circuit design software and take a simple circuit all the way to a manufacturable PCB file. You will build an LED, resistor, and battery schematic in a browser-based tool, convert it to a PCB, let the auto-router lay the traces, and export the Gerber file a factory needs to make your board.
What circuit design software is
Circuit design software lets you create professional schematics and PCB layouts for your projects. Hobbyists and professionals use the same kind of tool to design, check, and prepare circuits for manufacturing. It matters for two reasons: it reduces errors by checking your work as you go, and it produces the exact file formats a PCB factory requires. In fact, exporting the right file is the only way a manufacturer will accept your design at all.
Local versus browser-based tools
Some tools install on your machine, like KiCad, and some run in a browser, like EasyEDA. This course uses the browser-based option so it works on any computer, including a Chromebook. The good news is that the concepts transfer: almost all of these tools work the same way, and the end goal, getting your design into a Gerber file for a manufacturer, is universal. Learn one and you can pick up the others quickly.
Where PCB design sits in the process
You have now seen the full path a circuit takes. First you prototype on a breadboard, where parts push in and out. Then you move to a soldered perfboard, a semi-permanent version. Finally you design a PCB in software and send it to a manufacturer for a clean, machine-made board. Each step is more permanent and more professional than the last, and the same simple blinking-LED idea can travel through all three.
The schematic editor interface
A schematic editor has three main areas. The toolbar across the top holds the functions for drawing wires, placing components, and labeling, much like the toolbar in a word processor. The component library lists ready-made symbols for resistors, LEDs, switches, displays, and more, and you can search for or import additional parts. The large central workspace is where you build your schematic. You place symbols from the library, position them, and connect them with the wiring tool.
From schematic to Gerber file
Once your schematic is drawn, the tool converts it into a PCB layout. Before it will finish, it runs a design rule check that catches problems such as incomplete connections, where two parts look joined but are not actually wired in the design. Rather than fixing every trace by hand, you use the auto-router, which lays the copper connections for you and turns thin placeholder lines into real, routed traces. When the check passes, you generate the Gerber file, a zip containing everything a factory needs to fabricate the board, and you choose options like board color and quantity. That file is what you send to a manufacturer.
AI-assisted design, used wisely
Newer tools such as Flux use AI to help generate a design from a plain-language description. These can speed you up, but the order matters: learn the fundamentals first, then use AI to work faster. Understanding why a circuit is built the way it is means you can catch when an automated tool gets it wrong. Once you have that understanding, reaching for AI is not cheating; it is being resourceful with the tools available.
Working through it
Open the tool and start a project. Go to the browser-based editor, create an account to save your work, and start a new project named for this lesson. This opens the schematic workspace.
Place the three components. From the library, add a resistor and an LED. For the battery, use the library search to find a standard 9V battery and apply it into your circuit. These three symbols are all this design needs.
Orient for correct polarity. Rotate the battery so its positive terminal lines up to feed the resistor and the LED's positive leg. The battery here plays the role the board played before: it simply supplies power to light the LED.
Wire the loop. Use the wiring tool to connect the battery's positive terminal through the resistor, into the LED's positive leg, out its negative leg, and back to the battery's negative terminal. That completes a working power-on-LED circuit.
Convert to a PCB and check it. Convert the schematic to a PCB layout and run the design rule check. If it reports incomplete connections, use the auto-router to lay the traces, then re-check until it passes clean.
Generate the Gerber file. With the check passing, generate the Gerber file, choose a board color and quantity, and download the zip. That file is ready to send to a PCB manufacturer.