Electronics Design Automation - KiCad Schematic Capture

BME254L - Spring 2026

Author
Affiliation

Dr. Mark Palmeri, M.D., Ph.D.

Duke University

Published

January 8, 2026

Electronics Design Automation: Schematic Capture

Schematic Capture

UI/UX

Creating a Schematic

KiCad Documentation: Schematic Editing Operations

  • Create a New Project, which creates a schematic file.
Warning

DO NOT CHANGE THE GRID SPACING!!

  • Setup Page Settings..., using semantic versionin for Revision.

  • Configure Schematic Setup..., including Project:Net Classes.

  • Place component / part (Place Symbol) using default library. If component doesn’t exist, then you either need to:

  • Annotate components (give each component a unique label).
Note

This is now done automatically in KiCad 8.x, but you may want to manually override some of the annotation defaults.

  • Assign component values

  • Label nets with meaningful names

    • Nets are like nodes; common voltage connections.

    • Use net labels to avoid connection chaos.

In-Class Exercise: Part I

Let’s create a simple voltage divider circuit…

Power Ports

  • Power ports, including ground references, are also global net labels.

  • Component pins can be explicitly designated power in/out (in contrast to signal).

  • Power, ideally, cascades top-to-bottom (+ \(\rightarrow\) GND [\(\rightarrow\) -]) on the schematic.

In-Class Exercise: Part II

Let’s add power ports…

Electrical Rules Check (ERC)

  • Check the validity of the schematic

  • Common error message:

“Input Power pin not driven by any Output Power pins”

  • KiCad checks to make sure that power can “drive” components that demand that input.

  • You can explicitly indicate this in the schematic using the PWR_FLAG symbol attached to the net in question.

  • Might need to re-map pin types (Properties:Edit Symbol:Pin Table).

Best Practices

  • Signal, ideally, flows left-to-right (input \(\rightarrow\) output).

  • Outline and label functional blocks. Use Heirarchical Sheets to organize more clearly-defined sub-circuits.

  • Can include non-electrical items, like Mounting Holes.

  • Add Test Pins/Pads to nets you will want to verify during testing.

    • Power nets

    • Signal I/O

  • Use No-Connection flags for pins that are intentionally not connected to other components.

schematic_annotated

Schematic Components Not on the PCB

If a component will not exist on the PCB (e.g., a power switch, a control knob):

  • Be sure to exclude it from the board (Properties \(\rightarrow\) General \(\rightarrow\) Exclude from Board).

  • Represent the Connectors or Terminal Blocks on th schematic that will be used to connect the component to the PCB by wires.

In-Class Exercise: Part III

Modify your circuit to use a 9 V battert that will be connected to the PCB using a 2-pin connector.

Heirarchecal Sheets

  • Circuits can get very complicated very quickly; quickly separated from functional signal flow.

  • Can organize functional sub-circuits into sheets (similar to writing functions in software development).

  • Sheets require explicit types of “pins” to allow signals to communicate between sheets.

  • Power ports are global and do not need to be explicitly connects.

Example Project Schematic

Bill of Materials (BOM)

  • All of the components in the schematic can be populated into a Bill of Materials.

  • Industry-standard ECAD packages will be automatically linked to online part catalogs to order.

  • Components excluded from the board are still included in the BOM, unless explicitly excluded from the BOM (Properties).

Troubleshooting

  • Certain video cards will not work well with the PCB tool. In that case, disable the Accelerated toolset and choose the Fallback graphics toolset.

  • On Macs, your part / footprint / model libraries might not be detected automatically after installation. You might need to manually point Kicad at them in a path similar to: Macintosh/Library/Application Support/kicad/templates/sym-lib-table/.

Resources