FIRM — Filtered Inertial Rotational Module

This repository contains the KiCad project files for the Filtered Inertial Rotational Module (FIRM). FIRM is a high-performance inertial sensing and rotation sensing module developed for flight instrumentation and payload monitoring. The repository includes schematic symbols, PCB footprints, 3D models, and all board files necessary to review, edit and manufacture the module.

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Quick Start — open the project

1. Install KiCad (see Install & Setup below).
2. Clone the repository:

git clone https://github.com/NCSU-High-Powered-Rocketry-Club/FIRM-KiCad.git

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Install & Setup

First, install KiCad from kicad.org. We recommend using the latest stable release of KiCad for new designs.

After installation

• Open the FIRM.kicad_pro project. KiCad will use the sym-lib-table and fp-lib-table files included here if you open the board/schematic from this checkout.
• If KiCad shows missing library warnings, update the Project Library Tables or use the library manager to add the project's sym-lib-table and fp-lib-table.

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Repository structure

Root-level description (key files/folders):

• FIRM.kicad_sch — schematic
• FIRM.kicad_pcb — PCB layout
• FIRM.kicad_pro — KiCad project file that links schematics, board and library tables
• sym-lib-table — project symbol library table that makes project-local symbols available to Eeschema
• fp-lib-table — project footprint library table that makes project-local footprints available
• 3dmodels/ — 3D STEP/WRL models used with footprints
• symbols/ — human-editable symbol libraries (e.g., connectors.kicad_sym, sensors.kicad_sym)
• footprints/ — footprint libraries as .pretty directories
• FIRM_Interestlaunch/ — FIRM variant which was milled in the Makerspace.

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Library handling

We keep the project-specific libraries inside the repository so that board designs are reproducible and self-contained.

Symbols

• New symbols are added to the project's symbols directory and are registered in the project's sym-lib-table.

Footprints

• Footprints live inside .pretty folders in footprints/. Add footprints via the footprint editor and store them in an appropriate footprints/<libname>.pretty folder.

3D models

• 3D models are stored in 3dmodels/ and referenced by footprint model paths. Keep STEP files with good orientation and scale (KiCad's default is mm). We typically download the .step file from the manufacturer's website.
• If you add a footprint that references a 3D model, commit both the footprint in footprints/ and the 3D model to 3dmodels/.

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Good Practices & Design Rules

• Keep schematic symbols generic and footprints specific: do not hardcode assembly-side changes into symbols.
• Look at the existing schematic to see how we do things and try to be consistent.
• Save new libraries to the project-local tables (not global) to keep designs reproducible.
• Keep PCB footprints accurate — use accurate courtyard, 3D models, and update packaging information.
• Validate with DRC (PCB Editor > Inspect > Design Rules Checker) and ERC (Eeschema > Tools > ERC) before committing changes.
• When collaborating, include notes about part sources (Mouser/Digikey vendor links), footprints used, and any custom pad or thickness changes.

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Release & Manufacturing Checklist

Before requesting fab or assembling a board, run this checklist:

1. Run ERC (Eeschema > Tools > ERC) and fix all warnings.
2. Run DRC in PCB Editor and resolve all errors.
3. Create a BOM and confirm manufacturer part numbers and footprints match.
4. Generate Gerbers and drill files (Plot + Generate Drill Files) and inspect them in GerbView.
5. Check 3D model alignment in PCB Editor (View > 3D Viewer) to ensure components fit.
6. Tag or branch the repo in Git to preserve the release snapshot.

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License

See LICENSE at the repo root for licensing details.

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