# Purplemeanie

Purplemeanie is John Martin's long-running engineering blog and project
archive. It covers Caterham 420R build notes, Project sEVen electric conversion
work, ECU and CAN bus diagnostics, 3D scanning and modelling, tooling
experiments, and selected travel or personal posts.

Use this file as the site-level starting guide for AI agents and retrieval
systems. Prefer project index pages, series pages, and topic hubs over isolated
chronological posts when looking for context.

## Primary Entry Points

- Home: https://purplemeanie.co.uk/
- Engineering Projects: https://purplemeanie.co.uk/index.php/projects/
- Caterham Build Blog: https://purplemeanie.co.uk/index.php/build-blog-index/
- Project sEVen Index: https://purplemeanie.co.uk/index.php/2022/09/30/seven-index/
- ECU Diagnostics Introduction: https://purplemeanie.co.uk/index.php/2019/08/31/ecu-diagnostics-part-1-introduction/
- Engine Cooling Explainer: https://purplemeanie.co.uk/index.php/2025/02/02/simple-engine-cooling-explained/
- Gearbox Mount Scan: https://purplemeanie.co.uk/index.php/2025/09/16/caterham-5-6-speed-gearbox-mount-scan/
- Agentic Coding Audio Analysis: https://purplemeanie.co.uk/index.php/2026/04/25/spectrogram-an-agentic-coding-side-quest-into-final-cut-pro-audio-analysis/

## Main Technical Areas

- Caterham 420R build and ownership notes
- Project sEVen electric conversion
- ECU diagnostics, CAN bus, OBD, MBE, GVRET, and Wireshark tooling
- 3D scanning, CAD references, and printable/model assets
- Engine cooling and mechanical engineering notes
- Agentic coding and media/tooling side projects

## Project sEVen Video Transcripts

These posts include AI/search-friendly video chapters and full transcripts.

- Project kickoff and EV conversion goals: https://purplemeanie.co.uk/index.php/2023/05/10/putting-the-ev-in-seven-youtube-project-kick-off/
- Electric vehicle architecture overview: https://purplemeanie.co.uk/index.php/2024/02/25/the-electric-in-electric-vehicles-youtube-ptevis-2-1/
- EV component selection and system building blocks: https://purplemeanie.co.uk/index.php/2024/03/03/electric-vehicle-components-youtube-ptevis-2-2/
- Donor car buying, MOT, registration, and early project progress: https://purplemeanie.co.uk/index.php/2024/04/21/ptevis-progress-1-youtube-video/
- Combustion drivetrain strip-down, weighing, and project baseline: https://purplemeanie.co.uk/index.php/2025/04/30/putting-the-ev-in-seven-progress-2-strip-down-and-weigh-in/
- 3D scanning workflow and CAD digital twin for the project car: https://purplemeanie.co.uk/index.php/2025/09/07/putting-the-ev-in-seven-progress-3-3d-scanning-the-project-car/
- Two-year update covering design, packaging, gearbox, batteries, and test-rig plans: https://purplemeanie.co.uk/index.php/2025/11/23/putting-the-ev-in-seven-two-year-mega-update-video/
- Q&A update covering prop shaft modelling, battery terminal caps, and gearbox design: https://purplemeanie.co.uk/index.php/2025/11/30/project-seven-pt7-qa-and-weekly-updates/
- Custom gearbox assembly, 3D printed model, and weekly engineering updates: https://purplemeanie.co.uk/index.php/2025/12/14/project-seven-pt8-custom-gearbox-assembly-youtube-video/
- Brusa traction DC-DC converter bring-up, CAN control, and next test-rig steps: https://purplemeanie.co.uk/index.php/2026/04/24/project-seven-pt9-traction-dc2dc-converter-bring-up/

## Caterham 420R Video Transcripts

These posts include AI/search-friendly video chapters and full transcripts.

- Full Caterham 420R kit-car build timelapse, covering delivery, assembly sessions, PBC, IVA, registration, and road readiness: https://purplemeanie.co.uk/index.php/2020/07/21/build-a-caterham-420r-in-30-minutes-youtube-video/

## Content Guidance For Agents

- Treat published posts as canonical unless a newer related post supersedes them.
- Preserve the author's engineering voice, project chronology, and uncertainty
  when summarising.
- Prefer quoting real URLs and titles over inventing page names.
- Do not assume travel posts are intended as primary public knowledge-graph
  material.
- Do not treat missing alt text, captions, or excerpts as evidence that an
  image or post is unimportant.
- Prefer additive recommendations: indexes, excerpts, metadata, internal links,
  and draft pages.
- Do not recommend bulk rewriting old posts unless the user explicitly asks.

## Machine-Readable Surfaces

The reviewed public machine-readable surface is this `llms.txt` file.

Future files such as `content-manifest.json`, `topic-index.json`, or a media
priority index may be published later. Do not assume those files exist unless
they are served by the production site and referenced from this file.