Ask HN: What Are You Working On? (June 2025)

I've been working on Splice CAD – an in-browser cable-harness designer.

Building cables for multiple personal and professional projects, I was frustrated by having to cobble together harness diagrams in Illustrator or Visio, cut snippets from from PDFs for connector outlines, map pin-outs, wire specs, cable constructions, mating terminals, and manually updating an Excel BOM.

Splice gives you:

An SVG canvas to drag-and-drop any connector or cable from your library to quickly route and bundle wires. Assign signal names to wires or cable cores.

Complete part data Connector outlines, pin-outs, terminal selections (by connector family & AWG), cable core colors & strand counts, wire AWG/color.

Automated BOM & exports parts-ready diagrams, wiring drawings, and a clean BOM in SVG, PNG, or PDF.

Connector & Cable Creators. Connectors or cables not in the existing library can be added with an optional outline and full specs (manufacturer, MPN, series, pitch, positions, IP-rating, operating temp, etc.), then publish privately or share publicly.

Demos & tutorials: Harness Builder → https://www.youtube.com/watch?v=JfQVB_iTD1I

Connector Creator → https://www.youtube.com/watch?v=zqDsCROhpy8

Cable Creator → https://www.youtube.com/watch?v=GFdQaXQxKzU

Full tutorials → https://splice-cad.com/#/tutorial/

No signup required to try—just jump in and start laying out your harness: https://splice-cad.com/#/harness. If you want to save, sign up with Google or email/password.

Continuing to make some additions and changes to ease use and improve the appearance of the harness design:

[1] Added many standard DSub, M8/M12, and USB connector outlines/pin arrangements to aid in the creation of connectors not currently in the library

[2] In concert with the addition of more connector outlines, added a Magic Button on the Connector and Cable Creator pages that pulls all fields for an entered MPN from Digikey or Mouser. Now, you can just enter your part number (like CDM806-04A-MP-F011-67 for this CUI connector, https://www.digikey.com/en/products/detail/same-sky-formerly...) and the fields will populate automatically. If a standard outline is recognized, you have the option to load the outline and pin arrangement too. For cables, this will pull the core count and other cable properties.

[3] The Harness Builder now features a grid and snap-to functionality to align items. You can also share a link (ie, https://splice-cad.com/#/shared/lgcy2htze9zlqs4igdgycfncy98f...) to a harness design that a collaborator can view or clone/edit).