Claude Fable 5.2 designs three electronic prototypes from one prompt: Diode built them straight from its design files, with no circuitry fixes

Claude can now design and guide the building of electronic hardware end to end from a short prompt, covering specifications, schematics, board layout and routing, a 3D-printable enclosure, firmware and a parts list. The models tested with Diode a little over a year earlier could not reliably lay out a circuit board and struggled to design components that fit together. Diode manufactured all three boards directly from Claude's design files and ran the firmware without any back-and-forth over adjustments; the speakerphone prototype still works after weeks of use, and the voice-assistant hub and virtual pet are also still in good working order.

The main gain is in reasoning through geometric problems: where components go and how copper connections are routed. Earlier models placed supporting parts too far from the chips they served or oriented connectors incorrectly. On Diode's internal PCB Gym benchmark, Fable 5.2 scored 69% versus 25% for Fable 5; on the public BenchCAD 2.1 benchmark it scored 83.5%, nearly double its predecessor Claude Fable 5.1.

During design, Claude changes course on its own rather than forcing a layout that cannot be finished. Earlier models rarely revised their own work even when a placement could never allow routing to finish, and Diode built many boards with them that were 95% complete but unusable. On the speakerphone's four-layer board it reassigned signals to different pins on two chips so tracks under the touch controls stayed on one layer without crossing; routing the voice-assistant hub, it judged the traces too tangled to trace visually and deleted and rerouted copper connections dozens of times until an arrangement worked.

It also runs design-for-manufacturing and sourcing checks itself and tracks downstream effects. Electronics design must satisfy both a factory's geometric manufacturing limits and distributors' parts availability. Checks on the voice-assistant hub flagged six solder-mask slivers as too thin, which it fixed by widening the openings without moving parts; it also judged a flagged ground-to-ground connection deliberate and harmless and ignored the flag.

The demonstrated scope is three early prototype devices—a speakerphone, a voice-assistant hub and a handheld virtual pet—manufactured by Diode from Claude's design files and assembled and tested by human engineers; they have not been through electrical validation, antenna tuning, thermal testing or certification, and were not designed for mass production.

All three devices are still prototypes: it is not yet known how they will hold up with continued use or whether they would pass commercial certifications; the model was not connected to test equipment or to the machines that make and assemble circuit boards, so Diode engineers physically built and tested the prototypes.