Fable 5 designs a working PCB from a one-sentence prompt

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Fable 5 designs a working PCB from a one-sentence prompt

A hobbyist asked Fable 5 to design an RP2350 dev board for an E-ink display, then ordered it from JLCPCB without touching the files. The result: a functional 4-layer board for €26 each. Fable nailed component selection and routing, though it picked wrong packages for the flash and transistor, and used Freerouting, which stalled at 69 connections.

I love how I was able to just describe the board I want in plain English, send the files overseas and then receive a fully functional board without knowing any proper PCB design knowledge.
  1. XRG

    As someone who does both hardware design (mostly high precision analog electronics) and software engineering, the difference between both fields in AI capability is striking. Models like Fable and Astra can provide lots of interesting insights into the design of specialty electronics when prompted correctly. Yet they can hardly put that knowledge to work if instructed to generate a schematic or lay out a PCB.

    Of course, for readers here with a solid grasp on how LLM's operate it's not exactly surprising. Still, I feel this is exactly the kind of thing that drives home that the way we reason about (general) intelligence does not map cleanly to LLM operation, no matter how advanced the current models are.

  2. seveibar

    AI is exceptionally good at RP2040/RP2350/ESP32-based boards, we've ordered ~15 unique designs, mostly RP2040-based that were designed and autorouted with AI using tscircuit and usually OpenAI models.

    Currently the major mistakes that AI makes: 1) Improperly rotated connectors (backwards USB port) 2) Endless routing loops for complex boards 3) Really huge/unreadable single page schematics

    I'm extremely bullish on AI for PCB design, but there is a huge, huge tooling gap. We basically need to soup up all our collective design rule checks so that AI can work in corrective loops. It needs to check for things like "opamp schematic layout conventional" and "trace width closely matches reference design for chip". One thing that makes me super excited is supply-chain resiliency when chip/subcircuit-swapping becomes super easy

  3. sottol

    I'm still waiting on my order of 15 PCBs done with Sol - a mini-BT-keyboard that I hope will be comparable to the Psion 5 / Gemini PDA ones, using Kailh PG1316S switches. I still need to design and manufacture a housing (I do have a lot of hobbyist experience with this though), but the idea is to have a magsafe-connectable keyboard I can clip onto my Pixel and make use of the new Linux subsystem (or Termux) and do some productive stuff on the go. It's just been manufactured by JLC but not shipped yet. Funny enough, production itself was ~$70, then $80 for shipping, taxes and fees (tarriffs?).

    Instead of directly generating Kicad, I chose to let it write "generators" in Python that output Kicad (S-Exps!) pcb and project - with mixed results - but I can generate a version with/without per-key Neopixels and customize certain parts of the board, including debug-stuff. I also _think_ this makes it easier to resume working on this in new sessions but not sure. Otoh, I never actually looked at the Python (vibed...) so it's still a lot of hard-coding.

    I also landed on and used KicadRoutingTools after trying FreeRouting, combined with some minimal "auto-placing" code for larger ICs and such that are placed with certain constraints. My routing runs are way slower though - on the order of minutes.

    I always wanted to try atopile - that might be a good match for AI/PCB work. The only thing that really held me back was the lack of routing.

  4. the__alchemist

    Hey - I ordered a board yesterday. I used Opus 5, Astra, and Sol at points to QC the board, and offer power routing advice. (The MCU is a brand new one, and poorly documented unless they send you an NDA and the full docs).

    Those models were not capable of even schematic editing or building. (I didn't bother with routing or placement). They made gross errors all over the schematic; changed the known-working parts and net routing I'd copy+pasted from previous boards, changed I2C to SPI for no reason, and generally produced an unusable, unreadable result. Overlapping symbols and labels etc.

  5. muglug

    Bought to us by Fable 5 and the more-experienced colleague who foresaw potential issues.

  6. brotchie

    This LED star PCB was 95% generated by Codex: https://www.youtube.com/shorts/8a52LjovhcE

    Was non-trivial (e.g. days and days of cumulative work) but worked with Codex to build up a parametric generator where I could adjust the star size, number of rings, leds per ring. It did all the LED-to-LED routing, panel layout with mouse bites, placed decoupling caps. At the time Codex wasn't as good at spatial reasoning, I expect that Astra would do this much faster.

    4 x layer PCB with GND and 5V inner layers. WS2816B LEDs (not available in strips yet). 3D printed a frame so that two stars could be opposite each other (video shows only one side). ESP32 S3 on a 3.3v to 5v shifter board sandwiched in between. ESP32 wifi antenna pokes through and sits on a keep out section. Received control signals from a central controller via ESP Now.

  7. Rival67

    I've been working on several PCB projects, and agents are very helpful for automating many parts of the workflow. They're excellent for schematics. Complex routing, though, is still a human's job for now; I've watched Freerouting fall on its face many times. If you're doing six-layer high-speed DDR routing, AI won't solve that for you today.

    However checkout EDA tools

    https://github.com/l3wi/claude-eda/

    https://github.com/drandyhaas/KiCadRoutingTools

  8. ZuLuuuuuu

    In our company, we are doing high speed PCB designs with FPGAs, memories, ADCs, DACs etc. We are not yet using AI much in our PCB design workflow because our designs seem to be too complex for the AI solutions we have tried. Are there any areas where people are successfully incorporating AI to their PCB design workflow, even with complex, high speed designs? Schematic/layout review? Routing? Footprint creation?

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2026-09-17