Vibe-Coding a PCB – surprisingly good

IDK, modeling, constraints, simulations and stochastic processes seem like a match made in heaven.

It's like how pairing a coding agent that can run unit tests and iterate is way more powerful than code gen alone.

While the author has very different aims and intended scope, I have been able to leverage both "traditional" (lol) LLMs and Cursor to design and program for novel device design. The results have been pretty incredible to me, and all of the salty comments about the utility of AI to assist with electronics are fully missing the mark.

It's been my direct and many-times-repeated experience that o3 is an incredible electronics engineering wingman, so long as you follow good LLM hygiene; basically, verify all important assumptions, actually read the datasheets, err on the side of too much detail.

The time spent crafting prompts is the time I would spend planning and iterating on designs anyhow. Unlike a human, I don't have to pay them by the hour to patiently explain the nuances of different diodes or suggest alternative parts. o3 is remarkably good at rapidly grokking intent and making suggestions that have unblocked me.

For the camp of armchair quarterbacks on this site who demand specific "evidence" that we're not all just hallucinating the value of these tools, here are two things that happened just this week:

I was blowing my brains out troubleshooting a touch IC, IS31SE5117A. No matter how good my reflow or how many units I tried, I could not bring up an I2C connection. Based only on the fact that Cref refused to rise above ~0.1V when it's supposed to be about 0.7V, it suggested that it seemed likely that I had units from a batch that had no firmware. After going back and forth with their lead engineer for a week, I ordered a few IS32SE5117A - automotive/medical spec, same chip - and it worked immediately, prompting a product recall.

I'd managed to implement galvanic isolation on my USB connection to eliminate audio hum, but it turns out that touching a capacitive pad on a device that has no outside ground connection means that static has nowhere to go but to reboot the microcontroller. I'd been chasing my tail on this for a while, but o3 suggested that instead of isolating my whole device, I could just isolate my MIDI OUT circuit. This is one of those facepalm moments that only seems obvious in hindsight. I told my partner that abandoning weeks of effort was first very hard, and then very easy.

Finally, last night I had Cursor generate both sides of an SPI connection between two ESP32-S3s, something I had never done before. I obviously could have figured it out in 2020, but it would have taken me 1-2 weeks and it wouldn't be nearly as clean or cover as many edge cases.

My hottest take is that LLMs are already (far?) more valuable for engineering tasks than coding. That's kind of unfair because by definition, these tasks involve coding. The speed at which I've been able to iterate has been kind of nuts.

Also: any claims that people who tackle complex domains from a cold start somehow aren't learning fundamentals from a mentor with infinite patience and awareness of every part and circuit design pattern are simply wrong.

I'm not saying you're wrong, or that I know better.

Yet I have to say that if you are correct, the term is no different than eating tide pods or dry swallowing cinnamon. Why tf would anyone impose such an absurd artificial constraint on themselves, on the tool, or on whatever they are trying to build? Good faith question, I promise.

Constructing detailed prompts to ultimately pair program impressive, complex outcomes is what I assumed vibe coding was. After 35 years of not being able to tell a computer to write the code for me, even getting an 80% coherent first pass of a sophisticated refactor was already radical enough.

If that's what vibe coding is, then nobody should be using that term because it might be the perfect example of "just because you can, doesn't mean you should".

> Yet I have to say that if you are correct, the term is no different than eating tide pods or dry swallowing cinnamon. Why tf would anyone impose such an absurd artificial constraint on themselves, on the tool, or on whatever they are trying to build? Good faith question, I promise.

IDK! I don't think Vibe Coding, with the definition that I understand, is a good idea.

But the term comes from here: https://x.com/karpathy/status/1886192184808149383

And the key parts are:

> "forget that the code even exists"

> "I don't read the diffs anymore"

I myself am unclear on what the "vibes" that one is giving into actually are. But terms should have meanings and my understanding from reading the original tweet is that "Vibe Coding" means something distinct from "coding using some AI to help".

> Sure, but the utility of that for PCB design wasn't demonstrated in the article.

Forget about the article. Try it yourself. Set aside 5 or 10 minutes to ask any LLM of your choice to generate a LLM prompt to generate PCBs. Iterate over your prompt before using it to generate your PCB. See the result for yourself.