Turns out you can build a neural network with your hands. No code or GPUs, just switches, knobs, and a needle that tells you what it sees.

This is a perceptron. The knobs in the middle are the weights. To train it, you turn them by hand, one small nudge at a time, until the needle points the right way.

A similar process is happening inside LLMs. Just with a trillion more knobs and a GPU doing the turning.

Akamai’s CTO Dr. Robert Blumofe built this on his workbench and open-sourced everything — schematics, PCBs, Gerber files, 3D-print frames, bill of materials, the works.

Full 20-minute video walkthrough (super clear and actually fun to watch): https://www.youtube.com/watch?v=PSqP73T0g_M

Complete build guide + all files: https://github.com/rdb64-hobbies/Perceptron/blob/main/BUILDI...

Only basic soldering required. Bonus 3D printer friendly.

This is such a beautiful way to actually get a feel for how neural nets work. Has anyone here built one yet? Would you try it?