This 3D printer solves Sudoku puzzles

Zach Hipps from byte sized turned his 3D printer into a sudoku-solving robot. He added a pen, a camera, and a Raspberry Pi Zero W to the printer in a non-destructive way so that it can still be used for printing.

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Kit list

How does it work?

Zach wrote some Python code to take a picture of the Sudoku puzzle using the camera attached to the printer. Then some image processing using computer vision happens, and the puzzle numbers are input into his Sudoku-solving algorithm which he has running on his Raspberry Pi Zero. Next, the Raspberry Pi generates the G-code for the solution, containing the commands for the printer parts to move so as to write out the correct numbers with the attached pen. The G-code is sent over the serial port to the printer, which makes the pen fill in the Sudoku grid with the solution.

Mesmerisingly neat writing

This is a particularly impressive feat as Zach had never worked with computer vision before. Although he intended it as just a toe-dipping project, he managed to make a 3D printer capable of solving a Sudoku puzzle in seconds. Way quicker than humans. I’ve been known to take days. But I don’t number so well.

sudoku solving robot
Zach with his puzzling machine

Hang on, what IS computer vision?

It’s a type of Artificial Intelligence (AI) that allows a computer to analyse, classify, and process what a connected camera is “looking” at.

Right. Now what’s G-code?

G-code is a super popular CNC (computer numerical control) programming language. It’s used a lot in manufacturing to control automated machine tools, and it’s used by 3D printers.

Sudoku race

Well, that ended badly

In a follow-up video, Zach put his Sudoku-solving robot to the test by seeing how many puzzles it could solve in the time it took him to solve one. Spoiler: the printer is miles better than Zach. But Zach is better than me so, that’s something.

All the project files for this build are available on GitHub.



This is what we’d call a plotter.

Liz Upton

A marvellously over-engineered plotter, with some nice problem-solving in the video. Would blog again.

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