hardware design

Mathologer shows a simple idea, the commutator, that lets anyone who can solve the first layer design their own full Rubik's cube solution. The same idea carries over to other symmetric twisty puzzles such as the Megaminx.

DIY Perks shows how to modify devices that use older USB connectors so they charge and connect over USB Type-C. He solders in a USB-C connector board and works through cases such as dongle-dependent gadgets and a mouse receiver.

Shawn Hymel of DigiKey introduces KiCad and explains how printed circuit boards are manufactured. It is the first part of a beginner series that builds a 555 badge project.

CuriousMarc inspects a newly arrived Teletype Model 19, an early military unit built around a Model 15 keyboard and printer, after an initial rough cleaning. It is the first part of a restoration series and touches on 5-bit Baudot code.

The 8-Bit Guy explains how character LCD screens work and how to control them directly, first part of a series.

Bisqwit writes a NES emulator in C++ in about 15 minutes of tool-assisted, sped-up coding, narrated with captions. It shows an accurate emulator built with a compile-time generated 6502 instruction table. Part 2 covers compiling and running it.

Lock-picking YouTuber Bill Johnson (BosnianBill) explains how to choose a high-security lock and why, showing examples and comparing designs. It covers what makes some padlocks more pick-resistant than others.

Ben Eater shows how to build logic gates out of transistors, including NOR gates. It is part of his clear hardware-from-scratch teaching style.

This Old House's Ross Trethewey explains MERV filter ratings and how air filtration works, then shows how to build a localized DIY air filter, including a box fan with multiple filters.