Simple board to test various USB cables! (Note the USB standard helps to identify these USB-C, cables that are compliant with the standard will have selected pins according to cable and connector specification release).
Plug in your cable to both sides and see which signals light up!
FOR CABLE USE ONLY. DO NOT EVER PLUG THIS IN TO A DEVICE, THE PINS ON ONE SIDE ARE ALL SHORTED TOGETHER AND THAT COULD BREAK IT!
You can buy the boards from just about any manufacturer and build them yourself. Hopefully your fine soldering skills are up to the task (mine aren't)...
This is a Raspberry Pi HAT that implements a PC-style parallel port. GPIO pins are organized as data, status, and control registers. The HAT includes a buffer chip that converts from the GPIB 3V3 logic to signals that conform to IEEE 1284. A 26 pin IDC header on the board connects to your DB25 connector. A parport-gpio driver and device tree overlay integrate the HAT with the Linux parport driver stack.
I wanted to use a parallel port based cooled astronomy camera, but preferred to use the compact and low-power Raspberry Pi over a PC at the telescope. Parallel ports are simple devices. Why not build one?
Hardware, software, and documentation for DC ZIA's 30-in-1 electronics kit badge.
A Mexican company that designs and sells hacker toys, security auditing tools, and educational devices. They even sell products suitable for teaching kids.
Glasgow is a tool for exploring digital interfaces, aimed at embedded developers, reverse engineers, digital archivists, electronics hobbyists, and everyone else who wants to communicate to a wide selection of digital devices with high reliability and minimum hassle. It can be attached to most devices without additional active or passive components, and includes extensive protection from unexpected conditions and operator error.
An open source DIY robotics/rapid prototyping kit much like an Erector set. Lots of standardized pre-milled bars, rods, connectors, and components. Build your own plotter, CNC machine, RepRap, scanner table, or what have you. Capable of three axes of linear motion. Comes with all the electronics you need, including an Arduino, stepper motors, and a motor driver board.
The Shapeoko is an open source CNC that you can either buy as a kit or build yourself for about $300us. Work up your design on a laptop using open source CAD software, clamp feedstock on the bed, and it'll produce what you designed. Because it's open source it's not limited to wood - it could be adapted to just about any material that you can cut or grind could be. Chances are, someone's already done it and posted the docs.
Everything is also kept in a respository on Github: https://github.com/shapeoko/shapeoko