Not exactly schematics, but [Duckman] has some Arduino pinout diagrams he made using ASCII-art. These could be useful when pasted into source code as comments, documenting the pinouts for your ...

Is This a 'COVID 5G Chip Diagram'? The idea that vaccinations will be used by the government to secretly implant tracking devices in humans is a long-standing conspiracy theory.

To bring out the salient features in the eutectic region the section of the diagram shown in Fig. 1 has been restricted to pressures up to 1 atm. Schematic portions are shown as broken lines.

QElectroTech is an open source tool for drawing these types of diagrams. It consists of two tools: an element editor for creating schematic symbols and a diagram editor for creating your drawings.