Have you ever wanted to build your own Arduino from scratch ... [Pratik Makwana] starts by showing how to design the circuit schematic diagram in an EDA tool (Eagle) and the corresponding ...

With this free web app, you can build circuits from scratch using three popular Arduino boards — Uno, Nano, and Mega ... containing your program, schematic diagram, and Wokwi link.

it’s great for a quick-and-dirty circuit diagrams. Not exactly schematics, but [Duckman] has some Arduino pinout diagrams he made using ASCII-art. These could be useful when pasted into source ...