Understanding Arduino UNO Hardware Design - Technical Articles
Circuit design software that makes it easy to design, document, and debug electronics projects for the breadboard (more info in the comments). Would you find this useful? (x-post with r/ArduinoProjects) : r/arduino
Arduino simulator AND
How to Read the Arduino Schematic Diagram | LEARN @ CIRCUITROCKS
ARDUINO UNO WiFi REV2 — Arduino Official Store
Collaborative Design and Creative Expression with Arduino Microcontrollers (MIT IAP 2017) | Andrew Ringler
Arduino UNO Reference Design | 3D CAD Model Library | GrabCAD
Understanding Arduino UNO Hardware Design - Technical Articles