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
How to make your own Arduino UNO PCB - ATMega328p
Arduino Button Tutorial Using Arduino DigitalRead Function - Hackster.io
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How to make your own Arduino at Home- DIY - SME Dehradun