RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
Summary
RotaryCell documents a reversible hardware project to convert a traditional rotary telephone into a self-contained, battery-powered cellular device using an ESP32-S3-based LilyGO board. It preserves the original handset and dial, adds non-destructive electronics, and provides firmware, hardware wiring references, and assembly guidance in an MIT-licensed engineering archive. The work demonstrates embedded hardware integration with cellular modules and serves as an open-source reference for DIY hardwiring projects.