Presented here is an Arduino-based "Blue Box". It produces the "traditional" Blue Box 2600Hz tone and MF (multi-frequency) tones, but does much more! It also produces 12 tone signalling systems used ...
The classic guides on Arduino melody like [this guide on Arduino.cc](https://www.arduino.cc/en/Tutorial/BuiltInExamples/toneMelody) and notes on [Play Arduino Piezo ...