A "musical" siren for bicycles.

This design was published in the Circuit Notebook section of the Februrary 2022 issue of the Silicon Chip magazine. Feel free to have a look there if you would like a nice explanation / writeup of the horn's operations and construction.

1. Modify the Arduino nano for low power and low voltage usage.
2. Build the circuit - see BikeHornPCB for a PCB design. The siren is from an old smoke alarm.
3. 3D print the case.
4. Optimise parameters for each note to be the loudest possible - see Tuning for details.
5. Generate the tunes to play using this Musescore plugin. Paste this into tunes.h in the main BikeHorn sketch.
6. Upload to the Arduino and test.
7. Mount on bicycle / vehicle and have fun.

See the Silicon Chip section or the Images directory for relevent diagrams and images of the horn.

A low resolution gif that gives an idea of order of assembly:

I have attempted to make the firmware fairly modular and most non-core parts have been included as externsions. This allows for easier maintenance and customisation. For more details on enabling, disabling and writing extensions, please see the extensions documentation.