You are watching a bunch of old fire alarms play the "Benny Hill Theme" (Yakety Sax)
Yep, actual fire alarms playing music.....because why not?
This one is the latest version of the "system" - I rearranged and rewired some things, added some more stable electronics to help balance the audio levels and provide some visual feedback, and added an on-board mini PC so that the whole display is standalone instead of running from an external PC.
Disclaimer: I did my best to try to read and understand the Fair Use Doctrine that is part of US Copyright Law and I do believe this qualifies….I hope. I am in no way attempting to infringe on anyone’s intellectual rights and this is very much a tribute to some of my favorite movie and TV themes of the modern age. KZfaq’s explanation of Fair Use needs some work….my opinion.
This is a project I have been working on intermittently for a couple years now...and it is very much a work in progress but I decided at this point it works adequately enough to show anyone who’s interested in such things. This description will contain a brief overview covering what I think are the important points but I welcome any and all comments and questions!
A few details/notes that should help you make sense of what you are seeing:
There is no trickery here - the sounds are being produced by the actual electronics in each fire alarm horn/strobe for the most part.
The strobes have been replaced by white LEDs that are directly connected to the signal input so they are on whenever that horn is on. (I would have loved to be able to sync the actual strobes with the music but that is simply beyond my self-taught electronics knowledge….maybe someday…)
For simplicity’s sake the best way to explain what’s happening is that I have “hijacked” the circuit that actually produces the frequency to make the fire alarm sound and injected my own via a microcontroller and software.
A combination of open source software,very precise timing, an extremely fast microcontroller ( that costs less than 30 bucks!), a MIDI file, a lot of hot glue, and some very tedious trial-and-error programming results in the music you are hearing.
As of now, the bell, chime, and the electromechanical horn are not used - they require a lot more experimentation and learning on my part before they will...the goal is to use them to add “percussion” and better lower end notes to the music.
There is no “volume” - in other words...no dynamics, no ‘loud and soft’ tones...just buzzy square-wave tones. The software is capable of volume - I just haven’t figured out how to do it yet….mainly because it’s got to be done programmatically and it is extremely complex.
Getting the bell and horn to work correctly is also quite challenging and is as of yet beyond my ability…
The music is produced directly from MIDI files - for anyone who doesn’t know what they are , they are basically simply files that contain instructions for electronic instruments to reproduce music. Note frequency, length, instrument time, and timing are encoded in these files and can produce beautiful music on the right hardware.
This entire project is made almost entirely of old junk - the fire alarms themselves came out of working systems that were replaced (I do fire alarm/CCTV/Security work for a living so I have access to a lot of this stuff which often ends up in the garbage…)
This simply would not have been possible for me to undertake without some basic framework from which to work and adapt - and thanks to a clever gentleman who goes by @Sammy1Am, I have that framework available to me. He wrote some software called Moppy2 which is intended to be used to make music with old computer floppy drives and he graciously shared it with the Internet so makers...nerds... like myself could use it to make our own projects.
Here are links to his Github, KZfaq Channel, and my favorite example of his floppy drive music in action:
github.com/SammyIAm/Moppy2/
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