Floppotron's Epic Upgrade Is Epic
512 floppy drives consuming 1.28 kilowatts for magnificent stepper motor songs.
On YouTube, Paweł Zadrożniak's Floppotron is an iconic source of electronic music. Floppotron can recreate a wide range of songs by manipulating the stepper motors in floppy drives, hard drives, and scanners. Over six years, it performed 128 cover songs, ranging from "Layla" to the "Super Mario Bros Theme" and everything in between. So there was a sense of sadness among Floppotron's fans when Zadrożniak released a video titled, "Time to Say Goodbye." Thankfully, a week later, Zadrożniak introduced Floppotron 3.0 — an epic upgrade to an epic machine.
In July 2016, Zadrożniak introduced the previous Floppotron with a rendition of the Imperial March from Star Wars. That version of Floppotron consisted of 64 floppy drives, eight hard drives, and two flatbed scanners. While this music machine was named Floppotron 2.0, it was the first floppy-drive music maker with the name. Previously, Zadrożniak demonstrated a project called "Floppy music Duo," with two floppy drives playing a simpler version of the Imperial March.
Devices like floppy drives can make music because of the stepper motors that move their read-write head. Inside stepper motors are multiple coils of wires, which, when activated in a sequence, allow a rotor to turn. Those coils are similar to the coils found in a speaker's driver. So, by changing the signals driving the steppers, you can create an audible output.
Particular movements of the drive head, or the scanner's gantry, can cause the steppers to "sing" at specific frequencies. Musical tones are frequencies or combinations of frequencies. So, with careful planning, it is possible to map musical notes to these stepper motor movements.
As Floppotron demonstrates, floppy drives are excellent for high-frequency tones, while the scanners do well at lower frequencies. Floppotron uses the head of a hard drive to simulate percussive instruments (or drums.)
The Upgrade
Floppotron 3.0's upgrade is epic in proportion to the previous instrument. Now it has 512 floppy drives, 16 hard drives, and 4 flatbed scanners! Not only that, but the scanners now have RGB LED strips. These strips simulate the look of a neon tube and help indicate which scanner is playing notes. The hard drives also now have an RGB LED as well.
When looking at these new specs, two things come to mind. The first is, how much power does this thing consume? And second, how is it possible to control all of that hardware!
Floppotron 3.0's power supply is 16 modular 5V/18A supplies mounted in a standard 19-inch rack. Zadrożniak says the average consumption is around 300 watts, but if all 512 floppies are active, Floppotron 3.0 can peak at 1.28 kilowatts!
A PC plays the notes through a gateway that connects to the drive controllers. The gateway receives MIDI messages from the PC. MIDI is an ideal fit since it is a digital standard for music devices like a synthesizer (keyboard) to communicate with other instruments. The drive controllers talk to the gateway with RS485.
The gateway itself uses a Nordic Semiconductor nRF52840 SoC. Zadrożniak says that a passive MIDI-to-RS485 adapter might have worked. However, this setup adds extra information to the encapsulated MIDI messages over RS485. The devices connect to the controller with RJ45 cables in a star topology. Those controllers use an nRF52832 SoC and a driver circuit for the particular device (FDD stack, HDD, scanner.)
In the future, it may be possible to eliminate the PC-to-MIDI adapter used now and get more bandwidth by using the nRF52's native USB port to talk to the PC. Or even DMX-controlled lighting!
For now, Zadrożniak says Floppotron 3.0 has a few more bugs to work out but promises more music covers will be coming soon! To learn more about Floppotron 3.0, check out this extensive blog post with many build details and plenty of pictures.
