Last summer, I was doing some research on how I could connect a floppy drive to a computer over USB, and I ran into a couple of interesting projects. The first is David Hansel's ArduinoFDC, which allows an Arduino Uno to control a floppy drive. This design is technically USB connected, but not exactly what I'm looking for. How it works is that it you operate the drive over a serial terminal, manually giving it commands to write or read. You can also use the XModem protocol to send or receive larger amounts of data, like a disk image. I actually got this software to work with a 3.5" drive, a 5.25" drive, and even an 8" drive (but not really).

ArduinoFDC is very cool, but I'm looking to create a device that acts like a USB-connected 3.5" floppy drive, in the sense that it shows up on your computer similarly to a USB drive or some other form of removable storage. As far as I know, the Arduino UNO itself doesn't support this functionality. So, onto a different solution.

I then came across Adafruit's Adafruit Floppy library. This looks closer to what I need. Making use of a microcontroller that can present itself as a mass storage device, such as an RP2040, it can act like a regular USB 3.5" floppy drive, as seen here, and could also be connected to a 5.25" drive and potentially even an 8" drive.

If I were to create a USB 5.25" drive, I would most likely end up using the Adafruit Floppy library and a RP2040, and 3D print an enclosure for it to make it an all-in-one unit. The one issue would be powering the drive, as 5.25" drives use a 12v line along with the 5v line, and so powering it from just a USB port wouldn't be possible. I would probably just have power and data separate, using a 12v barrel jack power supply input for power (internally stepped down to 5v) and a USB cable for data.

Unfortunately, while I do have a plan in place, I don't have the time to continue with this project right now, and so I'm marking it as "shelved". However, I plan on pursuing it in the future, so keep an eye out!