Smonson's untitled simple harddisk project

[Smonson]

Heyo,

Just keeping this thread updated on what's going on.

I've put 2 of these boards together now and they are both solidly reliable for use as hard disks. Speed seems limited to 600KB/s now, the 1.1MB/s reading might have been a fluke/glitch. But anyway, 600KB/s is still ridiculously fast.

I've tested the real-time clock is able to run and keep time via the backup battery which is a CR2016 coin cell (43 years worth of energy according to the datasheet). I would have used a CR2032 - because everything else does - but I wasn't super confident the holder would fit under the board, the space is only 4mm tall. A CR2025 might fit...

My main job at the moment is writing utilities to get and set the clock on the ST. Got stuck on writing DMA to the peripheral, the official docs are pretty light on info. They give an example only for read, not write. For now I'm only receiving zeros from the ST. But I'll figure it out eventually.

The whole project is on github now at https://github.com/smonson78/smonson-disk, warts n' all.