Creating a VGA Signal in Hubris

23 lasernoises 5 9/15/2025, 3:04:24 PM lasernoises.com ↗

Comments (5)

vardump · 2h ago
RP2040 and RP2350 PIO makes producing VGA signals criminally easy.

But many other µCs can do it too, at least to some degree. Even Atmels.

sitzkrieg · 14m ago
my thoughts too. this is a hello world bare metal step up. doing it to get to grips w gpio on a full blown os is cool too though
pipo234 · 1h ago
There's probably a well documented backstory on why Oxide choose stm32xx nucleo. I'm guessing VGA signals were not a top priority for hubris
steveklabnik · 5m ago
The rack has no screens, so no need to drive VGA, it's true.

Probably the best history on the choice of going with ARM comes from here: https://news.ycombinator.com/item?id=28989138

The internal RFD on the SP's design still talks about choosing RISC-V, and I don't think (or am simply bad at using search) that the move ended up being in an RFD.

mkeeter · 11m ago
(I work at Oxide, though I wasn't around for the initial chip selection process)

It's at least partially a matter of timing: Oxide was picking its initial hardware in roughly 2020, and the RP2040 wasn't released until 2021.

A handful of people have done ports, e.g. https://github.com/oxidecomputer/hubris/pull/2210, but I expect to stick with STM32s for the foreseeable future – we've got a lot to do, and they're working well enough!