shuppy (@delan) — [archived]

usb3sun sneak peek!

“i sent rev A0 to a board house and it worked perfectly! the design was correct to the best of my ability, so this wasn’t unexpected, but the first revision is always nerve-wracking, more so when it’s your first ever pcb design. the improvement in ergonomics by moving from the breadboard prototype to a proper pcb cannot be overstated. with the breadboard, wires would come unplugged all the time. this can be scary when it’s ground and an external debugger is attached, because i’ve seen potential differences of as much as 55V between the two power supplies when that happens. that said, the usb host ports didn’t work at first. and with the usb stack we’re using, it really helps to have access to UART0 for debug logging, but i forgot to expose pins for that anywhere, so i had to solder a bodge wire. more on that in § usb shenanigans.” “ariashark also suggested i add some led indicators to check the state of the two input power supplies, independent of whether the firmware is running. i have two opinions about leds, which are closely related: most leds on consumer electronics are too bright [and] blue leds are the spawn of satan (derogatory)” “my first experience with fusion 360 was being forced to create an account and log in to use this piece of software that i had just installed on my computer. this is ostensibly for licensing reasons (you can only have 10 files on a free licence), but to me this is almost as bad as nvidia asking you to log into your fucking graphics driver.”

usb3sun is an adapter that lets you connect usb keyboards and mice to old SPARCstations.

i wrote about the prototype version back in january, but since then i’ve turned it into a proper pcb, and after a couple revisions it’s more or less ready for sale!

stay tuned for the full writeup :)