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1. minute (mntmn@mastodon.social)'s status on Thursday, 24-Oct-2024 04:17:29 JST minute

   getting to the finish line with MNT Reform Motherboard 3.0 (yeah, bumping the major rev). many little changes and cleanups today. for example the 5V supply rail size and capacitance for USB has been greatly increased. there's a new direct power header. there's a dip switch to select which console UART you want on USB-C PD port for debugging (plus System Controller UART). i'll probably add a qwiic (i2c) header for access by the SoC tomorrow.

   • minute (mntmn@mastodon.social)'s status on Thursday, 24-Oct-2024 04:30:17 JST minute

     in reply to

     • Graham Sutherland / Polynomial

     @gsuberland good point!

   • Graham Sutherland / Polynomial (gsuberland@chaos.social)'s status on Thursday, 24-Oct-2024 04:30:18 JST Graham Sutherland / Polynomial

     in reply to

     @mntmn on that note, I genuinely wonder if it makes sense to calibrate your VUSB buck converter's output voltage to somewhere near the highest level you can get before its upper regulation tolerance would exceed the USB spec. so if you've got ±1% on your buck and the spec is ±5%, aim for something like +3% (5.15V) to compensate for all the parasitics in the cable.

   • Graham Sutherland / Polynomial (gsuberland@chaos.social)'s status on Thursday, 24-Oct-2024 04:30:20 JST Graham Sutherland / Polynomial

     in reply to

     @mntmn I appreciate any and all efforts to try to make VUSB not utterly shit. normally the only thing worse is automotive 12V.