From: Bdale Garbee Date: Sun, 20 Jul 2025 22:25:55 +0000 (-0600) Subject: document how to bring a v2p3 board up to current schematic X-Git-Tag: fab-v2p4~32 X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=e0959263fd53695118eb8df9418a41765d6f55db;p=hw%2Fquantimotor document how to bring a v2p3 board up to current schematic --- diff --git a/Notebook b/Notebook index 2b35526..2e4042f 100644 --- a/Notebook +++ b/Notebook @@ -495,3 +495,13 @@ - note that the IP2326 boards I bought from Amazon pull up pin 12 with a 51k resistor to pin 13 (VIN), while I have those just directly connected. +2025.07.20 +- updated PCB design to use v_usb for all FTDI power. to achieve this on a + v2p3 board, cut the traces between the 3.3V vias on each side of the FTDI + chip before loading the chip. After loading the chip, jumper pins 3, 10, 11 + together. This will use the internal LDO to provide VDDIO, and pull the + chip out of reset. An open question is whether the Pi will be at all + bothered if no USB cable is attached and the FTDI chip is effective powered + down. Will it try to self-power from the serial port pins and do something + odd as a result? Hope not. +