Here’s a fun rabbit hole to run down if you don’t already have the RP2040/RP2350 PIO feather in your cap: how to serve data without CPU intervention using PIO and DMA on the RP2350. If ...
Rivian’s recommended method works like this: pull off a door card panel that sits toward the rear of the door itself. Inside, you’ll find a pull tab that, when pulled, will manually open the door.