I'd been meaning to look at postcard-rpc. I know we'd talked about the schema hashing, but interested to see how it works in practice. So far it's looking pretty exciting. Since the PC is going to see a UART bridge, device ID matching would work. Question is if we can change the existing protocol.

Existing line-based ASCII stop-and-wait protocol isn't too bad (despite being unable to decide if numeric values are decimal, hexadecimal or hex-encoded bytes), but I get nervous when we start throwing dozens of requests per second and some are blocking. Got to async all the things.