The embassy_serial example seems to be broken

[jessebraham]

This was confirmed on ESP32, possibly affects other chips. Needs more investigation.

[bjoernQ]

Looking into it, it might do what the code says. It's just a slightly weird example

Also it's not correct to return a len of 0 if there is no data to receive ( https://docs.rs/embedded-io-async/0.6.0/embedded_io_async/trait.Read.html#tymethod.read )

[elpiel]

Yes, it's correct. Receiving over UART is currently not working for ESP32-C3 as well.

PS: Please consider dumping the UART received data in the example as it's not that clear what happens in the receive loop.