What baud rate is this?

[espcurt]

What is going on here? I have an AdAFruit https://www.adafruit.com/product/284 hooked up to the Tx/Rx of my esp32-c3 module.

Works great, all is fine at 115200 but when I upload a new code image (via the onboard USB JTAG, hooked directly to the D- D+) I get, well this:

download_baud.png (53.23 KiB) Viewed 1353 times

The code uploads/updates fine, whatever is being spammed out of the Tx pin is irrelevant to the function of the chip, (I suspect it's progress info 1%.. 2%.. 3%.. etc..) and am just curious about it.

I've changed to every baud rate I can think of to interpret that stream from 9600-74880 on up to 460800 and 921600 .. stays gibberish.
at 9600 very SLOW gibberish

I know baud mismatch when I see it and that's what this is.. unless it's some kind of Chinese unicode? Anyone know how I can read it? Just curious, it's not blocking development.

[MicroController]

It says "waiting for download" right before the gibberish. That should be the ROM bootloader talking. So I assume that the gibberish is the bootloader responding (in binary!) to the commands it receives from the flash tool, i.e. it expects commands via either USB/JTAG or UART, but sends it's responses to both channels.
The baudrate may be the default 115200 or whatever the flash tool demanded, but the output will remain non-human-readable binary corresponding to the flash upload protocol.

[espcurt]

That must be it, mystery solved! Thanks for the insight.