Panic while trying to write to serial using `ufmt::uwriteln` about avr-hal

[BiasedKiwi]

That was it! It does print Hello, World! now. Thanks for helping me out

[Rahix]

Hi, there are two things happening here, I think: First of all, ravedude is crashing with the error message you printed. This is a bug and I've prepared #516 to hopefully fix it. Please give this a try and report back what happens.

The second problem is that garbage data is received by ravedude in the first place. This shouldn't be happening either. I assume it is some problem with the serial connection, but let's wait on the output of the fixed ravedude from #516 - it will most likely make the issue easier to spot.

[BiasedKiwi]

I switched to using #516 and this is what I got ????????????????????????? so all characters in my string are bad apparently

[Rahix]

Hm, alright. Are you sure ravedude is using the same baudrate as your board? In your code I see that you are using 9600 baud:

arduino_hal::default_serial!(dp, pins, 9600);

Is ravedude using the same? In .cargo/config.toml where ravedude is specified as the runner, it should be called with a -b 9600 argument.