300baud not working

The following code did not work

thank you

Just curious as to why such a slow rate ?
Also what board as some will work fine such as the MKR series (your sketch works great on these) ?

It does seem to be an issue but I will refer you here so you can follow it back to the source

Thankyou. I was testing a sensor using UNO and simulating a slow narrowband link on an HF (high frequency == shortwave) radio link. Many of these circuits still use RTTY running at 300baud. But no matter. The test case is unlikely to occur in practice.

I wonder if you may have more luck trying software serial ?

Am aware of slow speed transmissions as I have a UK HAM radio licence.

ok will do. Great! 73