Hello.
I have noticed that for me Serial Monitor at Arduino IDE 1.8.9 has an issue at baud rates higher
than 115200.
If I set code and monitor to 115200 then I may send data out of Arduino Nano and also I may read any data I type in Serial Monitor into my code once I press SEND button.
The things changing since I just change baud rate at code from 115200 to 230400 (and in serial monitor as well). I still see the data is send out of the processor ok, but for the data I send into processor board I see the following:
The first character I send always arrives as it should be. Then after that characters which was correct next characters are different from whats been sent. So strange. They do look like when you send data using wrong baud rate at receiver. The amount of characters match and first is always same but others not.
What the hint might be here?
What board are you using to connect to the serial monitor? What is your hardware setup? Specifically, what is the timekeeping of the crystal that generates the baud rate?
Hello, Perehama.
Thank you for the reply and will to help.
The board is Arduino Nano ver.4.0. It sends data out of processor using such baud rates
like 115200,230400 and 500000 ok.
The hardware setup is simple - there is only Arduino Nano.
There is another board where Nano is plugged in but I test the serial incoming at
Arduino Nano with Nano fully unplugged. In general I seems cant read serial data
into Nano at baud rates higher than 115200.
The crystal on board is 16Mhz. I'm a bit missed the question about timekeeping, sorry.
It would be a great help if somebody may set a little test code, set baud rate at 230400 and
try to read characters sent manually via SEND option at Arduino Serial Monitor and display them.
It looks at the moment that Serial Monitor may show at any speed but may read input
at only not higher than 115200 baud rate.
In my project I do use output from Nano at 230400. So then I decided that I will send some commands
to Nano to control a digital filter params.
This failed to work at 230400 but works at 115200. The thing is that I need 230400 for output.
Obviously this means that I need to read serial at same speed.
As you can see from this AVR Baud Rate Table, the register UBRR that derives the baud rate from the crystal clock speed is limited in how it can scale. This means an AVR clock speed of 16 MHz can't support baud rates above 115200.