compilation error

[ChrisT66]

Hi, when I try to compile with the macro ‘SetBaud’ I get this error (and other similar ones):
error: ‘UBRR1L’ undeclared (first use in this function)

What exactly does this mean?

Thanks and best regards Chris

[LeighM]

The macro has C code which has been written for a specific target device,
so won't work with a different device.

[ChrisT66]

Yes exactly, also for the ATMEGA328P that I use

[medelec35]

If you change the target device to one that does contain all the SFR's e.g. ATMEGA640 then the code will compile successfully.
Is there a reason for creating your own C code?
I would recommend if it's for learning, check register names within the microcontroller datasheet first.
ATMEGA328 only contains UBRR0H/L, all the other register e.g. UBRR1H/L etc are missing.
Hence reason for failing to compile.

[ChrisT66]

Unfortunately, the normal ‘ChangeHWBaude’ function for the UART does not work. There have already been posts about this here...

[medelec35]

Unfortunately, the normal ‘ChangeHWBaude’ function for the UART does not work. There have already been posts about this here...

In that case, thank you for letting us know.
I will put it on my list to investigate, so you won't need to use C code.
If I replicate it not working, I will move the topic to Bugs.

[ChrisT66]

Ok, then I hope you find the error, thanks!

[medelec35]

As you have not added 9 or 10 post icon, I will assume you are using FC10.
Just tested on the Uno and ChangeHWBaud is working as intended, toggling between 4800 and 19200 .
Analyser set for 2400 & sending U:

ChangeHWBaud1.png (53.08 KiB) Viewed 1944 times

Do have an example .fcfx project where it is not working?

[ChrisT66]

I have to generate a new project first, I can do that. I'm not using a UNO etc. but the chip direct, an ATMEGA328P and 328PB.

[ChrisT66]

I have tested it again, I am transmitting from one module with 115200 baud to another. If I configure the UART of the receiver module with 9600 baud and then set it to 115200 with ChangeHWBaud after initialisation in the program, it does not work.