printf to UART

Hello Vincent

I am not sure about CCS settings, but the following remap would be useful.

#define UARTprintf(...) printf(1, __VA_ARGS__);

Regards
Amit

Amit,

Thank you for your response.  Something I forgot to mention is that I need floating point support.  It is my understanding that UARTprintf() does not support floating point.

I have started looking at this document, www.ti.com/.../spra861.pdf

It states, "This application report presents a sample implementation of a user–defined device driver." While it seems to provide some in depth description, I do not see any sample code.

Hello Vincent,

You may want to use %d to represent the data for integer and fraction point representation. You can see the same has been done in Sensor Hub Booster Packs example

Regards
Amit

Amit,

Thank you for the fixed point example. I understand the advantages of fixed point representation. In the long run I would prefer it.

However, I am setting up a project to port over an existing application on an MCU from one of TI's competitors. This application on the other platform supports full printf functionality with floating point. For the migration of the application to TI to be considered successful, it would be helpful if I could support full printf functionality.

Hello Vincent

Yes, I understand the requirement to be able to support full printf with floating point representation, but right now there is none and it would not be anytime soon that we can add the same

Regards
Amit

Why? Is full printf (or fprintf) support with floating point possible? Does TI RTOS support it?

Hello Vincent,

I was referring to the TivaWare UARTprintf and not for the printf in TI RTOS.

Regards
Amit

isn't there an sprint or maybe better a vsprintf in the compiler library?

Although non-standard there is often an ftoa or dtoa function which carries a lot less overhead than the (vs)printf functions.

The usual re-entrancy caveats apply of course, especially to the printf family.

Robert

That might be a good interim route. I will look into it further. Thanks.

Hello Robert,

No. The TivaWare does not use the sprint or vsprintf from the compiler library.

Regards
Amit

Amit, I was suggesting using the compiler's (vs)printf functions rather than the one in TIVAWare.

The printf family probably is a bad choice in an embedded application anyway, but it's a quick workaround to the TIVAWare printf limitations since they are already using printf.

Robert

Hello Robert,

OK. Let me check what is the delta delay between the two approaches. Of course we would also need to create a condition where the printf can be mapped to UARTprintf as well. Is my reading right w.r.t. to your post?

Regards
Amit

Amit,

Actually I was thinking more like

(void)sprintf(buffer .....);
put_serial(buffer);

Compiler independent for the most part. Usual caveats on size and re-entrancy.

Robert

Replace put_serial with whatever is appropriate.

Hello Robert

Not clear to me.

Regards
Amit

Hello Robert,

Thanks for the clarification. But would not this mean that UARTprintf be still supported in addition to the new "printf"?

Regards
Amit

Yes,

And you could use it within myprintf as the PutSerial routine if desirable. You can even still use printf but it would be inadvisable in most cases to do so and mixing the library printf and myprintf in the same file would be asking for trouble

Robert

I 'borrowed' some of the example from

embeddedgurus.com/.../

Worth check the comments for cautionary notes

Robert

Hello Robert,

Indeed a good read and resource.

Thanks
Regards,
Amit

Amit/Robert,

Some good discussion here. Good info to help me consider what to move forward with. Thanks!!!

-Vince