working with printf and scanf...

Posted by kafix

on Oct 23 2006 01:23 AM

Ive been working with some simple serial comm stuff with the VSP on the LM3S811 Dev Kit. Just altering the example program a bit. I'm curious if it is possible to easily implement the printf and scanf commands with this dev kit. I'm totally new to the stellaris, although i work with the 68hc12 quite a bit in my studies, this is new ground for me. I don't know if printf and such will work through the UART, im guessing though, so any comments or code is greatly appreciated. Looking for some direction. Thanks.

Posted by westfw

on Oct 23 2006 02:41 AM

Intellectual825 points

printf and scanf are pretty open ended, once you take into account things like floating point and the format variations that are defined but seldom used. pritnf/scanf have traditionally been a real problem for embdedded compilers, since the desirable implementation only ends up including code that is actually needed.

It's probably possible to implement a useful subset of printf/scanf (%d%c%s) with nearly any C dialect. It can be useful to add your own format designators for something common in your embedded design (%e for an ethernet address, anyone?), but there's a trap there once you go off in a direction that isn't "standards compatible" (even if you do it before the standards get written...)

Posted by kafix

on Oct 23 2006 20:46 PM

Prodigy50 points

i can see what you mean. im more or less looking for (developing, or attempting to at least) a substitute for printf/scanf. im working with the UART stuff to kinda of streamline the process of serial IO stuff. hopefully this will result in some simple one line function calls to read n write to the serial port. I havn't gotten far with reading from the serial port. If anyone has some example code for reading from the serial port please do share. also, I noticed the absence of an itoa function. i suppose integer to ascii conversions can be done without to much hassle. just curious is there is an library with itoa for the keil compiler.