topic Re: Problem with Freescale Compiler in 8-bit Microcontrollers

Problem with Freescale Compiler

MarkusWimmer — Fri, 05 Jun 2009 02:55:33 GMT

Hello, i have some trouble with my programm an i hop you can help me.

Her my code

for(;
{

        int result;
        float voltage;


        ACMP1SC = 0x00; //Analog Comperator ausschalten

        ADCSC1 = 0x22; //Kanal 1 Messung jede Sekunde
        while (!(ADCSC1 & 0x80))
          ;
        result = ~ADCRL;

        voltage = 4096/1023*result;


}

The Compiler error is

"Link Error : L1822: Symbol _FSFLOAT in file C:\Users\Markus\Desktop\BAUVORHABEN\BUS_SYSTEM\SOFTWARE\EINFACHE_ROUTINEN\Analog\Analog_Data\Standard\ObjectCode\main.c.o
is undefined
Link Error : Link failed"

What´s wrong with this code??

Thanks Markus

Re: Problem with Freescale Compiler

pgo — Fri, 05 Jun 2009 09:31:30 GMT

Dear Markus,

It looks like the floating point library is missing.

When you created the project did you select the floating point option? It appears at the bottom of

one of the New Project Wizard dialogues.

bye

Re: Problem with Freescale Compiler

CompilerGuru — Fri, 05 Jun 2009 09:54:56 GMT

As Markus already explained, you are using a integral only library.

Check if you do need indeed floating point numbers, for a small 8 bit chip using integers (including longs) is much efficient.

Also

voltage = 4096/1023*result;

is not actually performing the computation in floating point arithmetic, instead it computes

voltage = 4*result;

4096/1023 is 4 (int type), and not 4.0039100684...

Daniel