c - Is my method of passing a struct as both value and reference correct? -

i have looked @ examples of passing struct both value , reference. code compiles not working should. using c program micro-controller hard check if working properly, not getting desired output.

so, per instructions, first define structure:

 struct package //define structure type called package. {     unsigned char              wavtype,startfreq1,startfreq2,startfreq3,startfreq4,             stopfreq1,stopfreq2,             stopfreq3,stopfreq4,step,dura,amp,sett; //define bytes use  };  

in main method create instance of it:

    struct package p; //create new instance of package 

now pass reference (pointer - because i'm using c) function:

   getpackage(&p); 

within function getpackage() update values of respective elements of p:

 getpackage(struct package *p) //get data package { p->wavtype = receive(); p->startfreq1 = receive(); p->startfreq2 = receive(); p->startfreq3 = receive(); p->startfreq4 = receive(); p->stopfreq1 = receive(); p->stopfreq2 = receive(); p->stopfreq3 = receive(); p->stopfreq4 = receive(); p->step = receive(); p->dura = receive(); p->amp = receive(); p->sett = receive();  }    

this receive function:

unsigned char receive(void) {  unsigned char datar = 0x00;  for(signed char = 0; <=7 ;i++) {      datar |= portbbits.rb1 << i; //move value on data pin bit in datar  }  return datar; } 

question: correctly update bytes in package p? also, package p need returned if want use elsewhere? ask because....

i pass package p, value, function using:

sendsine(p); 

this function makes use of value of bytes in package p:

void sendsine(struct package p) {  datal = p.startfreq1;  datah = p.startfreq2;  send(datal,datah);  datal = p.startfreq3;  datah = p.startfreq4; send(datal,datah);  } 

i know function send(datal,datah) working because have tested setting datal , datah hand , required result, there must error along way struct - cant figure out where... can me might be?

the receive function seems procedure in question. try writing stub-replacement receive, such as:

    unsigned char receive(void)     {        unsigned char x = 'a';          // or whatever value want simulate being received         return x;     } 

and try running complete application, tf works go , re-think original receive per of comments have been made.