Getting errors when using pointers... plz help

Projects Programming
1

Hey everyone,

Just started using pointers :slight_smile: , here is my code which is getting an error I will display after.

This is a global function I have created which causes the error:

void mk7sixt() {
  
  if (sMode == 1 && m_sys == 1 && m_vs1 == 0) {pBit = &m_sixt1;}
}

However the compiler says the error happens when it is called in the Setup() area here:

     byteVal = 0;                          
      for (int i=3; i>=0; i--) {              
      bitWrite(byteVal, i, shiftdata0[i]);
      if (i == 0) {
        svalueI = fourPos(byteVal);
          paramList[3] = svalueI;

          if (syAorM == 1) {
            mk7sixt();             //<-- THIS IS WHERE THE FUNCTION IS CALLED (line 422)
            bitClear(*pBit, 3);
            if(svalueI == 0) {
            } else {                                      
              bitSet(*pBit, 3);
            }
          }

        }
      }

And here is the error:

sketch\C-MKS7-d-July5.ino.cpp.o: In function setup':** **C:\Users\dmorr\Documents\arudino projekts\C-MKS7-d-July5/Setup.ino:422:(.text.setup+0xd5a): relocation truncated to fit: R_AVR_7_PCREL against no symbol'
collect2.exe: error: ld returned 1 exit status
exit status 1
Error compiling for board ATmega1284.

The goal of this mk7sixt() function is to simply change the address of the pointer pBit so the bitclear/bitset operations execute on different variables, depending on those conditions. You might be wondering why I am calling a function with only one if-statement, well there were lots of if-statements in the function originally, but even with just one if-statement I still get this error, so something about the way of assigning this pointer an address is causing problems (i think?? :confused: ), but I have no idea why. All variables are byte types and all variables are global, so there shouldn't be any scope issues... Any insight would be greatly greatly appreciate, thank you!

2

Okay I think the solution here is possibly you cannot always fit the address of some memory location into the byte type variable, you need to use int.

3

Where’s the definition for pBit?
You can’t have a pointer to a bit for a start, if that’s what you are trying to do.

4

sorry that variable name is confusing, it was meant to be pByte and the variable definition was:

byte *pBit;

But I switched the variables to be integers instead of bytes and now things are compiling, I’ll test it tomorrow but that seams to have solved it.