C / C++ / MFC

Member 6038196 wrote:

where do i go to ask silicon labs questions?

// Declare a union so we can easily access the bytes of a float
typedef union ieee_754_single_precision
{
   BYTE bytes[FLOAT_BYTES]; // Let's hope FLOAT_BYTES == sizeof(float)
   float value;
   IEEE_SBITS bits; // Don't know what this is...
} SIEEE_754;


void cHARTTransmitter::Float2IEEE(float fDecimalNum, BYTE *pbIEEE)
{
   SIEEE_754 local;
   // Set up an index to iterate through the bytes array in local - see my later comment.
   short j = FLOAT_BYTES - 1;
   // Assign the float to the union. The bytes making up the float are now available though local.bytes
   local.value = fDecimalNum;
   
   // Now transfer the bytes from local to pbIEEE, reversing their order 
   // as we do so. It might make it clearer if we replace "j--" by "(FLOAT_BYTES-1)-i"
   // If we look at i and j, we see that
   //
   // pbIEEE[0] = local.bytes[3]; 
   // pbIEEE[1] = local.bytes[2]; 
   // pbIEEE[2] = local.bytes[1]; 
   // pbIEEE[3] = local.bytes[0]; 
   //
   // (BTW - what compiler is this that doesn't require i to be declared?!)
   for (i = 0 ; i < FLOAT_BYTES; i++)
   {
      pbIEEE[i] = local.bytes[j--];
   }
}