Thread: casting 4 chars to long int

But.. you don't need that union or to use a pointer to use the 12 bits ADC from PIC18x:

Code:

  uint32_t value = (ADCRESH << 8) | ADCRESL;
  double flt = (double)value / ((1 << 12) - 1);

Make sure ADCCON0.FM bit is set.
(Assuming 'double' has 53 bits of precision here).