Herewith, to nail down the reasons why you can’t (or, perhaps, shouldn’t) use Arduino float variables, a small collection of DDS-oid calculations.
Remember that float and double variable are both IEEE 754 single-precision floating point numbers:
Size of float: 4
double: 4
The Arduino floating-point formatter gags on some values, although they calculate correctly:
2^24: 16777216.000 printf: ? 2^32: ovf or ovf 2^32: ovf 2^32 / 256: 16777216.000
Don’t add values differing by more than seven orders of magnitude and suspect any results beyond the first half-dozen significant figures:
Oscillator steps: HzPerCt Oscillator: 125000000.00 -25 -> 0.02910382461 -24 -> 0.02910382461 -23 -> 0.02910382461 -22 -> 0.02910382461 -21 -> 0.02910382461 -20 -> 0.02910382747 -19 -> 0.02910382747 -18 -> 0.02910382747 -17 -> 0.02910382747 -16 -> 0.02910382747 -15 -> 0.02910382747 -14 -> 0.02910382747 -13 -> 0.02910382747 -12 -> 0.02910382747 -11 -> 0.02910382747 -10 -> 0.02910382747 -9 -> 0.02910382747 -8 -> 0.02910382747 -7 -> 0.02910382747 -6 -> 0.02910382747 -5 -> 0.02910382747 -4 -> 0.02910383033 -3 -> 0.02910383033 -2 -> 0.02910383033 -1 -> 0.02910383033 +0 -> 0.02910383033
The Arduino source code as a GitHub Gist:
