Question on Floating Point operations

after the correct compile flags are set, the operation is full automatic.

and very fast compared to the software FP.

software FP is not so shabby, this is a 32bit processor...

if you need to use floating point in an interrupt you dont want to be waiting around that long.

so you would have to choose a unit with Hardware FP.

The 'L4 has only a 32-bit FPU, so make sure you use only float not double. The constants involved have to be explicitly typed as float, best by 'f' suffix, eg.

float a, b;

a = b + 3.0f;

JW

32-bit floats are where real math problems go to die...

Be very careful to understand the numbers and ranges involved in a computation, end-to-end. The ARM implementations don't hold intermediate values at higher precision levels.

From a beginner perspective they seem like a very simple way of solving a problem, but can be a trap.

The FPU-S in the Cortex-M4 is good for DSP/scaling like work. Not good for large numbers where precision is critical for small changes (least significant digits).

The FPU-D used in some of the Cortex-M7 parts, provides for 64-bit doubles, which have a lot more usable digits.

All the platforms have a serviceable software implementations.

Thank you all. I have to use this formula to calculate the current. I don't need much precision.