Ingvar I did test what you suggested and it was RIGHT.
In other words it does exactly the same as FP routines do and at lesser code space cost.
Ofcourse it doesnt solve my problem but it can be used to save space effectively.
I believe that using a converter with greater than 10 bits resolution is a must and if there is a chip suggestion, to make things easy, I am waiting for it.
Thanks again
Bill