Hi everybody,

On a 80C320 micro project,
I need to make a function generator to feed a PID function.

I would like to know if somebody can help me choosing the
best method.

Program will be written in C language.
As the routine will be called in periodic interrupt, I cannot use
math functions in it (takes too much operations) I think we need to use
lookup tables (not too big !!!)

I need to generate a 16 bits word at frequencies from 0.01 Hz
to 250 Hz assuming I need at least 20 points to describe the sine wave
when in "high" frequencies. When working in low frequencies (< 0.1 Hz)
I need more than 20 points (perhaps 50 , 100, 200 ...)

The setpoint frequency can be choosed from 0.1 to 250 Hz with this
0.1 Hz increments, and from 0.001 to 0.1 with this 0.001 increments.

Please give me your suggestions.

Thanks and best regards.

Elia.