Fixed point arithmetics TMS570LS0432

Vytautas Bau��a said:

 Hello,

I would like to use a PID controller with fixed point arithmetics.

So far I tried using "Cortex-R4 CMSIS DSP Library", which isn't flexible at all. Description of functions is dim. And for my specific implementation q15_t type doesn't seem to provide sufficient variable range (-2 to 1.99...).

HW: True. In CMSIS library, q15 is defined as a 'short', which mean the range is from [-1,1).

1)So, is IQmath (used for C28 family, "tidcs\c28") suitable for TMS570LS0432 microcontroller? Because this library has a whole different scale of support and for me it seems more comprehensible.

HW: We don't have completely IQ_Math libary today. The C2000 IQ_Math libary does not apply to Hercules devices.

2)If yes, how can I get it running on my board with PID implementation.

HW: I did some preliminary evaluation with the IQ_Math libary, providing about 10 functions in this evaluation. Go to http://processors.wiki.ti.com/index.php/RM46_CNCD

Search for "fixed point". There are projects building in fixed point for SMO/QEP PMSM and a projects building in fixed point for IntraSPIN BLDC with this preliminay lib. As it is a preliinary lib, we dont have documentations.

3)I had a suggestion of using "motorware" library, could you point me how better or worse this library is, compared, to "tidcs" or "CMSIS".

HW: Motorware is very similar to controlSUITE. It provides those typical functions in motor area. The difference between Motorware and controlSUITE is the code convention. It is nothing about IQ, cmsis.