First off: thanks for your extensive reply on my queries.
I've been reading very much and also started the PCB designs.
I decided to use a daugter board with the CPLD and it's basic components because I really doubt that I will be able to solder that extremely fine pitch CPLD, if I can't then somebody else could do it for me: just ship the small adapter pcb's back and forth. When all this fails: there are adapter boards with CPLD and basic components available on Ebay...
There's also a very important second reason for this: A few years ago I started a design and used an AVR to control the power section, it worked but needed some fine tuning. Unfortunatly this went on the backburner, other more urgent stuff to do.
If I want to pursue this AVR based drive: it would just need another daughter PCB with the AVR and use the same power PCB.
BTW: this AVR firmware already implemented "morphing", still needing some testing and fine tuning.
Regarding your last post on resonance compensation: I did a lot of reading on this subject a while back and as far as I remember:
- the incoming step pulse is a bit delayed before it actually changes the current in the power section.
- resonance is detected by monitoring the drive's current
- when resonance is detected: a correction is applied by advancing or delaying the current change in the power section.
- The amount of correction is a function of the amount of resonance detected and the motor speed.
Does this match with the Microchip stuff? I would be interested in a link to their solution.
Thanks again and regards,
Luc.