PSoC Analog and digital blocs on the same chip

[amplexus]

I think the cypress psoc family deserves much more attention, a microcontroller with analog and digital blocs. It programs in c using psoc designer, or you can use psoc express to quickly prototype a design, define inputs and outputs add some logic statements and transfer functions and it will automaticly design your schematic, give you a professional data sheet and automatically generate all the c code needed, days of coding done in minutes. Plus it has powerful simulation features, you can simulate all or part of the design and easily make changes as needed. Even if you know relatively little analog design it will walk you through it. It can dynamically change things like adc or dac resolution on the fly depending on sensor inputs effectively giving you up to 400% silicon usage. Tons of prebuilt designs and ap notes,video tutorials etc incuding several stepper and servo referance designs for you to tweak.

Amplexus

[amplexus]

Cypress has a nice industrial stepper design, sine/cosine using a pair of dacs but it is a noisy chopper. See an43679 for details, still, it is better than allegro or ST. It is built with a PSoC, analog and digital blocks plus a microprocessor, very flexible and cheap. I contacted one of the engineers that designed it and it turns out to be a simple fix to make it synchronous, async kill just needs to be changed to sync kill. This is a built in instruction and the frequency is already fixed, so it should be quiet as a gecko with this change. Once I pointed this out they agreed to fix it with the next revision. I also offered some suggestions for adding midband resonance compensation and low speed morphing which they say they are giving serious consideration. Even if they don't impliment midband and morphing there is nothing stopping all of the talented designers on the forums from doing it. The H bridge could be moded to suit voltage and current needs. It has the potential to be a great open source board, no gecko but still very nice.
Amplexus

[Konstantin]

I read peak current for an43679 is 3A, what is the normal operation max current then?

Do you know about pricing?
It sounds interesting but I am not very good at understanding all tech talk in the datasheet. How does an43679 bests SLA7062M ?

[amplexus]

You are comparing apples and oranges, the an43679 is an aplication note not a psoc part number. I have nothing good to say about the allegro chip or the company, it's flaws are widely documented on the forums. As far as current and voltage goes it depends on what mosfets or igbts you choose for the H bridge, igbt's can run to 6500v or more and over 2500 amps. mosfets should be sufficient for most stepper drivers. 600v - 10 to 100 amps. There are plenty of H bridge designs on the web. The psoc can give you an easy path to a quiet pwm drive, you need to change async kill to sync kill. I talked to one of the engineers at cypress that did the reference design and he plans to change it, he is also looking at midband resonance compensation and low speed morphing. Mariss is also doing a cpld coolrunner tutorial with synchronous pwm. Far better than the allegro chip. Pricing is a buck or two for the coolrunner $2-$9 for the psoc depending on features and i/o pincount. If you just want to get up and running quickly and easily buy a gecko vampire, none of the diy solutions can match it.
Amplexus

[mbosko]

@amplexus

Thanks for your comments about Psoc 1

Three years later AN43679 is still under construction ( or five years from first publishing)
I wonder if engineers at cypress don't have reliable solution what is chance for occasional users of psoc 1 to make something usefull

Do you have any news about AN43679 project ?

thanks

[H500]

I played with one of the Cypress stepper designs years ago and was left with the impression that they did not actually build anything to test, and that the write-up was purely theoretical. For example, the comparator on the chip I tested had too much offset to function properly in the circuit.

[mbosko]

So far I found only one person in the world with "promising" results for psoc 1 stepper ?
PCB for stepper is visible in AN43679 , but not as KIT
There is app note with psoc 3 ,but PSOC 3 will cost you 20 $++