L6470 always in stepclock mode

[goeckeritz]

Posted on April 24, 2014 at 13:30

Hey everyone,

I am using a 6470 attached to the STM32F0-Discovery which basically works fine. THe only thing is, that when accelerating and decelerating the stepper is shaking all over the place, even losing steps during a certain period. When looking at the dspin_getStatus() response I see SCK_MOD bit raised, indicating that the device is in step-clock mode though I have set 1/128 microstepping mode in my init routine. I let the motor run at a certain speed and change direction every 2 seconds, just as a test sequence. I use dspin_run() command for this.

Why can't I get out of step_clock mode? Shouldn't this be done automatically when using a move or run command?

I used another L6470 earlier, where I did not have these issues.

Any comment is highly appreciated.

Stefan

#dspin #l6470

[goeckeritz]

Posted on April 24, 2014 at 14:46

Oh hey, I think I got it.

After rechecking all pin connections to the solder pads on my board I found that a phase wasn't soldered properly. So I resoldered all four coil pins and see, everything works like a charm.

It's obvious that when only having one coil under current, behaviour is equal to that of a little child... ;) That explained to me, why most of the time toggeling direction and moving very slowly didn't really work.

Still, one thing though, getStatus gives me 0x9E50 during movement, which means, L6470 works in step clock mode, right? Maybe some issue with SPI implementation sowmwhere?

Hope this helps, in case someone experiences the same wanky behaviour.

Cheers

Stefan

[Ryan]

I know this is an old question, but I have seen this issue trouble a few customers and this question pops up when you search for it.

If the L6470 seems to always be Step Clock Mode or you are seeing other oddities in communication, it is most likely due to an incorrect setting for the SPI clock polarity and/or phase. If this is not set properly it is possible to have most of your communications appear to 'work', but you may still have some issues especially with things like the SCK_MOD bit in the status register which is the MSB that is not being clocked in properly.

This may manifest in other registers or on other devices as well like the L6472, L6474, L6480, L6482 or the powerSTEP01.