Mesa 7i95

Its a bit bizzarre that it will not take a 50% duty cycle.
(which you can get by setting the stepgen into quadrature mode)

There should be a way get a constant 30% duty cycle
by enabling the stepgens table mode and having a 10 length table
with 3 on bits and 7 off bits but I cant seem to get it to work ATM
I'll take a look at what's needed when I have a chance.

EDIT
 figured it out, its my fault as usual. I managed to break table
mode in master  when I added stepgen index and reset.
I will fix this ASAP

When master is fixed or if you are running 2.8.x you would set
the stepgen table length to 10:

setp hm2_7i95.0.stepgen.NN.step_type 10

and then set the step table data to 3 on bits (and 7 off)

setp hm2_7i95.0.stepgen.NN.table-data-0 0x00010101

Note that the PWM frequency will be the set rate divided by the table length
so you will need to set the velocity 10x higher than before







 

Tel me about it bizarre to say the least. I did test it as best as I could and bellow 28% it dropped off and above 33% dropped off too.

I was just thinking if 7i95 can run stepgen in step type 3? If it can it is worth trying I guess that would give me on one phase 33% and that might be about good enough.

with what you have suggested how do I enable the table mode?

If you are running 2.8.x, my instructions above should work and give 30.0% duty cycle

if you are running master (2.9.x) I need to push a tiny patch before it will work

I am running 2.9 but if it is easier I will go to 2.8 no problem

Its a bit of a pain to change back and forth because of 2.8 vs 2.9
need Python2.7 or 3.x respectively

Fix for master pushed, not sure how long it will take the buildbot to get up-to-date

ok thanks I will give it a try tomorrow it is getting late here anyway.
thank you I will report back.