quadrature signal output for stepper

hi all,

i am designing a microstepper board which is microcontroller based and was reading under the manual section: basic configuration> maximum step rate, that you can configure emc to output a quadrature signal instead of step/direction. this is from the manual: " If your stepper driver can accept quadrature input, use this mode. With a quadrature signal, one step is possible for each BASE_PERIOD, doubling the maximum step rate."

I've searched everywhere in the manuals and on the forums but found no clue on where to start to configure emc in such a way.

i have some experience with Hal, so please could anyone tell me where to start? what components i should use and maybe how to connect them?

thanks in advance

ah so what i need to do is change the step type from the stepgen component.

thanks for your fast response, once i get home I'll try it out. can't wait

ok so I managed to set it up - peice of cake thanks to that manual

however i got nowhere... no improvement at all. with my current base period of 30us, using step direction I can jog my 24microstepped axis at about 85mm/s, if I go any higher i get a following error which makes sense since at that speed, the step pin is switching at 30khz.

when i change to quadrature signal, the frequency on each phase is reduced by half... but still, if i go past the 85mm/s barrier i get a following error.

I thought the output steprate would have doubled whilst maintaining the same base period... did i do something wrong or missed something ?

ok so I managed to set it up - peice of cake thanks to that manual

however i got nowhere... no improvement at all. with my current base period of 30us, using step direction I can jog my 24microstepped axis at about 85mm/s, if I go any higher i get a following error which makes sense since at that speed, the step pin is switching at 30khz.

when i change to quadrature signal, the frequency on each phase is reduced by half... but still, if i go past the 85mm/s barrier i get a following error.

I thought the output steprate would have doubled whilst maintaining the same base period... did i do something wrong or missed something ?

yes the parport signal of step dir is inverted since im using a not gate as a buffer board

after thinking about everything, seeing the scope traces, I was already getting one step for each base_period with step/dir so there is no going faster than that whatever I do.

I tought that maximum step rate was limited to the amount of changes of a pin of a parallel port. That is: if I used step type 4 (3-phase output where a specific pin changes state each 3 steps) I would be able to get 3 times faster than using step/direction. but from what I can understand its not the actual pin changes that are limited by base_period, but the actual steps generated by the system. is that right?

ok now i understand the whole story....

so when the documentation said that quadrature doubles the maximum steprate over step/dir, is only applicable when not using the reset function....

without using the reset function the step pin could only turn on in one base_thread and then turn off in the next one.


still as you said quadrature makes much more sense and i will try to design the driver for that.


thanks for all your help to both of you, you thought me a lot.