LPT problem

hi to everybody,
I am trying to pilot two cards for step motor through parallel port, that needs 2 signals:
one of direction on - off, the other of step (clock).
the problem is that using the box port (device) no I succeed in reaching a high speed.
is it a limit of the program or mistake something?

stepper2.v4p (11.1 kB)

is it a limit of the program or mistake something?

Yes, there is a limit in the concept. vvvv organizes everything in individual frames. You can do only one operation in one frame, which means you van change the value of the port only once in a frame - so you are limited in the maximum speed in which you can toggle your port bits. we may change the port object to allow for some programmed bit sequences at one time, but this is currently not on the list.

If you dont have any complex rendering needs it might help to set the Presentation Interval pin in the Renderer (EX9) to Immediate, and use MainLoop to set the framerate to something more than the default 60fps.

Anyway even if vvvv would allow doing this, Windows is not a realtime operating system and you will have difficulty doing clean pulses of several hundred Hertz alone in software.

So you might be better investing in an arduino board and doing the timing of the pulses there. The HowTo Motors wiki page gives some more tricks.

hi and thanks for the answer,
I imagined pits a limit of the program, I hoped to mistake me.
in my patch I don’t use blocks render as I do to plan the fps to 60?
had I thought about the port RS232 or DMX but do they seem me enough difficult, perhaps with arduino?
talk to you soon

using rs232 or dmx in vvvv is much easier than learning how to control stepper motors with arduino…

I have tried your suggestion, the value 60fps in the box Mainloop(vvvv) has worked, the motors stir very more quickly.
for now I avoid to use DMX RS232 or other.

If you need more smooth operation, just have a look at the german comany “trinamic”. They can provide controlboards for steppermotors, which have a certain piece of intelligence, programmed in a specialised language.
With this way it is possible to send a command in a frame performing a more complex action like speed ramps etc. by the controller hardware.

Greetings from a trade fair based in the hometown of vvvv ;-)