Date: Sun, 30 Sep 2001 13:10:35 -0500 From: Bart Kus <bsd@shell-server.com> To: Bernd Walter <ticso@mail.cicely.de> Cc: hackers@FreeBSD.ORG Subject: Re: precise timing Message-ID: <200109301303.08611@EO> In-Reply-To: <20010930180302.A19621@cicely20.cicely.de> References: <200109301010.07784@EO> <20010930180302.A19621@cicely20.cicely.de>
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On Sunday 30 September 2001 11:03, Bernd Walter wrote: > Controlling steppers via lpt is what I explained and showed last > tuesday on the cosmo-project meeting. > We used nanosleep() which worked fine for the demonstration and > playing. > As long as you don't have troubles with longer than requested periods > this would fit your needs. Is there a record of your explanation somewhere? As for the longer-than-requested timing periods, yes that is a problem. If maximum velocity of the drill is 30cm/s, a sudden stop would not be good. I can of course change the MAX_V, but I'm still hoping for a non-kludgy solution. > Nevertheless in my opinion it's a job for a dedicated CPU/controller. > Think about using an 68HC11 or something like that. > If you can enshure not only minimum but also maximum step times you > can even get the motor faster - well not with lowered drill of course. I agree. This does need a dedicated MCU. However, I only had 1 PCB layer to work with, so simplicity was key here. > You can shorten the steps while the motor is rotating which you can't > do at once. What do you mean here? I already do use variable timing for the steps BTW. Remember, the motors perform constant-acceleration operations...it means they slowly approach MAX_V. It's pretty neat to listen to. :) --Bart To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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