From owner-freebsd-hackers Sun Sep 30 11:36:20 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from mail.shell-server.com (24-109-11-245.ivideon.com [24.109.11.245]) by hub.freebsd.org (Postfix) with SMTP id 987A337B401 for ; Sun, 30 Sep 2001 11:36:13 -0700 (PDT) Received: (qmail 13631 invoked from network); 30 Sep 2001 18:09:30 -0000 Received: from betsy.shell-server.com (HELO there) (192.168.3.2) by erin-rl0.shell-server.com with SMTP; 30 Sep 2001 18:09:30 -0000 Content-Type: text/plain; charset="iso-8859-1" From: Bart Kus Message-Id: <200109301303.08611@EO> To: Bernd Walter Subject: Re: precise timing Date: Sun, 30 Sep 2001 13:10:35 -0500 X-Mailer: KMail [version 1.3] Cc: hackers@FreeBSD.ORG References: <200109301010.07784@EO> <20010930180302.A19621@cicely20.cicely.de> In-Reply-To: <20010930180302.A19621@cicely20.cicely.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG 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