From owner-freebsd-hackers Sun Sep 30 13:20:22 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id 8ACD037B40C for ; Sun, 30 Sep 2001 13:20:18 -0700 (PDT) Received: (from dillon@localhost) by earth.backplane.com (8.11.6/8.11.2) id f8UKJvg44890; Sun, 30 Sep 2001 13:19:57 -0700 (PDT) (envelope-from dillon) Date: Sun, 30 Sep 2001 13:19:57 -0700 (PDT) From: Matt Dillon Message-Id: <200109302019.f8UKJvg44890@earth.backplane.com> To: Bernd Walter Cc: Bart Kus , Bernd Walter , hackers@FreeBSD.ORG Subject: Re: precise timing References: <200109301010.07784@EO> <20010930180302.A19621@cicely20.cicely.de> <200109301303.08611@EO> <20010930205859.A19910@cicely20.cicely.de> 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 You definite need to use a microcontroller. Something like the 68HC11F1 is a good single-chip solution (though the F1 only has 512 bytes of E^2). I'm sure Motorola has newer chips with more on-board E^2. Stepper motors can be manipulated from a PC parallel port but you will never get smooth output and you can forget about momentum accelleration. There are also a huge number of Intel-derivative microcontrollers that are as self contained and in much smaller packages then typical motorola parts. I'm most familiar with the Motorola's... For a stepper or waveform output I've always liked the motorola MCUs because they have timer output compare registers that will automatically flip a bit for you on an output port, giving you timer resolution down to crystal / 4 and accuracy that is at the crystal accuracy. But the Intel derivatives are going to be much, much cheaper... $2 or $3 for an MCU that does what you want and extremely easy to program. Look at the MCS51 and MCS96 series. Note that there are dozens of manfacturers of Intel-style controllers. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message