Date: Thu, 11 Jun 1998 16:59:35 +1000 (EST) From: John Birrell <jb@cimlogic.com.au> To: luigi@labinfo.iet.unipi.it (Luigi Rizzo) Cc: mike@smith.net.au, current@FreeBSD.ORG Subject: Re: floating point usage within the kernel - howto ? Message-ID: <199806110659.QAA18095@cimlogic.com.au> In-Reply-To: <199806110443.GAA21849@labinfo.iet.unipi.it> from Luigi Rizzo at "Jun 11, 98 06:43:08 am"
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Luigi Rizzo wrote: > they want to run a P-I-D controller (and more generic controllers > if this goes well) to control a few motors, for didactical purposes. What update rate do they need that requires the code to run in the kernel? > The used to do the same thing under DOS, by hooking this 'real-time' > task to the timer interrupt. I am trying to push them to use FreeBSD > (and an LKM for this module) so that they can easily access the > controller across the network or via the web, use high level stuff > for visualization, etc. I would still do the PID computation in user-space and just use an ioctl to the lkm driver that talks to whatever I/O they have. It would need to be a pretty high speed application to require the code in the kernel and even then it would likely have a dedicated controller anyway. If they want to program like DOS, that's what they should use. 8-) -- John Birrell - jb@cimlogic.com.au; jb@freebsd.org http://www.cimlogic.com.au/ CIMlogic Pty Ltd, GPO Box 117A, Melbourne Vic 3001, Australia +61 418 353 137 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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