From owner-freebsd-hackers Sun Oct 27 11:51:17 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B002337B401 for ; Sun, 27 Oct 2002 11:51:15 -0800 (PST) Received: from freebie.xs4all.nl (freebie.xs4all.nl [213.84.32.253]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1BC7743E3B for ; Sun, 27 Oct 2002 11:51:14 -0800 (PST) (envelope-from wkb@freebie.xs4all.nl) Received: from freebie.xs4all.nl (localhost [127.0.0.1]) by freebie.xs4all.nl (8.12.6/8.12.6) with ESMTP id g9RJp6Nb000840; Sun, 27 Oct 2002 20:51:06 +0100 (CET) (envelope-from wkb@freebie.xs4all.nl) Received: (from wkb@localhost) by freebie.xs4all.nl (8.12.6/8.12.6/Submit) id g9RJp6sT000839; Sun, 27 Oct 2002 20:51:06 +0100 (CET) Date: Sun, 27 Oct 2002 20:51:05 +0100 From: Wilko Bulte To: Matthew Dillon Cc: David Nicholas Kayal , nbari@unixmexico.com, freebsd-hackers@FreeBSD.ORG Subject: Re: i am looking for a 5 volt signal Message-ID: <20021027205105.A822@freebie.xs4all.nl> References: <200210271919.g9RJJFEm091313@apollo.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200210271919.g9RJJFEm091313@apollo.backplane.com>; from dillon@apollo.backplane.com on Sun, Oct 27, 2002 at 11:19:15AM -0800 X-OS: FreeBSD 4.7-RC X-PGP: finger wilko@freebsd.org 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 Sun, Oct 27, 2002 at 11:19:15AM -0800, Matthew Dillon wrote: > > : > :Shouldn't the fact that the signal is in a while loop keep the 5 volt > :signal going? Isn't the parallel port being blasted with the > :value 255 over and over again? > : > :The serial port will not fulfill what i am ultimately trying to achive. I > :am trying to have the parallel port to control 8 relays each turing > :on/off based upon which bit i send out to the port. > : > :.. > :> try using also the serial port and a logical buffer > :> > :> the 5 volt signal is very fast and your multimeter is maybe not to fast > :> > :> > I'm looking for a 5 volt signal. > > Uh guys. Parallel port digital outputs do not generally have a whole > lot of drive. I really doubt a parallel port output could drive a > relay. Get a solid state relay. Parallel ports used to be build with TTL chips, but these days drive power is probably much less. > And it's probably TTL level equivalents, not CMOS. Even if you ganged > the output bits together I doubt you would get enough drive out of > them. Yup. -- | / o / /_ _ wilko@FreeBSD.org |/|/ / / /( (_) Bulte Arnhem, the Netherlands To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message