Date: Sun, 27 Oct 2002 20:51:05 +0100 From: Wilko Bulte <wkb@freebie.xs4all.nl> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: David Nicholas Kayal <davek@saturn5.com>, nbari@unixmexico.com, freebsd-hackers@FreeBSD.ORG Subject: Re: i am looking for a 5 volt signal Message-ID: <20021027205105.A822@freebie.xs4all.nl> In-Reply-To: <200210271919.g9RJJFEm091313@apollo.backplane.com>; from dillon@apollo.backplane.com on Sun, Oct 27, 2002 at 11:19:15AM -0800 References: <Pine.BSF.4.44.0210270918380.364-100000@blackbox.yayproductions.com> <200210271919.g9RJJFEm091313@apollo.backplane.com>
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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
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