Date: Tue, 15 Sep 2009 01:04:38 -0700 From: perryh@pluto.rain.com To: rsmith@xs4all.nl Cc: freebsd-questions@freebsd.org Subject: Re: rebinding keys to functions Message-ID: <4aaf4a96.rnIcIpF47vYAtgHm%perryh@pluto.rain.com> In-Reply-To: <20090914224038.GA77585@slackbox.xs4all.nl> References: <a0777e080909140952r18cc88b3n2b3ff1456c2542c7@mail.gmail.com> <20090914173420.GB69286@slackbox.xs4all.nl> <19118.36021.489954.856994@jerusalem.litteratus.org> <20090914230620.2f7dd3d4.freebsd@edvax.de> <20090914224038.GA77585@slackbox.xs4all.nl>
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Roland Smith <rsmith@xs4all.nl> wrote: > Writing a driver to detect if headphones are connected sounds > much more complicated to me than connecting a couple of switches! > I mean, you'd have to measure something like the impedance of > the jack. Surely that is more expensive than a simple switch? Or use a simpler jack, with one switch that connects to ground or not depending on whether the plug is inserted or not. It probably costs a cent or two less than the usual two-switch variety, and this is a BOM (Bill Of Materials, i.e. per-unit-built) savings. Writing the driver is an NRE (non-recurring engineering) expense which can be amortized over -- the manufacturer hopes -- a huge number of delivered units.
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