From: akropel1@rochester.rr.com (Adam Kropelin)
To: Greg KH <greg@kroah.com>
Cc: Pavel Machek <pavel@ucw.cz>,
linux-kernel@vger.kernel.org, sensors@stimpy.netroedge.com
Subject: [PATCH] I2C update for 2.6.8-rc1
Date: Thu, 19 May 2005 06:25:06 +0000 [thread overview]
Message-ID: <20040716141939.B8270@mail.kroptech.com> (raw)
In-Reply-To: <20040716171702.GA10598@kroah.com>; from greg@kroah.com on Fri, Jul 16, 2004 at 10:17:03AM -0700
On Fri, Jul 16, 2004 at 10:17:03AM -0700, Greg KH wrote:
> On Fri, Jul 16, 2004 at 07:07:16PM +0200, Pavel Machek wrote:
> > Hi!
> >
> > > +menu "Dallas's 1-wire bus"
> > > +
> > > +config W1
> > > + tristate "Dallas's 1-wire support"
> > > + ---help---
> > > + Dallas's 1-wire bus is usefull to connect slow 1-pin devices
> > > + such as iButtons and thermal sensors.
> >
> > Just out of curiosity... are such devices really connected using one wire only,
> > or is it GND+5V+one data wire, or GND+power&data wire?
>
> I'm pretty sure it's just 1 wire, at least for the devices I've seen.
It's GND+power&data. The device derives its power from transitions on
the data line driven by the master. Consequently there are some fairly
strict timing requirements on those pulses. Some devices can also be
powered by a dedicated VCC line which generally allows the device to
respond faster. A temperature sensor IC, for example, can usually
complete a conversion cycle much faster when it has dedicated power.
--Adam
WARNING: multiple messages have this Message-ID (diff)
From: Adam Kropelin <akropel1@rochester.rr.com>
To: Greg KH <greg@kroah.com>
Cc: Pavel Machek <pavel@ucw.cz>,
linux-kernel@vger.kernel.org, sensors@stimpy.netroedge.com
Subject: Re: [PATCH] I2C update for 2.6.8-rc1
Date: Fri, 16 Jul 2004 14:19:39 -0400 [thread overview]
Message-ID: <20040716141939.B8270@mail.kroptech.com> (raw)
In-Reply-To: <20040716171702.GA10598@kroah.com>; from greg@kroah.com on Fri, Jul 16, 2004 at 10:17:03AM -0700
On Fri, Jul 16, 2004 at 10:17:03AM -0700, Greg KH wrote:
> On Fri, Jul 16, 2004 at 07:07:16PM +0200, Pavel Machek wrote:
> > Hi!
> >
> > > +menu "Dallas's 1-wire bus"
> > > +
> > > +config W1
> > > + tristate "Dallas's 1-wire support"
> > > + ---help---
> > > + Dallas's 1-wire bus is usefull to connect slow 1-pin devices
> > > + such as iButtons and thermal sensors.
> >
> > Just out of curiosity... are such devices really connected using one wire only,
> > or is it GND+5V+one data wire, or GND+power&data wire?
>
> I'm pretty sure it's just 1 wire, at least for the devices I've seen.
It's GND+power&data. The device derives its power from transitions on
the data line driven by the master. Consequently there are some fairly
strict timing requirements on those pulses. Some devices can also be
powered by a dedicated VCC line which generally allows the device to
respond faster. A temperature sensor IC, for example, can usually
complete a conversion cycle much faster when it has dedicated power.
--Adam
next prev parent reply other threads:[~2005-05-19 6:25 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-15 0:05 [BK PATCH] I2C update for 2.6.8-rc1 Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` [PATCH] " Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-15 0:07 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-16 17:07 ` Pavel Machek
2005-05-19 6:25 ` Pavel Machek
2004-07-16 17:17 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-07-16 17:39 ` Bob Riegelmann
2005-05-19 6:25 ` Bob Riegelmann
2004-07-16 18:19 ` Adam Kropelin [this message]
2005-05-19 6:25 ` Adam Kropelin
2005-05-19 6:25 ` Greg KH
2005-05-19 6:25 ` Greg KH
2005-05-19 6:25 ` Jean Delvare
2005-05-19 6:25 ` Philip Pokorny
2004-07-17 14:30 ` Greg (or anyone else) one small i2c question Reinder
2004-07-30 5:40 ` --- " Reinder
2004-07-30 6:30 ` Denis Vlasenko
2004-08-25 6:44 ` Greg " Greg KH
2004-08-24 21:58 ` [BK PATCH] I2C update for 2.6.8-rc1 Alex Williamson
2005-05-19 6:25 ` Alex Williamson
2004-08-24 22:04 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-08-25 0:37 ` Linus Torvalds
2005-05-19 6:25 ` Linus Torvalds
2004-08-25 1:38 ` Alex Williamson
2005-05-19 6:25 ` Alex Williamson
2004-08-25 1:42 ` Alex Williamson
2005-05-19 6:25 ` Alex Williamson
2004-08-25 2:02 ` Linus Torvalds
2005-05-19 6:25 ` Linus Torvalds
2004-08-25 6:14 ` Greg KH
2005-05-19 6:25 ` Greg KH
2004-08-25 6:36 ` Greg KH
2005-05-19 6:25 ` Greg KH
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