Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Commits on Jun 18, 2012
Commits on Aug 16, 2011
  1. Lots of changes for migrating from 1-Wire® over to Fox-Bus™.

    authored
    These changes are not complete, but in light of some recent
    developments I felt it was necessary to update the documentation
    of this project as soon as possible.
    
    It turns out that MAXIM is unable or unwilling to offer any
    license for the 1-Wire® slave protocol on a non-MAXIM IC.
    As a result of this revelation, a suitable alternative
    to the 1-Wire protocol must be found and used instead.
    
    For now, I have settled on Fox-Bus™, which has been developed
    by Chris Fox. This protocol is a free single-wire alternative
    to 1-Wire, and Chris is generously allowing this project
    to take advantage of his research to use his protocol.
    
    Chris has indicated that he intends to make more information
    available at <http://fox-bus.com/> in the near future.
    
    For historical purposes, below is the email exchange between
    MAXIM and myself. Note that MAXIM is simply asserting their
    right to not license their patent. While I may find patents
    like this one to be rather dubious, I respect the fact that
    this is their right---and you should too. Do not harass MAXIM
    about this subject, as doing so would be counter-productive.
    Besides, there are alternatives that are better than the
    1-wire protocol for this application.
    
    Begin forwarded message:
    
    > From: Hal Kurkowski <Hal.Kurkowski@maxim-ic.com>
    > Date: August 10, 2011 12:34:12 PM PDT
    > To: Robert Quattlebaum <darco@deepdarc.com>
    > Cc: Scott Jones <Scott.Jones@maxim-ic.com>
    > Subject: RE: 1-wire license agreement
    > 
    > Robert,
    > 
    > Thanks for your email.
    > 
    > In response to your questions:
    >
    >> 1) Will you require that I license the 1-wire protocol from you for
    >> devices which I build for my own personal use? (limited to 25 devices,
    >> max)
    >
    > Any non-Maxim slave device that incorporates the 1-Wire protocol
    > would be considered to be in violation of Maxim's applicable 1-Wire IP.
    >
    >> 2) Would the incorporation of a DS2401 into the design implicitly
    >> license the 1-wire patent for the device in the eyes of your legal team?
    >
    > Incorporating a 1-Wire slave device within a system does not allow
    > unlimited use of the protocol by other, non-Maxim parts.
    >
    >> 3) Would Maxim be willing to license the 1-wire patent for devices which
    >> include no Maxim parts?
    >
    > We currently are not able to license you or your company for this
    > application.
    > 
    > Hal Kurkowski
    > Managing Director
    > Maxim Integrated Products
    > 
    > 
    > -----Original Message-----
    > From: Robert Quattlebaum [mailto:darco@deepdarc.com]
    > Sent: Thursday, July 21, 2011 3:46 PM
    > To: Hal Kurkowski
    > Subject: Fwd: 1-wire license agreement
    > 
    > Hello Hal! I was referred to you by Chris Fox, in the email quoted
    > below.
    > 
    > As a hobby project, I have been developing a capacitive soil moisture
    > sensor which utilizes a ATtiny25 microcontroller and a few passive
    > components. I intend to release this project as an "open-source
    > hardware" project, licensed under the CC-BY-SA-3.0 and GPL-2.0
    > licenses. The project is generally documented in the following
    > links:
    > 
    > http://www.deepdarc.com/2010/11/01/soil-moisture-sensor/
    > http://www.deepdarc.com/2011/01/08/soil-moisture-sensor-update/
    > http://www.deepdarc.com/2011/07/20/sensor-panel/
    > https://github.com/darconeous/soil-moisture-sensor/
    > 
    > The use of the 1-wire protocol for communicating with the sensor
    > seemed like a natural fit, as it would allow the sensors to be
    > chained together easily. I was able to implement a 1-wire slave
    > interface in software on the ATtiny25, and it is working great. The
    > only issue is one of the 1-wire patent, which MAXIM owns.
    > 
    > I figured that as long as the device contained at least one official
    > 1-wire component (such as the DS2401) that this may be sufficient
    > (via "patent exhaustion") to cover the entire device, so I adjusted
    > the design of the sensor to include a DS2401. However, I have
    > absolutely no resources to consider an option which might possibly
    > lead to litigation, so I wanted to clarify the issue with you
    > directly.
    > 
    > At this time I am developing these devices for my own personal use,
    > but if there is enough interest I may make a production run of a
    > few thousand, perhaps sold via kickstarter.com. As such I wanted
    > to reach out to you directly to get a feel for what your views are
    > on this subject and to possibly discuss patent licensing options.
    > 
    > Alternatively, I could abandon the 1-wire protocol entirely and use
    > a different non-patented protocol---but I think that using the
    > 1-wire protocol in this case adds significant value to the utility
    > of this product.
    > 
    > So, my questions are as follows:
    > 
    > 1) Will you require that I license the 1-wire protocol from you for
    > devices which I build for my own personal use? (limited to 25
    > devices, max)
    > 2) Would the incorporation of a DS2401 into the design
    > implicitly license the 1-wire patent for the device in the eyes of
    > your legal team?
    > 3) Would Maxim be willing to license the 1-wire
    > patent for devices which include no Maxim parts?
    > 
    > If there are any additional points which come to mind which are not
    > addressed by these questions which you think are relevant to this
    > project, please let me know.
    > 
    > Again, at this point these devices are for my own personal use---I'm
    > just trying to get a feel for what my liabilities are with respect
    > to this project.
    > 
    > Thanks for your time!
Commits on Aug 10, 2011
Commits on Aug 8, 2011
  1. Updated the notes.

    authored
Commits on Aug 7, 2011
Commits on Jul 27, 2011
Commits on Jul 23, 2011
  1. General refactoring.

    authored
    Now fits on the ATtiny13A again. Minor protocol changes.
Commits on Jul 17, 2011
  1. More updates.

    authored
Commits on Jul 14, 2011
  1. Uncrustify.

    authored
Commits on Jul 12, 2011
  1. Lots of updates leading up to v1.0 release.

    authored
    This is the cumulation of many commits I've made to my own sandbox,
    and I think it's about time I push these to the main branch.
Commits on Jun 30, 2011
Commits on Jun 29, 2011
Commits on Jun 28, 2011
  1. Added Gerber files.

    authored
Commits on Jun 25, 2011
  1. Minor updates and cleanups.

    authored
Commits on Jun 24, 2011
Commits on Jun 23, 2011
  1. First working version.

    authored
    I can now enumerate the sensor as a 1-wire device and read
    out the soil moisture. Works with several 1-wire devices
    on the same bus. Still need to work out the exact protocol,
    but so far so good.
    
    Also adjusted the PCB design to take into account some
    lessons learned. Turns out just having one big sensor
    plane without a ground plane wasn't such a good idea after
    all.
Commits on Jun 21, 2011
  1. Initial work on wire protocol for reading soil moisture. Untested.

    authored
    This is me wrapping up several commits from last weekend.
Commits on Jun 19, 2011
Commits on Jan 10, 2011
  1. initial version

    authored
    git-svn-id: http://svn.deepdarc.com/code/soil-moisture-sensor/trunk@1010 d48f582a-3cf3-0310-b784-83b2ddae21dc
Something went wrong with that request. Please try again.