Ya: backlit keyboard - Rii Mini case study

Ron K. Jeffries rjeffries at gmail.com
Tue Jul 13 13:25:12 EDT 2010


Very interesting set of references, thanks.

Let's assume a future Nanonote includes
an ISM radio such as HopeRF or others.

One can do MANY of clever things with that,
but using the Internet at a public hot spot isn't one of them.

So...

Copyleft and open? Yes!
Able to use the internet without being tethered? NO.

Ben Nanonote sans direct Ethernet is a cool
device that almost 1000 people have purchased

What I don't understand is how/why purity
of the copyleft philosophy trumps having a highly
desirable capability -- untethered internet access

please don't shoot the messenger. just sayin' ;)
---
Ron K. Jeffries
http://ronkjeffries.posterous.com









On Tue, Jul 13, 2010 at 09:39, Werner Almesberger <werner at openmoko.org> wrote:
> Wolfgang Spraul wrote:
>> good to see how others solved the backlight problem.
>
> I was afraid that there would be just a few LEDs but a lot of
> "fancy plastic" to distribute the light. It's nice that what
> seems to be a much more pedestrian approach works so well.
>
>> Does this have anything to do with 'USB'? First time I hear about WirelessUSB.
>> Wikipedia says WirelessUSB operates at 3.1 to 10.6 GHz, but the Cypress chip
>> talks about 2.4 GHz?
>> http://en.wikipedia.org/wiki/Wirelessusb
>
> The difference may be in the space between "Wireless" and "USB".
> Without it, it's Cypress' 2.4 GHz stuff, about which they proudly
> proclaim:
>
> | WirelessUSB and enCoRe are trademarks of Cypress Semiconductor.
>
> The Wiki page says that USB-IF prefers people to call theirs
> somewhat pompously "Certified Wireless USB". I guess now we know
> why :-)
>
> A good comparison:
> http://www.ac.tut.fi/aci/courses/ACI-31070/pdf/UWB WUSB WirelessUSB.pdf
>
>> Maybe to look at RF in Ya, we should first identify some interesting, free
>> software / GPL licensed stacks? Then find a matching module/RF IC for it?
>
> I'm still not sure what would be the best strategy. I've tried a
> search for standards (see below) but I'm not entirely happy with
> the results. I've now started to look at what the major chip
> makers have to offer.
>
>> Are you aware of any good and stable RF protocol stacks implemented in
>> free software?
>
> Nothing interesting beyond things that have already been mentioned.
> I would in fact go one step back and look for Open standards, not
> necessarily implementations.
>
> Here's a very rough compilation of things I found so far for the
> ISM bands that aren't flat out "vendor standards":
>
>                Band    Rb      Range Modulation Openness/Patents       Ref.
>                434 915 kbps    m                Standard       Use
>                | 868 2.4       (nom)
>                | | | |
> Bluetooth
>  Wibree        - - - x    1000  10   ?          "open"         ?       [8]
> IEEE 802.15.4   - x x x  20-250   ?   many       open [11]      ?       [11]
>  6LoWPAN       n/a      n/a    n/a   n/a        open [10]      open?   [9]
>  MiWi          - - - x    -250   ?   ?          unpublished    ?       [13]
>  WirelessHART  - - - x    ?      ?   QPSK       for-pay        roylty-free [14]
>  ZigBee        - - - x 250-500  75   QPSK                              [1]
> INSTEON         - - x -    ?     50   FSK        for-pay?       ?       [12]
> ISO/IEC 18000-7                                  for-pay?       RAND    [2]
>  DASH7         x - - -  28-100 250   FSK,GFSK   =              =       [1]
> ONE-NET         ? x x ?    ?     ?    FSK        ?              roylty-free [7]
> Wavenis         x x x -   5-100 100+  ?          ?              ?       [4]
> UWB
>  Wireless USB  > 3 GHz  53-480  10   MD-OFDM    open [6]       ?       [5]
> Z-Wave          - x x -  10- 40  30   GFSK       NDA            ?       [3]
>
> [1] http://www.dash7.org/DASH7%20WP%20ed1.pdf
> [2] http://www.dash7.org/index.php?option=com_content&view=article&id=13&Itemid=15
>    http://www.savi.com/partners/licensees/index.php
>    http://www.savi.com/partners/licensees/iso-18000-7.php
> [3] http://en.wikipedia.org/wiki/Z-wave
> [4] http://en.wikipedia.org/wiki/Wavenis
> [5] http://en.wikipedia.org/wiki/Wireless_USB
> [6] http://www.usb.org/developers/wusb/wusb_2007_0214.zip
> [7] http://en.wikipedia.org/wiki/ONE-NET
>    http://one-net.info/
>    (Site requires registration and moderator approval to even read any
>    technical information.)
>    http://www.one-net.info/index.php?option=com_content&view=category&layout=blog&id=2&Itemid=3
> [8] http://en.wikipedia.org/wiki/Wibree
> [9] http://en.wikipedia.org/wiki/6LoWPAN
> [10] http://tools.ietf.org/html/rfc4944
> [11] http://en.wikipedia.org/wiki/IEEE_802.15.4
>     (links to IEEE standard documents, with click-through license)
>     note: 802.15.4-2006 specifies ASK for 868/915 but requires devices to also
>     implement QPSK.
> [12] http://en.wikipedia.org/wiki/INSTEON
> [13] http://en.wikipedia.org/wiki/MiWi
>     http://ww1.microchip.com/downloads/en/AppNotes/MiWi Application Note_AN1066.pdf
>     Implementation tied to use of Microchip products. No indication about IP
>     in protocol.
> [14] http://en.wikipedia.org/wiki/WirelessHART
>     http://www.hartcomm.org/hcf/documents/documents_specifications.html
>
> - Werner
>
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