SD format Zigbee card ...

Kristoffer Ericson kristoffer.ericson at gmail.com
Sat Dec 5 08:44:17 EST 2009


On Fri, 4 Dec 2009 21:33:25 -0500
Wolfgang Spraul <wolfgang at sharism.cc> wrote:

> Rakshat,
> 
> > I am just thinking aloud but it may be better to wait for a nanonote with
> > USB Host (Ya?) to easily use ZigBee USB dongels than put in effort into
> > supporting microSD ZigBee for Ben only.
> 
> I know everybody thinks about "USB Host" as the very first thing.
> However, the longer we don't have it the more I like that Ben NanoNote has
> no USB Host :-)
> 
> You may know that we have a few (9 to be precise) prototype boards that
> actually have USB Host _TODAY_ (if anybody wants to buy them please contact
> Mirko at mirko at qi-hardware.com).
> However, I do think this is only good for development use. Someone could
> attach a u-blox GPS USB dongle and start working on a great openstreetmap
> application today.
> 2 of these boards are currently on the way to Carlos, let's see what he
> does with them :-)
> 
> USB Host has two major problems in mobile use:
> 
> Anything you really connect to a USB Host plug will be BIG! If it's a
> dongle, it may be so big that the connector inside the device can easily
> break off.
> If you first connect a cable, reducing the risk of mechanical damage to
> the NanoNote, you are talking about a really geeky setup. Our cute and
> tiny NanoNote in your hand, then a cable, then a dongle.

As an "experienced" handheld user/softdeveloper (jornada 600/700/Zaurus spitz/nec mobilpro/ipaq)
I just want to say that I fully agree with Wolfgang in this. You always get a false feeling with
usb adapters that they will fix everything, usually you end up avoiding to use them since
the earlier easy to carry/use device ends up being a battery hog and looks dead ugly.

Something that fits into an slot (and therefore not "extends" the device) is always a good thing.

> 
> Next problem: power consumption. USB Host specifies 5V. 5V is a lot,
> both inside the device and for most things you connect outside the voltage
> will be less. So on our USB Host enabled boards, we had to add a voltage
> converter from 3.3V to 5V just for USB Host. And then inside the dongle
> it needs to be converted down again. The conversions are lossy (energy
> is lost), and the chips that convert up and down are expensive.
> Compare that to SDIO voltage which is 3.3V.
> 
> Bottom line - if you had a NanoNote with both SDIO and USB Host today, and
> both the microSD Wi-FI card and USB Host Wi-Fi dongle would be available, I
> guarantee you you would choose the microSD card. It's so small you can
> actually leave it in your device. If you had multiple (like Wi-Fi + ZigBee),
> you could tape them to the back of the device, or store under the battery cover
> maybe :-) That's how small they are...
> Power consumption will be much better with the microSD SDIO solution than
> anything you connect to USB Host. 
> 
> So let's see. I am excited to see some microSD RF solutions on the horizon
> (Wi-Fi and maybe ZigBee).
> But before we get too excited - there is still _LOTS_ of work to make it
> REALLY USEFUL for someone. Not just theoretically.
> Let's try to get all that hard work done first, then we see in which cases
> we can recommend, and sell, these solutions. If we say it really works, it
> better actually work and not have some stupid surprise once you start
> using it.
> Same for USB Host. We have some prototype boards today. They were very
> expensive to make but we did it. We can now jumpstart development of some
> apps or hardware hacks, then we need to think how we can integrate this
> into Ya to make an actual end user package out of it.
> Ya will probably have a micro-AB USB Host connector, and future devices
> will have USB On-The-Go as well, but how useful that will be for normal
> users (as opposed to developers) remains to be seen...
> 
> Just my thinking, feedback very welcome,
> Wolfgang
> 
> On Fri, Dec 04, 2009 at 11:55:57PM +0530, rakshat hooja wrote:
> > >
> > > What should we do? If you are interested in some ZigBee hacking, I can put
> > > a package together for you. You would probably need at least one NanoNote,
> > > and 2 ZigBee cards?
> > > I guess I would have to buy the 1000 USD devkit.
> > > What do you think? Is anybody else interested in ZigBee? Can you or someone
> > > else share some of the costs?
> > > Is there another microSD ZigBee card with already proven Linux support?
> > >
> > > Hope this helps, let me know what you want to do,
> > >
> > >
> > 
> > 
> > I am just thinking aloud but it may be better to wait for a nanonote with
> > USB Host (Ya?) to easily use ZigBee USB dongels than put in effort into
> > supporting microSD ZigBee for Ben only.
> > 
> > I have copied Ranjan on this mail - He was planning to use ZigBee with the
> > Freerunner for an home automation system (see
> > http://www.youtube.com/watch?v=zZuR1yE9A40  ) and may have more info about
> > linux drivers for ZigBee USB dongles
> > 
> > Rakshat
> 
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> 
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-- 
Kristoffer Ericson <kristoffer.ericson at gmail.com>




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