[Commotion-dev] Android stick-PCs as a potential Commotion/FreedomBox/OpenWRT platform?

Wed Apr 24 23:48:06 UTC 2013

Hello,

The question of ad-hoc mode remains unanswered on the MK808B that we have
here.
As mentioned, it should be possible with some work, due to the use of a
broadcom 4330 chipset.
It is a public holiday here, so I can't try getting ad-hoc on it right now.

However, as I mentioned, I think a good longer-term strategy would be to
work with one of the suppliers to make one using an atheros wi-fi chipset,
so that we have the same happy goodness as on many of the OpenWRT devices
-- but at the attractive price-point of these stick PCs.

Also, getting power consumption down to ~1W makes a big difference for
rechargeable/solar deployments, which I think will be important for both
Commotion and Serval.

Paul.

On Thu, Apr 25, 2013 at 7:45 AM, Hans of Guardian <hans at guardianproject.info
> wrote:

>
> They're available for about US$40-70 on amazon:
> http://www.amazon.com/MK808-Android-Rockchip-RK3066-Cortex-A9/dp/B009OX22B4
>
> http://www.amazon.com/Android-Smart-internet-adaptor-dongle/dp/B009F8HS4E/ref=sr_1_4?s=electronics&ie=UTF8&qid=1366841516&sr=1-4&keywords=ug802
>
> The have much faster CPUs that are also dual core.  They include 4GB
> storage and have a micro-sd slot and USB.  They are also ready to go with
> Android and the Play Store installed.  I think they are probably a better
> deal than the RPi for working with wifi.  Attach an external USB wifi, and
> you have a two radio device.
>
> But this is all contingent on having decent adhoc support in the radio, of
> course.
>
> .hc
>
> On Apr 24, 2013, at 6:07 PM, Dan Staples wrote:
>
>  The Android sticks certainly do make a tempting platform for some
> experimentation. I wonder, however, how they compare in
> capability-versus-price with the Raspberry Pi. An RPi by itself costs
> US$35, and has ethernet, 2 usb, 512MB RAM, 700 MHz single core processor,
> and draws b/w 500-1000 mA @ 5 V (= 2.5-5 W if my physics degree serves me
> well ;) ). Attach to that a dual-antenna Atheros-based USB wifi adapter
> (e.g. http://www.tp-link.com/en/products/details/?model=TL-WN822N), which
> can potentially do multiple virtual interfaces, one in ad-hoc and the other
> in AP mode, and you got yourself a pretty capable gadget.
>
> And at a recent conference, I powered some wifi-enabled, meshing RPis with
> simple battery packs. I've even powered them from 2 D cells with a proper
> voltage converter, which could potentially power a device for more than a
> day.
>
> Just another idea to throw into the mix...  I think experimenting with the
> android sticks is a great idea.
>
> cheers,
> Dan
>
>
> On 04/24/2013 05:28 PM, Paul Gardner-Stephen wrote:
>
> Hi all,
>
>  Sorry if you have already thought about and discussed these devices, but
> they strike me as potentially very interesting for both communities, in
> addition to our own interest in them for the Serval Project.
>
>  We have been looking at some of the cheap Android-based stick PCs as a
> possible platform for Serval Mesh Extenders, such as the MK802ii and more
> recent MK808B.  For more about the Mesh Extenders and their long-range UHF
> packet radios, refer to:
>
>
> http://developer.servalproject.org/dokuwiki/doku.php?id=content:meshhelper:main_page&#prototyping
>
>
>  or:
>
>
> http://servalpaul.blogspot.com/2013/02/building-serval-mesh-helper-device.html
>
>  and subsequent posts to that blog.
>
>  The newer generations of the Android stick-PCs have dual-core 1.5GHz ARM
> processors, 1GB of RAM and 16GB of flash, dual-antenna 802.11n Wi-Fi
> (although the firmware is not ideal, more on that later), USB host port,
> microSD slot, and HDMI out, all in a tiny thing about 80mm x 35mm x 15mm
> depending on the particular variant you get.  You get all that for under
> US$50, e.g., from geekbuying.com.
>
>  These typically come with a root-enabled ROM, and are very easy to flash
> with a complete new operating system.
>
>  Thus compared with many wireless routers they have much greater CPU and
> memory resources, and similar or lower cost.
>
>  What I wanted to discover what their power consumption was, because I
> want to run them off battery for really resilient deployments.
>
>  While I was initially concerned about the power consumption, I
> discovered that the later generation models can perform useful services,
> including running Wi-Fi for about 1W:
>
>
> http://servalpaul.blogspot.com/2013/04/comparing-energy-consumption-of.html
>
>  The main issues that I have identified are likely to be:
>
>  1. The Wi-Fi antenna are little patch antenna, which probably don't have
> that great performance.  They could be replaced fairly easily though, I
> suspect.  On the up-side, they do have two antenna for doing clever 802.11n
> things.
>
>  2. The Wi-Fi firmware that comes with the ROMs I have found don't
> include simultaneous AP and ad-hoc capability, at least as far as I can
> tell.  This would need investigation.  They apparently use a Broadcom 8330
> based Wi-Fi chipset in at least some variants, which leads to my next point.
>
>  3. The Wi-Fi chipset and design quality varies between suppliers of
> these, as it appears that they are all using a reference design of the
> RK3066 chipset, to which they add Wi-Fi.  Some use realtek or mediatek
> chipsets instead of broadcom.  Some implementations are better than others,
> e.g., some sub-optimal implementations seem to have a common ground-plane
> between the Wi-Fi and USB, which reduces the sensitivity of the Wi-Fi
> receiver. All this is both a negative and positive. On the negative side,
> some variants might be complete duds for our desired use-cases.  On the
> positive side, it might be possible to encourage one of these manufacturers
> to make one with, for example, an Atheros Wi-Fi chipset that is well
> supported by Linux, OpenWRT and Debian.  Related, I have yet to survey the
> complete OS image to see if there are any other closed binary blobs hiding
> around the place.
>
>  4. There is no on-board ethernet port on the cheaper models.  This could
> be solved with a USB ethernet adapter, or again, encouraging one of the
> manufacturers to make a variant that is better optimised for our
> communities needs.
>
>  If anyone in the community is interested in working on porting OpenWRT
> and/or enabling simultaneous AP+ad-hoc Wi-Fi on these, we can probably
> arrange to provide a couple of MK808Bs to facilitate this.
>
>  Paul.
>
>
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>
> --
> Dan Staples
>
> Open Technology Institutehttps://commotionwireless.net
>
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