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Searching for Android tablet to be used with Parallax products — Parallax Forums

Searching for Android tablet to be used with Parallax products

john_sjohn_s Posts: 369
edited 2013-02-19 23:08 in General Discussion
I'm trying to figure out which A10 / A13 Allwinner chipset based Android tablet would be a good candidate for a test platform to interface with BS2 and Propeller projects.

One requirement is that it has to have a built-in quad-band support for 3G: WCDMA:850/900/1800/1900/2100MHz (and EVDO:800MHz).

something like this one:

http://www.aliexpress.com/store/product/Free-shipping-F8S-3G-phone-call-7-inch-Capacitive-Screen-android-2-3-512MB-4GB-HDMI/403922_543879626.html

Any comments / ideas?

Thanks,
John

Comments

  • prof_brainoprof_braino Posts: 4,313
    edited 2013-02-13 09:51
    We're found that any android device that supports a terminal program can talk to the prop running propforth. I typically use a tablet to run a terminal wireless session to a prop connected to PC by USB serial.

    We also use Bluetooth devices to talks to props with HC05. All we do is change the serial connection pin assignments from pins 30&31 to pins 24&25 where the HC05 is.

    In the above cases, I've used android 2.3 Nook Simple Touch, (Ethernet not Bluetooth) and Samsung Captivate (Bluetooth and Ethernet) up to 4.1 on Nexus 10 (Bluetooth and Ethernet).

    We are also working on an android app which seems to need Android 3.2 or above (for the web stuff), but this is still in development. When complete, it should allow programmable macros associated with touch screen "buttons".

    All this is built one the text - command line interface to propforth, so it may or may not be what you can use. But is you go the text command route, it can be made to work on just about any android device.
  • john_sjohn_s Posts: 369
    edited 2013-02-13 10:35
    Thanks prof - I figure there must a plethora of low end 7" tablets with some exotic brand names available after CES 2013.

    I'd like to hear from our Chinese / Taiwan folks on their experience and suggestions in regard to allwinner based tablets with built-in phone support.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-02-14 04:17
    If you find it difficult to locate a tablet that provides a USB serial port inside Android, any Allwinner A10 that has the USB port might be a candidate to reload with Ubuntu Linux.

    I am somewhat wary of hacking into Android or being dependent on the Apps store for good development tools. But I have compiled Allwinner A10 code from scratch on a 64bit Intel machine and loaded it into a Cubieboard with an A10. The A13 is somewhat more limited in resources, so be careful if you really decide to go with an A13.

    As it is, I can use an Android OS on the Cubieboard and the Ubuntu Linux (which is loaded via an SDcard). This device doesn't have a touchscreen and would be prohibitively costly to add one, but it is a great platform to work with generalized A10 development.

    I had to wait a bit of time for deliver, but I now see they have stock on hand and this is more capable than a Raspberry Pi as it actually has a SATA hard disk interface and a IR remote control receiver.

    http://cubieboard.org/
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-02-14 04:34
    Ummm... It appears that Android Terminal emulator is all you need ... if you have the right Android device.

    And it appears that my dear Cubieboard is once again sold out.

    So go here and read up on what devices might be appropriate. They also suggest installing Busybox, which is a very handy set of Linux utilities, but they don't exactly explain where to get a good A10 image or how to load. You might have to compile your own Busybox to accomodate space limitations from source code.

    https://play.google.com/store/apps/details?id=jackpal.androidterm&hl=en
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-02-14 04:54
    i am wrong again, there is BusyBox help and you need Android 2.3 or more recent.

    https://github.com/jackpal/Android-Terminal-Emulator/wiki/Installing-BusyBox-and-ssh-without-Rooting-your-Device
  • john_sjohn_s Posts: 369
    edited 2013-02-14 07:34
    Thanks Loopy for your very informative reply. I plan to stay with A10 based Android tablet and continue my search for the hackable one :-)

    When you've mentioned a limitation of A13- was it just its limited video support?
    According to some sources the A13 is supposed to be a tad faster and at the same time approx.40% less power hungry.

    What about tablets with built-in 3G support - did you come across a suitable model that you see as a good platform for experimenting further...?
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-02-14 07:53
    I think you should just read the Allwinner's site explanation of the differences between the A10 and the A13, or the Wiki.. wherever that is. You are only going to get a clear idea from the chip manufacturer's documents.

    The above phone doesn't seem to have a USB port, you would have to hack into a wireless interface, likely Bluetooth, to get terminal to work with a Propeller or a BS2. The lack of a USB port is highly likely with all of these... so take a good look at Bluetooth to RS232 interfaces to fill the gap.

    I really like the idea of using the tablet with Android Terminal Emulator, but read all the problems with having to input ESC characters. You may just have a keyboard style interface and not be able to use some buttons or controls as you hope for.

    You are expecting a bit much to find built-in 3G support, a low price, and a useful USB port. The powers that be just don't put USB ports on 3G telephones, at least not on cheap ones.

    I fear you have to use Bluetooth or nothing at all.
    I have seriously done my best to ignore 3G phones here in Taiwan as I pay a mere $6.66 per month for my old clunker and the service fees for 3G are much higher. Also, I don't own a tablet as I don't like smudges all over my display. I am an extremely loyal notebook computer user. And I have done the utmost to ignore Android up until I got the Cubieboard in December as I love Linux.

    But I must say that your inquiry is softening my rather extreme bias as I can see a way into using this user interface.
  • john_sjohn_s Posts: 369
    edited 2013-02-14 12:12
    It's gonna be my first jump into a tablet arena as well so I share your sentiments to "real" keyboard based gadgets :-)
  • john_sjohn_s Posts: 369
    edited 2013-02-16 10:40
    Loopy Byteloose wrote: »
    ... The A13 is somewhat more limited in resources, so be careful if you really decide to go with an A13.


    http://cubieboard.org/

    I found this explanation http://www.spemall.com/blog/?p=821

    "...Allwinner A13 is the cost down version of Allwinner A10, compared to Allwinner A10, A13 is mainly targeted the low-end tablet PC market. In order to save cost, the A13 removed the HDMI and Bluetooth module, and it’s also said that the screen resolution will also change to 800*600, or 800*480..."

    Does that imply that a Bluetooth dongle attached to A13 tablet's USB port won't work at all?
  • TorTor Posts: 2,010
    edited 2013-02-16 11:37
    A bluetooth USB dongle should work if there's a kernel driver for it (and fortunately Bluetooth chipsets mostly "just work" with Linux kernels, which should include Android kernels). So a USB bluetooth dongle should work, provided there's a BT driver. Which there may not be, of course - but at least for 3party Android distros it's reasonably simple to build additional drivers, at least I think so.
    What the A10 has, as have most ARM chipsets, is built-in BT hardware. So you won't need a BT dongle for those. The only problem with that is that as most Android devices have this built-in ARM chipset BT hardware there may not actually be many Android kernels out there with the USB dongle BT driver available, so that's the possible issue here.

    -Tor
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-02-16 22:11
    Beware. If you want to use nearly all the communications features of an A10, you might be limited by the tablet telphone format. The manufacturers seem to not want some items included.. mostly USB ports. On the other hand, it is easy to get most features without the touchscreen in a Cubieboard, but adding the touchscreen to a Cubieboard is expensive and will never be as small and compact as a tablet.

    So reading specifications then expecting to get all deployed in one device and cheaply is just not going to happen.

    I am curious if you want the 3G phone service to be linked to the Android Terminal emulation and then to go into the Bluetooth. I suspect that would not work as there might be parts of the Android OS that are just out of bounds to you. Loading Linux as root might be doable, but the drivers for 3G service may be non-existent proprietary code.

    If I were to buy a 3G Tablet with Android, I would expect to mostly use it as it was intended and consider the hacking with Android Terminal as an interesting additional benefit that is likely to demonstrate some proprietary boundaries. I went with the Cubieboard just to have Linux in an A10 as it is a wonderful small, extremely low power device that can sit on a network 24/7 with a SATA hard disk and be a Linux server. Why bother with running 300 or more watts, when this can do it for so much less? Ane with a much smaller footprint.

    The Raspberry Pi can do a lot, but it is less than the Cubieboard. There are also the Beagleboard, the Pandaboard, and the Beaglebone.
  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-02-17 23:38
    Im sorry if you are wanting a wireless solution only and I missed that to tired to read the whole post. You have the option of using the Android ADK which is on any device running android ICS or higher, my 50 dollar uniden has ICS, basically any newer tab should have ADK support. This alows you to use the USB port to communicate with microcontroller and whatever else. Arduino has an android ADK board, all it is is a mega with a max usb chip on it. I have that same chip on a breakout board, which could be connected to a prop and viola you can speak to android, alot faster too than bt wireless, full usb speeds i belive. FTDI makes a usb host chip specifically for micro to android adk communication, i dont remmber the name but search ftdis site theres a dev board for maybe 30 bucks.

    As i said im sorry if you were looking for wireless solutions only, but as loopy said BT will work. These chips would allow alot more though, maybe you want to funnel camera data to the prop etc.. then check in to usb host solutions. I dont know all the details as i havent had any time to learn how to use the android ADK, but im betting the FTDI data sheets would be a good start, or the Arduino ADK schematics/firmware.
  • john_sjohn_s Posts: 369
    edited 2013-02-19 08:05
    @Tor; Loopy; rwgast

    Thank you all - it seems quite reassuring the BT option is a way to go and should work as expected.
    Time to start searching for specifics of the ADK support...
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-02-19 23:08
    Another thread cropped up with Ubuntu announcing specific support for Touchpads, that means A10 and A13 support is going to improve for Linux.

    You may start out with Android and I do think that is the wisest way to go, but the choices of software may shift in favor of using Ubuntu Linux.
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