Friday, 1 February 2013

Sabre Lite - DATV-Express - Interesting SDR

I recently purchased from Farnell a Freescale Sabre Lite board (see above).
I removed the supplied OS and now have Linaro Linux running on it.
This has a Quad core ARM processor on it with each core running
at up to 1 GHz. It also has 1 Gb RAM and interestingly a 24 bit RGB input port.
The hardware H.264 encoder will encode 1080P at 30 fps and decode at 60 fps.
I plan eventually to port my DATV code to this and use it in conjunction with a
DATV-Express board as a standalone DATV system. There is no MPEG2 on it
but I understand it is capable of encoding MPEG2 in software in real time using
GStreamer plug ins.

Which nicely takes us on to DATV-Express, the board design files have been sent to
the manufacturer and should be ready on the 21st of February. Then they will need to
be hand populated.

Finally I was made aware of this Kickstarter project  bladeRF which looks very
interesting, it would be fully capable of doing DATV. What makes it interesting is the
LimeMicro LMS6002D chip which integrates the RF, mixers, Anti-alias filters and
ADC/DAC onto one chip and which will operate at up to 3.8 GHz. I am tempted as I
could easily move my DATV code to run on it. I wish them well with the project.
Now if they could only get the price down :)


  1. Hi Charles - good news on the DATV express boards - can't wait to get my hands on one.
    Also interested to read about your experiments on the Sabre board. Really want to making it as standalone as possible for /P operation.
    But guess this will still need some external hardware to decode a PAL signal to the rgb input and something else for the sound
    Still like the idea of using a RPi - if only to play out pre recorded clips from an SD card.
    As for Blade - well one thing at a time - at least DATV Express is about to come to fruition whereas the Blade is still largely vapourware at this stage.
    Keep up the good work - 73. Ian

  2. Hello Ian,
    The way I look at it is that if the software
    is written in a portable way for the host it
    should run on just about anything.

    To me bladeRF is just another HW device and
    with a driver will work with the DATV-Express
    host software.

    As far as the Pi is concerned if you are happy
    with the quality of the Webcam they are going
    to sell you should be fine.

    Analog devices seem to do a 100 pin chip that
    will input RGB/composite/component and output
    in RGB24 format so yes another board would be
    required by AD have done the hardwork! Maybe a
    little project for someone :)

    - Charles

  3. Hello Charles,

    I have a Pi on order and have not yet researched the video processing options. Am I correct in that a webcam may be available that will connect directly to the Pi allowing that configuation to serve as the video front end and taking the place of the Hauppauge PVR 500/150 as described in the TAPR ppt presentation?

    Mike KM7MH

  4. Yes you are correct, the GPU in the PI does H.264 encoding
    rather than MPEG2. Over here most DATV is MPEG2. The Raspberry
    PI OS support is fairly rudimentary at the moment but people
    are working on it so things will improve. There are plenty
    of other uses around the shack so I think you will be pleased
    with your purchase.

  5. I believe all of the sat receivers decode H.264, that's great. I'm still in the shrink it down mode for a radio controlled aircraft where encoding format will not be an issue.

    What is the current and voltage requirement for the DATV-Express?

    I was on the Hauppauge website and saw the HD PVR. Is this an option for HD with the DATV-Express? It's H.264 so, compatibility issues with MPEG2 repeaters again. Good for point to point link though.

    Mike KM7MH

  6. You will need to use an HD sat receiver to decode h.264.
    DATV Express needs between 10 and 15 volts. Current wise I am
    not sure but the chip that gets the hottest uses about 400 mW
    so you should be able to get away with about 1oo mA but have not
    measured it. My current Linux code can use the PVR-HD.

    - Charles

  7. I've been playing with free to air satellite for several years and have been through many receivers. This is the one I'm using presently, best ever. Decodes everything and pulls channels out of blind search that no others can, incredibly small too.

    Mike KM7MH