DATV Express Early Tests

[G8DKC]

Hi Charles,

I see we have a forum!
The last few days,
Have found a used quad core Tower at a good price and fighting with Win7 64bit Os the usual driver problems!
Tutioune now working, Hauppauge 150 yet to install, may have to look for HVR type card, Hi.
Still the same issue with Ver 2.02, but will try Tower Pc to compare.
As for v4l2-ctl commands at pc startup.
I'm finding that they do not work until DVB Tx started as v4l2-ctl can't see the hardware,
and then you may have to send twice from Terminal.

I have the same setup as Ken has shown, with dir-coupler and R-DSA815, but all in coax with attenuators to Sat Rx and Tutioune, so no chance of reflections in the shack.

All to go for...

The MK-802iv looks interesting, but can keep focused on the above as I don't have the device yet

See you on the forum.

73

Peter

[G4GUO]

I would hold off on the MK802IV we are now looking at the ODROID 3
which has a more modern Kernel.

Have you tried putting the command in ~/.bashrc

- Charles

[G8DKC]

Hi All,

From what I gather Charles has found a couple of bugs in Ver 2.02 of DATV-Express software,

and also possibly adding some extra setup options.

So we look forward to next release as and when.

73

Peter

[vk3pb]

Hi Charles de VK3PB

I see you have had a few problems with the Raspberry Pi and tv dongles.

May I suggest that you might wish to consider the Banana Pi as a possibly hardware solution to drive the DATV Express? It is relatively inexpensive (about $50 on Alibaba I believe)

http://www.lemaker.org/

http://www.alibaba.com/showroom/banana-pi.html

http://www.bananapi.org/

It can run the Raspberry Pi OS so you may not need to do a lot of new work. The good news is that it has a dual core processor.

cheers Peter

[vk3pb]

Some useful speed comparisons

http://hardware-libre.fr/2014/06/raspbe ... ware-duel/

cheers Peter

[G4GUO]

I should get my Odroid U3 later this week so it will be interesting to do some tests with that.

The issue I have found is that currently Express seems to only use one core on a multi-core
ARM device. Whether that is because process threads are not implemented in the distribution
I am using or not I don't know yet. It needs to be a kernel with SMP (Symmetric Multi Processing)
enabled.

Certainly on the PC the processing is spread between 4 cores, so Express does multi-thread.

I have been looking at OpenCL as well, but at the moment that is only supported on ARM devices
that use a T600 GPU (which is none of the cheap ones).

I think those benchmarks pretty much prove what I always thought about the PI.

- Charles

[G4GUO]

I now have my Odroid U3+ all setup and working. It took about a week after it arrived
for me to get it working as the power connector was a 2.5mm one and the HDMI was a type D,
neither of which were in my junk box. The Linux version of the board is shipping
with 14.04 LTS so it is running the latest release of Ubuntu albeit Lubuntu

Very little problems getting DATV-Express to run on it.

The GUI is much quicker than on the MK802IV mainly I suspect because hardkernel aka Odroid
have implement the GPU graphics acceleration which Picuntu is lacking.

I still have the issue when transmitting DVB-T , most of the processing is done by one
core. I will probably have to try the multi threaded version of FFTW to try and spread the
processing if that is not successful I will look at using the 4 MALI GPUS to do the iFFT.

Odroid produce a nice monthly free magazine http://magazine.odroid.com/
It also appears that they have GPU accelerated codec support (more investigation required)
and that they are actively developing accelerated GStreamer filters.

I bought mine direct from South Korea, they recommend EU customers buy them from
a company in Germany unfortunately that company's website was all in German. However
I notice there is another German distributor advertising in their magazine in English so
that might be worth a look.

So all in all it looks like a great way to go. Stay tuned!

- Charles G4GUO

[G0EID]

Hi Charles,
As the DATV-Express GUI needs quite a powerful cpu and graphics chip, maybe more in the future as you add new functionality?
How about command line options to DATV-Express?
For portable operation we could use multiple configuration files for changing Frequency, FEC, PID’s etc, when needed?
Multiple configurations could be built and saved using the GUI, then it would just be a case of running something like `DATV-Express –nogui –config=/path/to/datvexpress.cfg` to switch configurations.
Or maybe expose a few of the other common parameters that need to change like this:
# DATV-Express --nogui --fec=“1/2” --freq=437000000` then read the rest of the configuration from /users/home/.datvexpress/datvexpress.cfg as you do now.

Any reason why datvexpress.cfg is a binary file, could it be plaintext or XML so it could be edited without using the GUI?

If we had command line arguments and an editable configuration file then front panels, using LCD menus / push buttons or switches are possible, with the OS reading the values before starting the DATV-Express executable.
Appreciate your first priority is to provide a good all round experience using a GUI, but for portable use and repeaters, I think a set of command line options would be a good tools for building lightweight systems?

Dave

[G4GUO]

It takes time to do all these things and so far no one with the right software experience has offered to help.
I have had a few genuine offers of help but the problem is that those with the time don't have the experience
and those with the experience don't have the time.

The reason the .cfg file is in binary is that, that is the quickest way to do it. When the program settles down
that facility maybe added.

The ironic thing about this project is that there are no DATV repeater close enough for me to get into now
and there is no one local to me on DATV.

My only real hope is that Geostationary satellite.

- Charles

[G8DKC]

Hi All,

Based on Charles and Gem, ON7MA's findings, Odroid U3 on it's way to my QTH.

Time to jump in and see if we can repeat their results!

Datv-Express running on Ubuntu on, Odroid U3.

Looking forward to "stand alone" as it evolves.

Good luck and 73.

Peter

G8DKC