Friday 1 May 2015

Back to the Zynq project

 
Zynq + MyriadRF in 19 inch draw




Now that work is starting to wind down on DATV-Express I have started to look at
what to do next on the DATV front. 

Lime Microcircuits have recently reduced the price of their LMS6002D FPRF chip,
also the price of Zynq based CPU/FPGA boards is starting to come down, for
example the Z Turn   so I thought it was time to look again at the Zedboard I bought
used a while ago.

The picture shows a Zedboard connected via a low density FMC socket to a MyriadRF
board plugged into a Zipper adapter. The PSU to the left is a DC-DC supply for a
car computer and supplies 12v 5v and 3v3 at reasonable current levels to power the
system.

The last few days I have been attempting to create a PetaLinux BSP for the hardware,
after a lot of work I finally have managed to create a basic Linux install for the system
with I2C and SPI support. I hit all the problems that everyone else seem to hit, mainly
with the configuration of the device tree. While this has been very frustrating it has
forced me to learn quite a lot about low level Linux support on ARM platforms.

The next job will be to write the code to configure the MyriadRF then I have to decide
on how I intend to do the signal processing.

For those not familiar with the Zynq, it is basically an FPGA with two ARM cores
connected in the fabric, it also has all the usual ARM peripherals like I2C, SPI,
Ethernet etc.

What I would like to do is to implement the DATV-Express software on it to begin
with, then to add the DPD (Digital Pre Distortion), then DVB-S/T receive. There
may be other things like video capture and MPEG encoding that could be added
but that would be a lot of work and I may not bother as even low end ARM boards
can do that sort of thing now.

My current thoughts are to use one CPU for Linux and the other (in combination
with the programmable logic) to do the DVB-S/T encoding / decoding and DPD.

Even with all these goodies the system still looks expensive, the solution maybe
to throw in a SDR transceiver as well. For the moment this will just be a personal
project. I will let you know how things progress.

2 comments:

  1. Hi Charles,

    It looks like you have plenty of projects already going, I'm wondering if you have had the chance to evaluate these:

    http://www.ebay.com/itm/221751001434?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

    http://www.ebay.com/itm/321737727449?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

    I just picked up a pair, the price is right and they seem to do work well, I have not yet had a chance to do an in depth evaluation.

    Mike KM7MH

    ReplyDelete
  2. Hello Mike,
    I have not used those particular Hides units, I do have the narrowband USB
    receive dongle from them but Ham DVB-T is more popular in the US than it
    is here so other than sending video to myself I can't make any informed
    comment.

    - Charles

    ReplyDelete