jks

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jks
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  • QZSS Support [GPS, added in v1.170]

    Well, the alert flag is on, but QZS-3/PRN199 seems to be up and decoding subframes! And the az/el is right where it's supposed to be. Also seen in Shenzhen and Adelaide, Australia.


    image
    KA7Ufractional_n
  • DANGER: DO NOT do a manual Debian/Linux upgrade to your Kiwi! (update: but it's okay now)

    We're not talking about the Kiwi auto-update process. That feature is perfectly fine and will continue as usual.

    We're talking about people who manually update/upgrade the underlying Debian/Linux system on the Kiwi by logging into the Beagle as root and running, for example, the "apt" command. Please don't do this. We only validate specific Debian distributions. If you update manually you run the risk of "bricking" your Kiwi server. That is, downloading something causing an unexpected side-effect which prevents the Kiwi server from running. This will stop further auto-updates and will require a manual intervention to fix. Possibly by re-flashing your Beagle using the Seeed SD-card and losing your entire Kiwi configuration (unless you've backed up).

    This is exactly what has happened since a change was made in late February by one of the Beagle developers that made its way into the Debian update stream. We've identified the problem and have asked them to make a change. But it is not clear when this might happen. If you have a Kiwi in this condition then please use the following workaround:

    Symptom: The Kiwi server won't stay running. The log shows it just crashes and restarts over and over again with the error "SYS_PANIC: open spidev".
    Workaround:

    1) ssh/PuTTY into your Kiwi Beagle as user "root" (no password).
    2) "cdp" Change to Kiwi build directory.
    3) "up" Manually pulls the latest version from Github (v1.175 or later) and builds it.
    4) When that's done do "cd unix_env/bb.org-overlays"
    5) Type "./install.sh" (note the "dot" before the slash)
    6) When that's done type "reboot"

    Now the Kiwi server should run after the reboot.

    If you upgrade from here things will break again until the Beagle developers can implement a permanent solution.

    KA7U
  • Can't Find my KiwiSDR [after change to static ip address]

    v1.174 now displays the ip address, assigned by DHCP or set statically, in the LEDs: http://kiwisdr.com/quickstart/index.html#id-leds

    krjones
  • GPS: Galileo reception possible on Kiwi? [working as of v1.178]

    The recent addition of the QZSS sats (Asia/Oceania reception only) increases the percentage of time enough sats are available for fixes (minimum 4 sats required). This is especially true for GPS antennas that don't have a full view of the sky (i.e. shadowed by terrain or buildings). It certainly made a big difference at my NZ location. Since the Galileo E1 signal transmits on a frequency compatible with the Kiwi the question has been asked if it can also be received. It has worldwide reception and so would be very helpful.

    I think the majority of Kiwi owners struggle just to get the supplied antenna near a window, let alone outside and up high. Anything we can do to increase the percentage of Kiwis with functioning GPS would be very useful (e.g. more candidate Kiwis to participate in direction finding experiments). Plus they benefit from automatic, accurate frequency calibration of the SDR.

    I don't know much about HF-DF / triangulation, but fortunately we have a Kiwi user that does. He's already got it working! See: http://hcab14.blogspot.com

    KA7U
  • DDC on FPGA

    Hi. That is an excellent question.

    If you look carefully at the free version of the DUC/DDC compiler provided with Vivado you'll see that it is not general purpose. It is targeted to the cell phone industry (LTE/CDMA) and does not have the bit widths, clock rates and decimation factors needed by the Kiwi.

    The Kiwi does take advantage of some Vivado IP blocks, like the DDS compiler. And it makes very heavy use of the Artix DSP blocks to save FPGA fabric gates. We also wanted to have a design fully independent of any FPGA manufacturer's architecture in case we need to change devices in the future. It was also a learning experience for us to implement everything from first principles.

    KA7Utrain04
  • DDC on FPGA

    Hi. That is an excellent question.

    If you look carefully at the free version of the DUC/DDC compiler provided with Vivado you'll see that it is not general purpose. It is targeted to the cell phone industry (LTE/CDMA) and does not have the bit widths, clock rates and decimation factors needed by the Kiwi.

    The Kiwi does take advantage of some Vivado IP blocks, like the DDS compiler. And it makes very heavy use of the Artix DSP blocks to save FPGA fabric gates. We also wanted to have a design fully independent of any FPGA manufacturer's architecture in case we need to change devices in the future. It was also a learning experience for us to implement everything from first principles.

    KA7Utrain04
  • QZSS Support [GPS, added in v1.170]

    v1.172 adds a switch to the admin page GPS tab called "include alerted?" that overrides the exclusion of alerted sats from the position fix. The alert "A" symbol will appear green instead of red when the sat is actually being used. It will be interesting to see if some position fixes get worse when alerted sats are included.

    fractional_n
  • QZSS Support [GPS, added in v1.170]

    I have recently moved to a new location where I have a limited view of the sky. Either blocked by other apartment buildings or a nearby (hopefully inactive) volcanic cone. The addition of the QZ sats really improves the amount of time I have enough sats in view (4) to compute location fixes.

    WA2ZKDfractional_n
  • QZSS Support [GPS, added in v1.170]

    I have recently moved to a new location where I have a limited view of the sky. Either blocked by other apartment buildings or a nearby (hopefully inactive) volcanic cone. The addition of the QZ sats really improves the amount of time I have enough sats in view (4) to compute location fixes.

    WA2ZKDfractional_n
  • QZSS Support [GPS, added in v1.170]

    Looks like PRN199 is being acquired now.

    fractional_n