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    <p>This is awesome!  to fixate on one detail, that is not related to
      the IHU..........I'm very interested in the AX5043 (particularly
      the native HDLC features, which sound suspiciously close to AX.25
      with a little help from the Pi/MCU).  Will the Raspberry Pi dev
      board / reference code also be on github at the link provided? 
      any ETA for that? Does that already exist somewhere on github?</p>
    <p><br>
    </p>
    <p>Thanks!</p>
    <p>-Zach, KJ4QLP<br>
    </p>
    <pre class="moz-signature" cols="72">Research Associate
Aerospace Systems Lab
Ted & Karyn Hume Center for National Security & Technology
Virginia Polytechnic Institute & State University
Work Phone: 540-231-4174
Cell Phone: 540-808-6305</pre>
    <div class="moz-cite-prefix">On 6/5/2018 11:54 AM, Michelle Thompson
      via Ground-Station wrote:<br>
    </div>
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cite="mid:CACvjz2VGTtGmuV1qusZhbfk9QNaVyLDVL2YJo=sud4or-cfw7A@mail.gmail.com">
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                          <div>A conference call was held on 31 May
                            2018. Presenting was Jonathan Brandenburg,
                            concerning his IHU project that he wishes to
                            publish. </div>
                          <div><br>
                          </div>
                          <div>Open Research Institute will support
                            publishing this open source Integrated
                            Housekeeping Unit (IHU) design intended for
                            amateur radio satellite service payloads. An
                            IHU is a flight computer, controlling all
                            the elements of the payload.</div>
                          <div><br>
                          </div>
                          <div>The call was held courtesy of National
                            Instruments conference bridge. Thank you to
                            Neel Pandeya for making it possible and for
                            supporting open source hardware and software
                            designs. </div>
                          <div><br>
                          </div>
                          <div>The design team for this IHU consists of
                            Zach Metzinger, Jordan Trewitt, Bill Reed,
                            and Jonathan Brandenburg. This started in
                            earnest about a year ago. It it not
                            radiation hardened by design, but is
                            entirely appropriate for low earth orbit
                            (LEO) use. </div>
                          <div><br>
                          </div>
                          <div>Initial design work was presented at the
                            2017 AMSAT Symposium. </div>
                          <div>This is a failover IHU design. It was two
                            fault-tolerant processors. The processor is
                            TI Hercules and the part number is
                            TMS570LS0914PGE. Each processor has two
                            cores, and each core operates in lock-step.
                            There is some flight heritage with this part
                            from the ICI Radar Satellite and a NASA
                            Robotic ARM. </div>
                          <div><br>
                          </div>
                          <div>Included in the design are twin
                            transceivers. The transceiver selected is
                            the AX5043.</div>
                          <div><br>
                          </div>
                          <div>A power amplifier design is in progress. </div>
                          <div>There is error correction on the
                            memories. </div>
                          <div>This IHU has two “sides”, with one
                            Hercules and one transceiver on each side.
                            There is diversity in the voltage
                            regulators, with the primary side powered by
                            a MAX1556A regulators and a secondary side
                            powered with LTI963As. The diversity in
                            voltage regulators is intended to provide
                            additional resilience. For each side, there
                            is a 3.3volt rail and a 1.2volt rail.</div>
                          <div><br>
                          </div>
                          <div>Software development has only just begun.
                            Layout is approximately 80% complete. </div>
                          <div><br>
                          </div>
                          <div>The board has 4 layers and relatively
                            good power consumption based on prototype
                            measurement. </div>
                          <div><br>
                          </div>
                          <div>UPSat from Libre Space was also
                            introduced and referenced.</div>
                          <div><br>
                          </div>
                          <div>OreSat is interested in collaborating and
                            learning more about this design.</div>
                          <div><br>
                          </div>
                          <div>Our consensus is CANbus or Ethernet for
                            flight hardware.</div>
                          <div><br>
                          </div>
                          <div>Jonathan has also made a Raspberry Pi
                            daughterboard for the AX5043. This allows
                            development with the transceiver independent
                            of the Hercules or IHU. </div>
                          <div><br>
                          </div>
                          <div>The drawbacks to the Hercules include
                            terrible documentation and a cumbersome
                            parameterized code generation process for
                            development. Jonathan believes he is getting
                            a handle on this and there is the
                            possibility of him producing improved
                            documentation for this design. </div>
                          <div><br>
                          </div>
                          <div>We also discussed the VA10820 - Radiation
                            Hardened ARM® Cortex®-M0 MCU <a
                              href="https://www.voragotech.com/products/va10820"
                              moz-do-not-send="true">https://www.voragotech.com/products/va10820</a>.
                            This is approximately $700, but has good
                            stats and a well-documented toolchain. There
                            is at least one design that is open source
                            that could be used as a basis for an IHU. </div>
                          <div><br>
                          </div>
                          <div>Jonathan to publish the IHU at <a
                              href="https://github.com/phase4space/payload-IHU"
                              moz-do-not-send="true">https://github.com/phase4space/payload-IHU</a></div>
                          <div>Jonathan and Michelle to press for review
                            of the design.</div>
                          <div><br>
                          </div>
                          <div>Michelle to publish minutes.</div>
                          <div><br>
                          </div>
                          <div>Michelle to arrange for additional IHU
                            conference calls. </div>
                          <div><br>
                          </div>
                          <div>Microsemi’s SmartFusion2 and PolarFire
                            devices were brought up outside of the
                            meeting.  They are actively advertising
                            radiation hardening for these parts and they
                            may be available now and should be
                            discussed. </div>
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