69 lines
3.0 KiB
HTML
69 lines
3.0 KiB
HTML
== Installation
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A typical installation involves attaching
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only a suitable battery, a single pole switch for
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power on/off, and two pairs of wires connecting e-matches for the
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apogee and main ejection charges. All Altus Metrum products are
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designed for use with single-cell batteries with 3.7 volts
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nominal.
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EasyMini may also be used with other
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batteries as long as they supply between 4 and 12 volts.
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The battery connectors are a standard 2-pin JST connector; you
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can purchase suitable batteries from the any vendor selling
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Altus Metrum products. These batteries are
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single-cell Lithium Polymer batteries that nominally provide 3.7
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volts. Other vendors sell similar batteries for RC aircraft
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using mating connectors, however the polarity for those is
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generally reversed from the batteries used by Altus Metrum
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products. In particular, the Tenergy batteries supplied for use
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in Featherweight flight computers are not compatible with Altus
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Metrum flight computers or battery chargers.
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[WARNING]
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Check polarity and voltage before connecting any battery not
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purchased from Altus Metrum.
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[WARNING]
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Spark Fun sells batteries that have a matching connector with
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the correct polarity. However, these batteries include an
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integrated current limiting circuit. That circuit will cause
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the battery to shut down when firing the igniter circuit. Do
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not use these batteries unless you remove the current limiting
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circuit.
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By default, we use the unregulated output of the battery
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directly to fire ejection charges. This works marvelously
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with standard low-current e-matches like the J-Tek from MJG
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Technologies, and with Quest Q2G2 igniters. However, if you
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want or need to use a separate pyro battery, check out
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<<_using_a_separate_pyro_battery>> for instructions on how to wire
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that up. The altimeters are designed to work with an external
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pyro battery of no more than 15 volts.
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Ejection charges are wired directly to the screw terminal block
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at the aft end of the altimeter. You'll need a very small straight
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blade screwdriver for these screws, such as you might find in a
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jeweler's screwdriver set.
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ifndef::telemini[]
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The screw terminal block is also used for the power switch leads.
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endif::telemini[]
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ifdef::telemini[]
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Except for TeleMini v1.0, the flight computers also use the
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screw terminal block for the power switch leads. On TeleMini v1.0,
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the power switch leads are soldered directly to the board and
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can be connected directly to a switch.
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endif::telemini[]
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ifdef::radio[]
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For most air-frames, the integrated antennas are more than
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adequate. However, if you are installing in a carbon-fiber or
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metal electronics bay which is opaque to RF signals, you may need to
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use off-board external antennas instead. In this case, you can
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replace the stock UHF antenna wire with an edge-launched SMA connector,
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and, on TeleMetrum v1, you can unplug the integrated GPS
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antenna and select an appropriate off-board GPS antenna with
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cable terminating in a U.FL connector.
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endif::radio[]
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