3 A typical installation involves attaching
4 only a suitable battery, a single pole switch for
5 power on/off, and two pairs of wires connecting e-matches for the
6 apogee and main ejection charges. All Altus Metrum products are
7 designed for use with single-cell batteries with 3.7 volts
8 nominal. TeleMini v2.0 and EasyMini may also be used with other
9 batteries as long as they supply between 4 and 12 volts.
11 The battery connectors are a standard 2-pin JST connector and
12 match batteries sold by Spark Fun. These batteries are
13 single-cell Lithium Polymer batteries that nominally provide 3.7
14 volts. Other vendors sell similar batteries for RC aircraft
15 using mating connectors, however the polarity for those is
16 generally reversed from the batteries used by Altus Metrum
17 products. In particular, the Tenergy batteries supplied for use
18 in Featherweight flight computers are not compatible with Altus
19 Metrum flight computers or battery chargers.
22 Check polarity and voltage before connecting any battery not
23 purchased from Altus Metrum or Spark Fun.
25 By default, we use the unregulated output of the battery directly
26 to fire ejection charges. This works marvelously with standard
27 low-current e-matches like the J-Tek from MJG Technologies, and with
28 Quest Q2G2 igniters. However, if you want or need to use a separate
29 pyro battery, check out the “External Pyro Battery” section in this
30 manual for instructions on how to wire that up. The altimeters are
31 designed to work with an external pyro battery of no more than 15 volts.
33 Ejection charges are wired directly to the screw terminal block
34 at the aft end of the altimeter. You'll need a very small straight
35 blade screwdriver for these screws, such as you might find in a
36 jeweler's screwdriver set.
38 Except for TeleMini v1.0, the flight computers also use the
39 screw terminal block for the power switch leads. On TeleMini v1.0,
40 the power switch leads are soldered directly to the board and
41 can be connected directly to a switch.
43 For most air-frames, the integrated antennas are more than
44 adequate. However, if you are installing in a carbon-fiber or
45 metal electronics bay which is opaque to RF signals, you may need to
46 use off-board external antennas instead. In this case, you can
47 replace the stock UHF antenna wire with an edge-launched SMA connector,
48 and, on TeleMetrum v1, you can unplug the integrated GPS
49 antenna and select an appropriate off-board GPS antenna with
50 cable terminating in a U.FL connector.