power on/off, and two pairs of wires connecting e-matches for the
apogee and main ejection charges. All Altus Metrum products are
designed for use with single-cell batteries with 3.7 volts
- nominal. TeleMini v2.0 and EasyMini may also be used with other
+ nominal.
+ ifdef::telemini[TeleMini v2.0 and]
+ EasyMini may also be used with other
batteries as long as they supply between 4 and 12 volts.
- The battery connectors are a standard 2-pin JST connector and
- match batteries sold by Spark Fun. These batteries are
+ The battery connectors are a standard 2-pin JST connector; you
+ can purchase suitable batteries from the any vendor selling
+ Altus Metrum products. These batteries are
single-cell Lithium Polymer batteries that nominally provide 3.7
volts. Other vendors sell similar batteries for RC aircraft
using mating connectors, however the polarity for those is
[WARNING]
Check polarity and voltage before connecting any battery not
- purchased from Altus Metrum or Spark Fun.
+ purchased from Altus Metrum.
+
+ [WARNING]
+ Spark Fun sells batteries that have a matching connector with
+ the correct polarity. However, these batteries include an
+ integrated current limiting circuit. That circuit will cause
+ the battery to shut down when firing the igniter circuit. Do
+ not use these batteries unless you remove the current limiting
+ circuit.
By default, we use the unregulated output of the battery
directly to fire ejection charges. This works marvelously
at the aft end of the altimeter. You'll need a very small straight
blade screwdriver for these screws, such as you might find in a
jeweler's screwdriver set.
+ ifndef::telemini[]
+ The screw terminal block is also used for the power switch leads.
+ endif::telemini[]
+ ifdef::telemini[]
Except for TeleMini v1.0, the flight computers also use the
screw terminal block for the power switch leads. On TeleMini v1.0,
the power switch leads are soldered directly to the board and
can be connected directly to a switch.
+ endif::telemini[]
+ ifdef::radio[]
For most air-frames, the integrated antennas are more than
adequate. However, if you are installing in a carbon-fiber or
metal electronics bay which is opaque to RF signals, you may need to
and, on TeleMetrum v1, you can unplug the integrated GPS
antenna and select an appropriate off-board GPS antenna with
cable terminating in a U.FL connector.
+ endif::radio[]