1 == Using Altus Metrum Products
8 link:http://www.altusmetrum.org/Radio/[amateur radio license]
9 or other authorization to legally operate the radio
10 transmitters that are part of our products.
17 In the rocket itself, you just need a flight computer
18 and a single-cell, 3.7 volt nominal Li-Po rechargeable
20 ifdef::telemetrum,telemega,easymega,easytimer[]
21 An 850mAh battery weighs less than a 9V
22 alkaline battery, and will run a TeleMetrum, TeleMega,
23 EasyMega or EasyTimer for hours.
24 endif::telemetrum,telemega,easymega,easytimer[]
25 A 110mAh battery weighs less
26 than a triple A battery and is a good choice for use
28 ifdef::telemini[TeleMini or]
32 By default, we ship TeleMini, TeleMetrum and TeleMega
33 flight computers with a simple wire antenna. If your
34 electronics bay or the air-frame it resides within is
35 made of carbon fiber, which is opaque to RF signals,
36 you may prefer to install an SMA connector so that you
37 can run a coaxial cable to an antenna mounted
38 elsewhere in the rocket. However, note that the GPS
39 antenna is fixed on all current products, so you
40 really want to install the flight computer in a bay
41 made of RF-transparent materials if at all possible.
47 To receive the data stream from the rocket, you need
48 an antenna and short feed-line connected to one of our
49 link:http://www.altusmetrum.org/TeleDongle/[TeleDongle]
50 units. If possible, use an SMA to BNC adapter instead
51 of feedline between the antenna feedpoint and
52 TeleDongle, as this will give you the best
53 performance. The TeleDongle in turn plugs directly
54 into the USB port on a notebook computer. Because
55 TeleDongle looks like a simple serial port, your
56 computer does not require special device
57 drivers... just plug it in.
60 The GUI tool, AltosUI, is written in Java and runs
61 across Linux, Mac OS and Windows. There's also a suite
62 of C tools for Linux which can perform most of the
66 Alternatively, a TeleBT attached with an SMA to BNC
67 adapter at the feed point of a hand-held yagi used in
68 conjunction with an Android device running AltosDroid
69 makes an outstanding ground station.
74 you can use the radio link to
75 extract the more detailed data logged in either
76 TeleMetrum or TeleMini devices, or
79 USB cable to plug into the flight computer board directly.
80 A USB cable is also how you
81 charge the Li-Po battery, so you'll want one of those
82 anyway. The same cable used by lots of digital
83 cameras and other modern electronic stuff will work
87 If your rocket lands out of sight, you may enjoy
88 having a hand-held GPS receiver, so that you can put
89 in a way-point for the last reported rocket position
90 before touch-down. This makes looking for your rocket
91 a lot like Geo-Caching... just go to the way-point and
92 look around starting from there. AltosDroid on an
93 Android device with GPS receiver works great for this,
98 You may also enjoy having a ham radio “HT” that covers
99 the 70cm band... you can use that with your antenna to
100 direction-find the rocket on the ground the same way
101 you can use a Walston or Beeline tracker. This can be
102 handy if the rocket is hiding in sage brush or a tree,
103 or if the last GPS position doesn't get you close
104 enough because the rocket dropped into a canyon, or
105 the wind is blowing it across a dry lake bed, or
106 something like that... Keith currently uses a Yaesu
107 FT1D, Bdale has a Yaesu VX-7R, which is a nicer radio
108 in most ways but doesn't support APRS.
110 So, to recap, on the ground the hardware you'll need includes:
112 . an antenna and feed-line or adapter
114 . a notebook computer
115 . optionally, a hand-held GPS receiver
116 . optionally, an HT or receiver covering 435 MHz
118 The best hand-held commercial directional antennas we've found for radio
119 direction finding rockets are from
120 link:http://www.arrowantennas.com/[Arrow Antennas].
122 The 440-3 and 440-5 are both good choices for finding
123 a TeleMetrum- or TeleMini- equipped rocket when used
124 with a suitable 70cm HT. TeleDongle and an SMA to BNC
125 adapter fit perfectly between the driven element and
126 reflector of Arrow antennas.
131 Our software makes it easy to log the data from each
132 flight, both the telemetry received during the flight
133 itself, and the more complete data log recorded in the
134 flash memory on the altimeter board. Once this data
135 is on your computer, our post-flight tools make it
136 easy to quickly get to the numbers everyone wants,
137 like apogee altitude, max acceleration, and max
138 velocity. You can also generate and view a standard
139 set of plots showing the altitude, acceleration, and
140 velocity of the rocket during flight. And you can
141 even export a flight log in a format usable with Google
142 Maps and Google Earth for visualizing the flight path
143 in two or three dimensions!
145 Our ultimate goal is to emit a set of files for each
146 flight that can be published as a web page per flight,
147 or just viewed on your local disk with a web browser.
151 ifdef::telemetrum,telemega,easymega[]
152 We have designed and prototyped several “companion
153 boards” that can attach to the companion connector on
154 TeleMetrum, TeleMega and EasyMega flight computers to
155 collect more data, provide more pyro channels, and so
156 forth. We do not yet know if or when any of these
157 boards will be produced in enough quantity to sell.
158 If you have specific interests for data collection or
159 control of events in your rockets beyond the
160 capabilities of our existing productions, please let
162 endif::telemetrum,telemega,easymega[]
164 Because all of our work is open, both the hardware
165 designs and the software, if you have some great idea
166 for an addition to the current Altus Metrum family,
167 feel free to dive in and help! Or let us know what
168 you'd like to see that we aren't already working on,
169 and maybe we'll get excited about it too...
171 Watch our link:http://altusmetrum.org/[web site] for
172 more news and information as our family of products