+ </p></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="idp38859952"></a>Chapter 4. Altus Metrum Hardware</h1></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="section"><a href="#idp38860624">1. General Usage Instructions</a></span></dt><dd><dl><dt><span class="section"><a href="#idp38862592">1.1. Hooking Up Lithium Polymer Batteries</a></span></dt><dt><span class="section"><a href="#idp42276480">1.2. Hooking Up Pyro Charges</a></span></dt><dt><span class="section"><a href="#idp42591936">1.3. Hooking Up a Power Switch</a></span></dt><dt><span class="section"><a href="#idp40956544">1.4. Using a Separate Pyro Battery</a></span></dt><dt><span class="section"><a href="#idp40258464">1.5. Using a Different Kind of Battery</a></span></dt></dl></dd><dt><span class="section"><a href="#idp43170688">2. Specifications</a></span></dt><dt><span class="section"><a href="#idp44431104">3. TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#idp44436000">3.1. TeleMetrum Screw Terminals</a></span></dt><dt><span class="section"><a href="#idp44455216">3.2. Using a Separate Pyro Battery with TeleMetrum</a></span></dt><dt><span class="section"><a href="#idp44458464">3.3. Using an Active Switch with TeleMetrum</a></span></dt></dl></dd><dt><span class="section"><a href="#idp44460592">4. TeleMini v1.0</a></span></dt><dd><dl><dt><span class="section"><a href="#idp44465488">4.1. TeleMini v1.0 Screw Terminals</a></span></dt><dt><span class="section"><a href="#idp44484832">4.2. Using a Separate Pyro Battery with TeleMini v1.0</a></span></dt><dt><span class="section"><a href="#idp44488208">4.3. Using an Active Switch with TeleMini v1.0</a></span></dt></dl></dd><dt><span class="section"><a href="#idp44490416">5. TeleMini v2.0</a></span></dt><dd><dl><dt><span class="section"><a href="#idp44494432">5.1. TeleMini v2.0 Screw Terminals</a></span></dt><dt><span class="section"><a href="#idp44516816">5.2. Using a Separate Pyro Battery with TeleMini v2.0</a></span></dt><dt><span class="section"><a href="#idp44520016">5.3. Using an Active Switch with TeleMini v2.0</a></span></dt></dl></dd><dt><span class="section"><a href="#idp44522112">6. EasyMini</a></span></dt><dd><dl><dt><span class="section"><a href="#idp44525968">6.1. EasyMini Screw Terminals</a></span></dt><dt><span class="section"><a href="#idp44548352">6.2. Using a Separate Pyro Battery with EasyMini</a></span></dt><dt><span class="section"><a href="#idp44551536">6.3. Using an Active Switch with EasyMini</a></span></dt></dl></dd><dt><span class="section"><a href="#idp44553632">7. TeleMega</a></span></dt><dd><dl><dt><span class="section"><a href="#idp44557600">7.1. TeleMega Screw Terminals</a></span></dt><dt><span class="section"><a href="#idp44595104">7.2. Using a Separate Pyro Battery with TeleMega</a></span></dt><dt><span class="section"><a href="#idp44596704">7.3. Using Only One Battery With TeleMega</a></span></dt><dt><span class="section"><a href="#idp44598624">7.4. Using an Active Switch with TeleMega</a></span></dt></dl></dd><dt><span class="section"><a href="#idp44600672">8. Flight Data Recording</a></span></dt><dt><span class="section"><a href="#idp44629504">9. Installation</a></span></dt></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp38860624"></a>1. General Usage Instructions</h2></div></div></div><p>
+ Here are general instructions for hooking up an Altus Metrum
+ flight computer. Instructions specific to each model will be
+ found in the section devoted to that model below.
+ </p><p>
+ To prevent electrical interference from affecting the
+ operation of the flight computer, it's important to always
+ twist pairs of wires connected to the board. Twist the switch
+ leads, the pyro leads and the battery leads. This reduces
+ interference through a mechanism called common mode rejection.
+ </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp38862592"></a>1.1. Hooking Up Lithium Polymer Batteries</h3></div></div></div><p>
+ All Altus Metrum flight computers have a two pin JST PH
+ series connector to connect up a single-cell Lithium Polymer
+ cell (3.7V nominal). You can purchase matching batteries
+ from the Altus Metrum store, or other vendors, or you can
+ make your own. Pin 1 of the connector is positive, pin 2 is
+ negative. Spark Fun sells a cable with the connector
+ attached, which they call a <a class="ulink" href="https://www.sparkfun.com/products/9914" target="_top">JST Jumper 2
+ Wire Assembly</a>.
+ </p><p>
+ Many RC vendors also sell lithium polymer batteries with
+ this same connector. All that we have found use the opposite
+ polarity, and if you use them that way, you will damage or
+ destroy the flight computer.
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp42276480"></a>1.2. Hooking Up Pyro Charges</h3></div></div></div><p>
+ Altus Metrum flight computers always have two screws for
+ each pyro charge. This means you shouldn't need to put two
+ wires into a screw terminal or connect leads from pyro
+ charges together externally.
+ </p><p>
+ On the flight computer, one lead from each charge is hooked
+ to the positive battery terminal through the power switch.
+ The other lead is connected through the pyro circuit, which
+ is connected to the negative battery terminal when the pyro
+ circuit is fired.
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp42591936"></a>1.3. Hooking Up a Power Switch</h3></div></div></div><p>
+ Altus Metrum flight computers need an external power switch
+ to turn them on. This disconnects both the computer and the
+ pyro charges from the battery, preventing the charges from
+ firing when in the Off position. The switch is in-line with
+ the positive battery terminal.
+ </p><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="idp42971904"></a>1.3.1. Using an External Active Switch Circuit</h4></div></div></div><p>
+ You can use an active switch circuit, such as the
+ Featherweight Magnetic Switch, with any Altus Metrum
+ flight computer. These require three connections, one to
+ the battery, one to the positive power input on the flight
+ computer and one to ground. Find instructions on how to
+ hook these up for each flight computer below. The follow
+ the instructions that come with your active switch to
+ connect it up.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp40956544"></a>1.4. Using a Separate Pyro Battery</h3></div></div></div><p>
+ As mentioned above in the section on hooking up pyro
+ charges, one lead for each of the pyro charges is connected
+ through the power switch directly to the positive battery
+ terminal. The other lead is connected to the pyro circuit,
+ which connects it to the negative battery terminal when the
+ pyro circuit is fired. The pyro circuit on all of the flight
+ computers is designed to handle up to 16V.
+ </p><p>
+ To use a separate pyro battery, connect the negative pyro
+ battery terminal to the flight computer ground terminal,
+ the positive battery terminal to the igniter and the other
+ igniter lead to the negative pyro terminal on the flight
+ computer. When the pyro channel fires, it will complete the
+ circuit between the negative pyro terminal and the ground
+ terminal, firing the igniter. Specific instructions on how
+ to hook this up will be found in each section below.
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp40258464"></a>1.5. Using a Different Kind of Battery</h3></div></div></div><p>
+ EasyMini and TeleMini v2 are designed to use either a
+ lithium polymer battery or any other battery producing
+ between 4 and 12 volts, such as a rectangular 9V
+ battery. TeleMega and TeleMetrum are not designed for this,
+ and must only be powered by a lithium polymer battery. Find
+ instructions on how to use other batteries in the EasyMini
+ and TeleMini sections below.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp43170688"></a>2. Specifications</h2></div></div></div><p>
+ Here's the full set of Altus Metrum products, both in
+ production and retired.
+ </p><div class="table"><a name="idp42978752"></a><p class="title"><b>Table 4.1. Altus Metrum Electronics</b></p><div class="table-contents"><table summary="Altus Metrum Electronics" border="1"><colgroup><col align="center" class="Device"><col align="center" class="Barometer"><col align="center" class="Z-axis accelerometer"><col align="center" class="GPS"><col align="center" class="3D sensors"><col align="center" class="Storage"><col align="center" class="RF"><col align="center" class="Battery"></colgroup><thead><tr><th align="center">Device</th><th align="center">Barometer</th><th align="center">Z-axis accelerometer</th><th align="center">GPS</th><th align="center">3D sensors</th><th align="center">Storage</th><th align="center">RF Output</th><th align="center">Battery</th></tr></thead><tbody><tr><td align="center">TeleMetrum v1.0</td><td align="center"><p>MP3H6115 10km (33k')</p></td><td align="center"><p>MMA2202 50g</p></td><td align="center">SkyTraq</td><td align="center">-</td><td align="center">1MB</td><td align="center">10mW</td><td align="center">3.7V</td></tr><tr><td align="center">TeleMetrum v1.1</td><td align="center"><p>MP3H6115 10km (33k')</p></td><td align="center"><p>MMA2202 50g</p></td><td align="center">SkyTraq</td><td align="center">-</td><td align="center">2MB</td><td align="center">10mW</td><td align="center">3.7V</td></tr><tr><td align="center">TeleMetrum v1.2</td><td align="center"><p>MP3H6115 10km (33k')</p></td><td align="center"><p>ADXL78 70g</p></td><td align="center">SkyTraq</td><td align="center">-</td><td align="center">2MB</td><td align="center">10mW</td><td align="center">3.7V</td></tr><tr><td align="center">TeleMetrum v2.0</td><td align="center"><p>MS5607 30km (100k')</p></td><td align="center"><p>MMA6555 102g</p></td><td align="center">uBlox Max-7Q</td><td align="center">-</td><td align="center">8MB</td><td align="center">40mW</td><td align="center">3.7V</td></tr><tr><td align="center"><p>TeleMini v1.0</p></td><td align="center"><p>MP3H6115 10km (33k')</p></td><td align="center">-</td><td align="center">-</td><td align="center">-</td><td align="center">5kB</td><td align="center">10mW</td><td align="center">3.7V</td></tr><tr><td align="center">TeleMini v2.0</td><td align="center"><p>MS5607 30km (100k')</p></td><td align="center">-</td><td align="center">-</td><td align="center">-</td><td align="center">1MB</td><td align="center">10mW</td><td align="center">3.7-12V</td></tr><tr><td align="center">EasyMini v1.0</td><td align="center"><p>MS5607 30km (100k')</p></td><td align="center">-</td><td align="center">-</td><td align="center">-</td><td align="center">1MB</td><td align="center">-</td><td align="center">3.7-12V</td></tr><tr><td align="center">TeleMega v1.0</td><td align="center"><p>MS5607 30km (100k')</p></td><td align="center"><p>MMA6555 102g</p></td><td align="center">uBlox Max-7Q</td><td align="center"><p>MPU6000 HMC5883</p></td><td align="center">8MB</td><td align="center">40mW</td><td align="center">3.7V</td></tr></tbody></table></div></div><br class="table-break"><div class="table"><a name="idp44395088"></a><p class="title"><b>Table 4.2. Altus Metrum Boards</b></p><div class="table-contents"><table summary="Altus Metrum Boards" border="1"><colgroup><col align="center" class="Device"><col align="center" class="Connectors"><col align="center" class="Screw Terminals"><col align="center" class="Width"><col align="center" class="Length"><col align="center" class="Tube Size"></colgroup><thead><tr><th align="center">Device</th><th align="center">Connectors</th><th align="center">Screw Terminals</th><th align="center">Width</th><th align="center">Length</th><th align="center">Tube Size</th></tr></thead><tbody><tr><td align="center">TeleMetrum</td><td align="center"><p>
+ Antenna
+ Debug
+ Companion
+ USB
+ Battery
+ </p></td><td align="center"><p>Apogee pyro Main pyro Switch</p></td><td align="center">1 inch (2.54cm)</td><td align="center">2 ¾ inch (6.99cm)</td><td align="center">29mm coupler</td></tr><tr><td align="center"><p>TeleMini v1.0</p></td><td align="center"><p>
+ Antenna
+ Debug
+ Battery
+ </p></td><td align="center"><p>
+ Apogee pyro
+ Main pyro
+ </p></td><td align="center">½ inch (1.27cm)</td><td align="center">1½ inch (3.81cm)</td><td align="center">18mm coupler</td></tr><tr><td align="center">TeleMini v2.0</td><td align="center"><p>
+ Antenna
+ Debug
+ USB
+ Battery
+ </p></td><td align="center"><p>
+ Apogee pyro
+ Main pyro
+ Battery
+ Switch
+ </p></td><td align="center">0.8 inch (2.03cm)</td><td align="center">1½ inch (3.81cm)</td><td align="center">24mm coupler</td></tr><tr><td align="center">EasyMini</td><td align="center"><p>
+ Debug
+ USB
+ Battery
+ </p></td><td align="center"><p>
+ Apogee pyro
+ Main pyro
+ Battery
+ Switch
+ </p></td><td align="center">0.8 inch (2.03cm)</td><td align="center">1½ inch (3.81cm)</td><td align="center">24mm coupler</td></tr><tr><td align="center">TeleMega</td><td align="center"><p>
+ Antenna
+ Debug
+ Companion
+ USB
+ Battery
+ </p></td><td align="center"><p>
+ Apogee pyro
+ Main pyro
+ Pyro A-D
+ Switch
+ Pyro battery
+ </p></td><td align="center">1¼ inch (3.18cm)</td><td align="center">3¼ inch (8.26cm)</td><td align="center">38mm coupler</td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44431104"></a>3. TeleMetrum</h2></div></div></div><div class="informalfigure"><div class="mediaobject"><table border="0" summary="manufactured viewport for HTML img" style="cellpadding: 0; cellspacing: 0;" width="495"><tr><td><img src="telemetrum-v1.1-thside.jpg" width="495"></td></tr></table></div></div><p>
+ TeleMetrum is a 1 inch by 2¾ inch circuit board. It was designed to
+ fit inside coupler for 29mm air-frame tubing, but using it in a tube that
+ small in diameter may require some creativity in mounting and wiring
+ to succeed! The presence of an accelerometer means TeleMetrum should
+ be aligned along the flight axis of the airframe, and by default the ¼
+ wave UHF wire antenna should be on the nose-cone end of the board. The
+ antenna wire is about 7 inches long, and wiring for a power switch and
+ the e-matches for apogee and main ejection charges depart from the
+ fin can end of the board, meaning an ideal “simple” avionics
+ bay for TeleMetrum should have at least 10 inches of interior length.
+ </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44436000"></a>3.1. TeleMetrum Screw Terminals</h3></div></div></div><p>
+ TeleMetrum has six screw terminals on the end of the board
+ opposite the telemetry antenna. Two are for the power
+ switch, and two each for the apogee and main igniter
+ circuits. Using the picture above and starting from the top,
+ the terminals are as follows:
+ </p><div class="table"><a name="idp44437312"></a><p class="title"><b>Table 4.3. TeleMetrum Screw Terminals</b></p><div class="table-contents"><table summary="TeleMetrum Screw Terminals" border="1"><colgroup><col align="center" class="Pin #"><col align="center" class="Pin Name"><col align="left" class="Description"></colgroup><thead><tr><th align="center">Terminal #</th><th align="center">Terminal Name</th><th align="center">Description</th></tr></thead><tbody><tr><td align="center">1</td><td align="center">Switch Output</td><td align="left">Switch connection to flight computer</td></tr><tr><td align="center">2</td><td align="center">Switch Input</td><td align="left">Switch connection to positive battery terminal</td></tr><tr><td align="center">3</td><td align="center">Main +</td><td align="left">Main pyro channel common connection to battery +</td></tr><tr><td align="center">4</td><td align="center">Main -</td><td align="left">Main pyro channel connection to pyro circuit</td></tr><tr><td align="center">5</td><td align="center">Apogee +</td><td align="left">Apogee pyro channel common connection to battery +</td></tr><tr><td align="center">6</td><td align="center">Apogee -</td><td align="left">Apogee pyro channel connection to pyro circuit</td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44455216"></a>3.2. Using a Separate Pyro Battery with TeleMetrum</h3></div></div></div><p>
+ As described above, using an external pyro battery involves
+ connecting the negative battery terminal to the flight
+ computer ground, connecting the positive battery terminal to
+ one of the igniter leads and connecting the other igniter
+ lead to the per-channel pyro circuit connection.
+ </p><p>
+ To connect the negative battery terminal to the TeleMetrum
+ ground, insert a small piece of wire, 24 to 28 gauge
+ stranded, into the GND hole just above the screw terminal
+ strip and solder it in place.
+ </p><p>
+ Connecting the positive battery terminal to the pyro
+ charges must be done separate from TeleMetrum, by soldering
+ them together or using some other connector.
+ </p><p>
+ The other lead from each pyro charge is then inserted into
+ the appropriate per-pyro channel screw terminal (terminal 4 for the
+ Main charge, terminal 6 for the Apogee charge).
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44458464"></a>3.3. Using an Active Switch with TeleMetrum</h3></div></div></div><p>
+ As explained above, an external active switch requires three
+ connections, one to the positive battery terminal, one to
+ the flight computer positive input and one to ground.
+ </p><p>
+ The positive battery terminal is available on screw terminal
+ 2, the positive flight computer input is on terminal 1. To
+ hook a lead to ground, solder a piece of wire, 24 to 28
+ gauge stranded, to the GND hole just above terminal 1.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44460592"></a>4. TeleMini v1.0</h2></div></div></div><div class="informalfigure"><div class="mediaobject"><table border="0" summary="manufactured viewport for HTML img" style="cellpadding: 0; cellspacing: 0;" width="495"><tr><td><img src="telemini-v1-top.jpg" width="495"></td></tr></table></div></div><p>
+ TeleMini v1.0 is ½ inches by 1½ inches. It was
+ designed to fit inside an 18mm air-frame tube, but using it in
+ a tube that small in diameter may require some creativity in
+ mounting and wiring to succeed! Since there is no
+ accelerometer, TeleMini can be mounted in any convenient
+ orientation. The default ¼ wave UHF wire antenna attached to
+ the center of one end of the board is about 7 inches long. Two
+ wires for the power switch are connected to holes in the
+ middle of the board. Screw terminals for the e-matches for
+ apogee and main ejection charges depart from the other end of
+ the board, meaning an ideal “simple” avionics bay for TeleMini
+ should have at least 9 inches of interior length.
+ </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44465488"></a>4.1. TeleMini v1.0 Screw Terminals</h3></div></div></div><p>
+ TeleMini v1.0 has four screw terminals on the end of the
+ board opposite the telemetry antenna. Two are for the apogee
+ and two are for main igniter circuits. There are also wires
+ soldered to the board for the power switch. Using the
+ picture above and starting from the top for the terminals
+ and from the left for the power switch wires, the
+ connections are as follows:
+ </p><div class="table"><a name="idp44466928"></a><p class="title"><b>Table 4.4. TeleMini v1.0 Connections</b></p><div class="table-contents"><table summary="TeleMini v1.0 Connections" border="1"><colgroup><col align="center" class="Pin #"><col align="center" class="Pin Name"><col align="left" class="Description"></colgroup><thead><tr><th align="center">Terminal #</th><th align="center">Terminal Name</th><th align="center">Description</th></tr></thead><tbody><tr><td align="center">1</td><td align="center">Apogee -</td><td align="left">Apogee pyro channel connection to pyro circuit</td></tr><tr><td align="center">2</td><td align="center">Apogee +</td><td align="left">Apogee pyro channel common connection to battery +</td></tr><tr><td align="center">3</td><td align="center">Main -</td><td align="left">Main pyro channel connection to pyro circuit</td></tr><tr><td align="center">4</td><td align="center">Main +</td><td align="left">Main pyro channel common connection to battery +</td></tr><tr><td align="center">Left</td><td align="center">Switch Output</td><td align="left">Switch connection to flight computer</td></tr><tr><td align="center">Right</td><td align="center">Switch Input</td><td align="left">Switch connection to positive battery terminal</td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44484832"></a>4.2. Using a Separate Pyro Battery with TeleMini v1.0</h3></div></div></div><p>
+ As described above, using an external pyro battery involves
+ connecting the negative battery terminal to the flight
+ computer ground, connecting the positive battery terminal to
+ one of the igniter leads and connecting the other igniter
+ lead to the per-channel pyro circuit connection. Because
+ there is no solid ground connection to use on TeleMini, this
+ is not recommended.
+ </p><p>
+ The only available ground connection on TeleMini v1.0 are
+ the two mounting holes next to the telemetry
+ antenna. Somehow connect a small piece of wire to one of
+ those holes and hook it to the negative pyro battery terminal.
+ </p><p>
+ Connecting the positive battery terminal to the pyro
+ charges must be done separate from TeleMini v1.0, by soldering
+ them together or using some other connector.
+ </p><p>
+ The other lead from each pyro charge is then inserted into
+ the appropriate per-pyro channel screw terminal (terminal 3 for the
+ Main charge, terminal 1 for the Apogee charge).
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44488208"></a>4.3. Using an Active Switch with TeleMini v1.0</h3></div></div></div><p>
+ As explained above, an external active switch requires three
+ connections, one to the positive battery terminal, one to
+ the flight computer positive input and one to ground. Again,
+ because TeleMini doesn't have any good ground connection,
+ this is not recommended.
+ </p><p>
+ The positive battery terminal is available on the Right
+ power switch wire, the positive flight computer input is on
+ the left power switch wire. Hook a lead to either of the
+ mounting holes for a ground connection.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44490416"></a>5. TeleMini v2.0</h2></div></div></div><div class="informalfigure"><div class="mediaobject"><table border="0" summary="manufactured viewport for HTML img" style="cellpadding: 0; cellspacing: 0;" width="495"><tr><td><img src="telemini-v2-top.jpg" width="495"></td></tr></table></div></div><p>
+ TeleMini v2.0 is 0.8 inches by 1½ inches. It adds more
+ on-board data logging memory, a built-in USB connector and
+ screw terminals for the battery and power switch. The larger
+ board fits in a 24mm coupler. There's also a battery connector
+ for a LiPo battery if you want to use one of those.
+ </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44494432"></a>5.1. TeleMini v2.0 Screw Terminals</h3></div></div></div><p>
+ TeleMini v2.0 has two sets of four screw terminals on the end of the
+ board opposite the telemetry antenna. Using the picture
+ above, the top four have connections for the main pyro
+ circuit and an external battery and the bottom four have
+ connections for the apogee pyro circuit and the power
+ switch. Counting from the left, the connections are as follows:
+ </p><div class="table"><a name="idp44495840"></a><p class="title"><b>Table 4.5. TeleMini v2.0 Connections</b></p><div class="table-contents"><table summary="TeleMini v2.0 Connections" border="1"><colgroup><col align="center" class="Pin #"><col align="center" class="Pin Name"><col align="left" class="Description"></colgroup><thead><tr><th align="center">Terminal #</th><th align="center">Terminal Name</th><th align="center">Description</th></tr></thead><tbody><tr><td align="center">Top 1</td><td align="center">Main -</td><td align="left">Main pyro channel connection to pyro circuit</td></tr><tr><td align="center">Top 2</td><td align="center">Main +</td><td align="left">Main pyro channel common connection to battery +</td></tr><tr><td align="center">Top 3</td><td align="center">Battery +</td><td align="left">Positive external battery terminal</td></tr><tr><td align="center">Top 4</td><td align="center">Battery -</td><td align="left">Negative external battery terminal</td></tr><tr><td align="center">Bottom 1</td><td align="center">Apogee -</td><td align="left">Apogee pyro channel connection to pyro circuit</td></tr><tr><td align="center">Bottom 2</td><td align="center">Apogee +</td><td align="left">Apogee pyro channel common connection to
+ battery +</td></tr><tr><td align="center">Bottom 3</td><td align="center">Switch Output</td><td align="left">Switch connection to flight computer</td></tr><tr><td align="center">Bottom 4</td><td align="center">Switch Input</td><td align="left">Switch connection to positive battery terminal</td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44516816"></a>5.2. Using a Separate Pyro Battery with TeleMini v2.0</h3></div></div></div><p>
+ As described above, using an external pyro battery involves
+ connecting the negative battery terminal to the flight
+ computer ground, connecting the positive battery terminal to
+ one of the igniter leads and connecting the other igniter
+ lead to the per-channel pyro circuit connection.
+ </p><p>
+ To connect the negative pyro battery terminal to TeleMini
+ ground, connect it to the negative external battery
+ connection, top terminal 4.
+ </p><p>
+ Connecting the positive battery terminal to the pyro
+ charges must be done separate from TeleMini v2.0, by soldering
+ them together or using some other connector.
+ </p><p>
+ The other lead from each pyro charge is then inserted into
+ the appropriate per-pyro channel screw terminal (top
+ terminal 1 for the Main charge, bottom terminal 1 for the
+ Apogee charge).
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44520016"></a>5.3. Using an Active Switch with TeleMini v2.0</h3></div></div></div><p>
+ As explained above, an external active switch requires three
+ connections, one to the positive battery terminal, one to
+ the flight computer positive input and one to ground. Use
+ the negative external battery connection, top terminal 4 for
+ ground.
+ </p><p>
+ The positive battery terminal is available on bottom
+ terminal 4, the positive flight computer input is on the
+ bottom terminal 3.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44522112"></a>6. EasyMini</h2></div></div></div><div class="informalfigure"><div class="mediaobject"><table border="0" summary="manufactured viewport for HTML img" style="cellpadding: 0; cellspacing: 0;" width="495"><tr><td><img src="easymini-top.jpg" width="495"></td></tr></table></div></div><p>
+ EasyMini is built on a 0.8 inch by 1½ inch circuit board. It's
+ designed to fit in a 24mm coupler tube. The connectors and
+ screw terminals match TeleMini v2.0, so you can easily swap between
+ EasyMini and TeleMini.
+ </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44525968"></a>6.1. EasyMini Screw Terminals</h3></div></div></div><p>
+ EasyMini has two sets of four screw terminals on the end of the
+ board opposite the telemetry antenna. Using the picture
+ above, the top four have connections for the main pyro
+ circuit and an external battery and the bottom four have
+ connections for the apogee pyro circuit and the power
+ switch. Counting from the left, the connections are as follows:
+ </p><div class="table"><a name="idp44527376"></a><p class="title"><b>Table 4.6. EasyMini Connections</b></p><div class="table-contents"><table summary="EasyMini Connections" border="1"><colgroup><col align="center" class="Pin #"><col align="center" class="Pin Name"><col align="left" class="Description"></colgroup><thead><tr><th align="center">Terminal #</th><th align="center">Terminal Name</th><th align="center">Description</th></tr></thead><tbody><tr><td align="center">Top 1</td><td align="center">Main -</td><td align="left">Main pyro channel connection to pyro circuit</td></tr><tr><td align="center">Top 2</td><td align="center">Main +</td><td align="left">Main pyro channel common connection to battery +</td></tr><tr><td align="center">Top 3</td><td align="center">Battery +</td><td align="left">Positive external battery terminal</td></tr><tr><td align="center">Top 4</td><td align="center">Battery -</td><td align="left">Negative external battery terminal</td></tr><tr><td align="center">Bottom 1</td><td align="center">Apogee -</td><td align="left">Apogee pyro channel connection to pyro circuit</td></tr><tr><td align="center">Bottom 2</td><td align="center">Apogee +</td><td align="left">Apogee pyro channel common connection to
+ battery +</td></tr><tr><td align="center">Bottom 3</td><td align="center">Switch Output</td><td align="left">Switch connection to flight computer</td></tr><tr><td align="center">Bottom 4</td><td align="center">Switch Input</td><td align="left">Switch connection to positive battery terminal</td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44548352"></a>6.2. Using a Separate Pyro Battery with EasyMini</h3></div></div></div><p>
+ As described above, using an external pyro battery involves
+ connecting the negative battery terminal to the flight
+ computer ground, connecting the positive battery terminal to
+ one of the igniter leads and connecting the other igniter
+ lead to the per-channel pyro circuit connection.
+ </p><p>
+ To connect the negative pyro battery terminal to TeleMini
+ ground, connect it to the negative external battery
+ connection, top terminal 4.
+ </p><p>
+ Connecting the positive battery terminal to the pyro
+ charges must be done separate from EasyMini, by soldering
+ them together or using some other connector.
+ </p><p>
+ The other lead from each pyro charge is then inserted into
+ the appropriate per-pyro channel screw terminal (top
+ terminal 1 for the Main charge, bottom terminal 1 for the
+ Apogee charge).
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44551536"></a>6.3. Using an Active Switch with EasyMini</h3></div></div></div><p>
+ As explained above, an external active switch requires three
+ connections, one to the positive battery terminal, one to
+ the flight computer positive input and one to ground. Use
+ the negative external battery connection, top terminal 4 for
+ ground.
+ </p><p>
+ The positive battery terminal is available on bottom
+ terminal 4, the positive flight computer input is on the
+ bottom terminal 3.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44553632"></a>7. TeleMega</h2></div></div></div><div class="informalfigure"><div class="mediaobject"><table border="0" summary="manufactured viewport for HTML img" style="cellpadding: 0; cellspacing: 0;" width="495"><tr><td><img src="telemega-v1.0-top.jpg" width="495"></td></tr></table></div></div><p>
+ TeleMega is a 1¼ inch by 3¼ inch circuit board. It was
+ designed to easily fit in a 38mm coupler. Like TeleMetrum,
+ TeleMega has an accelerometer and so it must be mounted so that
+ the board is aligned with the flight axis. It can be mounted
+ either antenna up or down.
+ </p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44557600"></a>7.1. TeleMega Screw Terminals</h3></div></div></div><p>
+ TeleMega has two sets of nine screw terminals on the end of
+ the board opposite the telemetry antenna. They are as follows:
+ </p><div class="table"><a name="idp44558768"></a><p class="title"><b>Table 4.7. TeleMega Screw Terminals</b></p><div class="table-contents"><table summary="TeleMega Screw Terminals" border="1"><colgroup><col align="center" class="Pin #"><col align="center" class="Pin Name"><col align="left" class="Description"></colgroup><thead><tr><th align="center">Terminal #</th><th align="center">Terminal Name</th><th align="center">Description</th></tr></thead><tbody><tr><td align="center">Top 1</td><td align="center">Switch Input</td><td align="left">Switch connection to positive battery terminal</td></tr><tr><td align="center">Top 2</td><td align="center">Switch Output</td><td align="left">Switch connection to flight computer</td></tr><tr><td align="center">Top 3</td><td align="center">GND</td><td align="left">Ground connection for use with external active switch</td></tr><tr><td align="center">Top 4</td><td align="center">Main -</td><td align="left">Main pyro channel connection to pyro circuit</td></tr><tr><td align="center">Top 5</td><td align="center">Main +</td><td align="left">Main pyro channel common connection to battery +</td></tr><tr><td align="center">Top 6</td><td align="center">Apogee -</td><td align="left">Apogee pyro channel connection to pyro circuit</td></tr><tr><td align="center">Top 7</td><td align="center">Apogee +</td><td align="left">Apogee pyro channel common connection to battery +</td></tr><tr><td align="center">Top 8</td><td align="center">D -</td><td align="left">D pyro channel connection to pyro circuit</td></tr><tr><td align="center">Top 9</td><td align="center">D +</td><td align="left">D pyro channel common connection to battery +</td></tr><tr><td align="center">Bottom 1</td><td align="center">GND</td><td align="left">Ground connection for negative pyro battery terminal</td></tr><tr><td align="center">Bottom 2</td><td align="center">Pyro</td><td align="left">Positive pyro battery terminal</td></tr><tr><td align="center">Bottom 3</td><td align="center">Lipo</td><td align="left">
+ Power switch output. Use to connect main battery to
+ pyro battery input
+ </td></tr><tr><td align="center">Bottom 4</td><td align="center">A -</td><td align="left">A pyro channel connection to pyro circuit</td></tr><tr><td align="center">Bottom 5</td><td align="center">A +</td><td align="left">A pyro channel common connection to battery +</td></tr><tr><td align="center">Bottom 6</td><td align="center">B -</td><td align="left">B pyro channel connection to pyro circuit</td></tr><tr><td align="center">Bottom 7</td><td align="center">B +</td><td align="left">B pyro channel common connection to battery +</td></tr><tr><td align="center">Bottom 8</td><td align="center">C -</td><td align="left">C pyro channel connection to pyro circuit</td></tr><tr><td align="center">Bottom 9</td><td align="center">C +</td><td align="left">C pyro channel common connection to battery +</td></tr></tbody></table></div></div><br class="table-break"></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44595104"></a>7.2. Using a Separate Pyro Battery with TeleMega</h3></div></div></div><p>
+ TeleMega provides explicit support for an external pyro
+ battery. All that is required is to remove the jumper
+ between the lipo terminal (Bottom 3) and the pyro terminal
+ (Bottom 2). Then hook the negative pyro battery terminal to ground
+ (Bottom 1) and the positive pyro battery to the pyro battery
+ input (Bottom 2). You can then use the existing pyro screw
+ terminals to hook up all of the pyro charges.
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44596704"></a>7.3. Using Only One Battery With TeleMega</h3></div></div></div><p>
+ Because TeleMega has built-in support for a separate pyro
+ battery, if you want to fly with just one battery running
+ both the computer and firing the charges, you need to
+ connect the flight computer battery to the pyro
+ circuit. TeleMega has two screw terminals for this—hook a
+ wire from the Lipo terminal (Bottom 3) to the Pyro terminal
+ (Bottom 2).
+ </p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="idp44598624"></a>7.4. Using an Active Switch with TeleMega</h3></div></div></div><p>
+ As explained above, an external active switch requires three
+ connections, one to the positive battery terminal, one to
+ the flight computer positive input and one to ground.
+ </p><p>
+ The positive battery terminal is available on Top terminal
+ 1, the positive flight computer input is on Top terminal
+ 2. Ground is on Top terminal 3.
+ </p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44600672"></a>8. Flight Data Recording</h2></div></div></div><p>
+ Each flight computer logs data at 100 samples per second
+ during ascent and 10 samples per second during descent, except
+ for TeleMini v1.0, which records ascent at 10 samples per
+ second and descent at 1 sample per second. Data are logged to
+ an on-board flash memory part, which can be partitioned into
+ several equal-sized blocks, one for each flight.
+ </p><div class="table"><a name="idp44602080"></a><p class="title"><b>Table 4.8. Data Storage on Altus Metrum altimeters</b></p><div class="table-contents"><table summary="Data Storage on Altus Metrum altimeters" border="1"><colgroup><col align="center" class="Device"><col align="center" class="Bytes per sample"><col align="center" class="Total storage"><col align="center" class="Minutes of full-rate"></colgroup><thead><tr><th align="center">Device</th><th align="center">Bytes per Sample</th><th align="center">Total Storage</th><th align="center">Minutes at Full Rate</th></tr></thead><tbody><tr><td align="center">TeleMetrum v1.0</td><td align="center">8</td><td align="center">1MB</td><td align="center">20</td></tr><tr><td align="center">TeleMetrum v1.1 v1.2</td><td align="center">8</td><td align="center">2MB</td><td align="center">40</td></tr><tr><td align="center">TeleMetrum v2.0</td><td align="center">16</td><td align="center">8MB</td><td align="center">80</td></tr><tr><td align="center">TeleMini v1.0</td><td align="center">2</td><td align="center">5kB</td><td align="center">4</td></tr><tr><td align="center">TeleMini v2.0</td><td align="center">16</td><td align="center">1MB</td><td align="center">10</td></tr><tr><td align="center">EasyMini</td><td align="center">16</td><td align="center">1MB</td><td align="center">10</td></tr><tr><td align="center">TeleMega</td><td align="center">32</td><td align="center">8MB</td><td align="center">40</td></tr></tbody></table></div></div><br class="table-break"><p>
+ The on-board flash is partitioned into separate flight logs,
+ each of a fixed maximum size. Increase the maximum size of
+ each log and you reduce the number of flights that can be
+ stored. Decrease the size and you can store more flights.
+ </p><p>
+ Configuration data is also stored in the flash memory on
+ TeleMetrum v1.x, TeleMini and EasyMini. This consumes 64kB
+ of flash space. This configuration space is not available
+ for storing flight log data. TeleMetrum v2.0 and TeleMega
+ store configuration data in a bit of eeprom available within
+ the processor chip, leaving that space available in flash for
+ more flight data.
+ </p><p>
+ To compute the amount of space needed for a single flight, you
+ can multiply the expected ascent time (in seconds) by 100
+ times bytes-per-sample, multiply the expected descent time (in
+ seconds) by 10 times the bytes per sample and add the two
+ together. That will slightly under-estimate the storage (in
+ bytes) needed for the flight. For instance, a TeleMetrum v2.0 flight spending
+ 20 seconds in ascent and 150 seconds in descent will take
+ about (20 * 1600) + (150 * 160) = 56000 bytes of storage. You
+ could store dozens of these flights in the on-board flash.
+ </p><p>
+ The default size allows for several flights on each flight
+ computer, except for TeleMini v1.0, which only holds data for a
+ single flight. You can adjust the size.
+ </p><p>
+ Altus Metrum flight computers will not overwrite existing
+ flight data, so be sure to download flight data and erase it
+ from the flight computer before it fills up. The flight
+ computer will still successfully control the flight even if it
+ cannot log data, so the only thing you will lose is the data.
+ </p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44629504"></a>9. Installation</h2></div></div></div><p>
+ A typical installation involves attaching
+ only a suitable battery, a single pole switch for
+ 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
+ batteries as long as they supply between 4 and 12 volts.
+ </p><p>
+ The battery connectors are a standard 2-pin JST connector and
+ match batteries sold by Spark Fun. 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
+ generally reversed from the batteries used by Altus Metrum
+ products. In particular, the Tenergy batteries supplied for use
+ in Featherweight flight computers are not compatible with Altus
+ Metrum flight computers or battery chargers. <span class="emphasis"><em>Check
+ polarity and voltage before connecting any battery not purchased
+ from Altus Metrum or Spark Fun.</em></span>
+ </p><p>
+ By default, we use the unregulated output of the battery directly
+ to fire ejection charges. This works marvelously with standard
+ low-current e-matches like the J-Tek from MJG Technologies, and with
+ Quest Q2G2 igniters. However, if you want or need to use a separate
+ pyro battery, check out the “External Pyro Battery” section in this
+ manual for instructions on how to wire that up. The altimeters are
+ designed to work with an external pyro battery of no more than 15 volts.
+ </p><p>
+ Ejection charges are wired directly to the screw terminal block
+ 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.
+ </p><p>
+ 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.
+ </p><p>
+ 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
+ use off-board external antennas instead. In this case, you can
+ replace the stock UHF antenna wire with an edge-launched SMA connector,
+ 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.
+ </p></div></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="idp44636240"></a>Chapter 5. System Operation</h1></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl class="toc"><dt><span class="section"><a href="#idp44636880">1. Firmware Modes </a></span></dt><dt><span class="section"><a href="#idp44705168">2. GPS </a></span></dt><dt><span class="section"><a href="#idp44707952">3. Controlling An Altimeter Over The Radio Link</a></span></dt><dt><span class="section"><a href="#idp44719248">4. Ground Testing </a></span></dt><dt><span class="section"><a href="#idp44722000">5. Radio Link </a></span></dt><dt><span class="section"><a href="#idp44726000">6. APRS</a></span></dt><dt><span class="section"><a href="#idp44747968">7. Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#idp44749888">7.1. Radio Frequency</a></span></dt><dt><span class="section"><a href="#idp44751936">7.2. Callsign</a></span></dt><dt><span class="section"><a href="#idp44753472">7.3. Telemetry/RDF/APRS Enable</a></span></dt><dt><span class="section"><a href="#idp44754768">7.4. APRS Interval</a></span></dt><dt><span class="section"><a href="#idp44756240">7.5. Apogee Delay</a></span></dt><dt><span class="section"><a href="#idp44758832">7.6. Apogee Lockout</a></span></dt><dt><span class="section"><a href="#idp44760560">7.7. Main Deployment Altitude</a></span></dt><dt><span class="section"><a href="#idp44762256">7.8. Maximum Flight Log</a></span></dt><dt><span class="section"><a href="#idp44764400">7.9. Ignite Mode</a></span></dt><dt><span class="section"><a href="#idp44766512">7.10. Pad Orientation</a></span></dt><dt><span class="section"><a href="#idp44768208">7.11. Configurable Pyro Channels</a></span></dt></dl></dd></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp44636880"></a>1. Firmware Modes </h2></div></div></div><p>