+<h2 id="_easytimer">9. EasyTimer</h2>
+<div class="sectionbody">
+<div class="imageblock">
+<div class="content">
+<img src="easytimer.jpg" alt="easytimer" width="400">
+</div>
+<div class="title">Figure 8. EasyTimer Board</div>
+</div>
+<div class="paragraph">
+<p>EasyTimer is built on a 0.8 inch by 1½ inch circuit board. It’s
+designed to fit in a 24mm coupler tube.</p>
+</div>
+<div class="paragraph">
+<p>EasyTimer is designed to control events during ascent. It has
+an accelerometer and gyroscope that can measure acceleration
+and rotation and compute speed and tilt angle. EasyTimer has
+two pyro channels which can be configured to fire at various
+points during flight. Because EasyTimer has no barometric
+sensor, it cannot be used to fire recovery charges at apogee
+or during descent. EasyTimer is configured using the AltosUI
+application which is available for Linux, Mac OS X and Windows.</p>
+</div>
+<div class="sect2">
+<h3 id="_easytimer_screw_terminals">9.1. EasyTimer Screw Terminals</h3>
+<div class="paragraph">
+<p>EasyTimer has two sets of four screw terminals near
+one end of the board. Using the picture above, the top
+four have connections for pyro channel B and an
+external battery and the bottom four have connections
+for pyro circuit A and the power switch. Counting from
+the left, the connections are as follows:</p>
+</div>
+<table class="tableblock frame-all grid-all stretch">
+<caption class="title">Table 9. EasyTimer Screw Terminals</caption>
+<colgroup>
+<col style="width: 13.3333%;">
+<col style="width: 20%;">
+<col style="width: 66.6667%;">
+</colgroup>
+<thead>
+<tr>
+<th class="tableblock halign-left valign-top">Terminal #</th>
+<th class="tableblock halign-left valign-top">Terminal Name</th>
+<th class="tableblock halign-left valign-top">Description</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Top 1</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">B -</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Pyro channel B connection to pyro circuit</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Top 2</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">B +</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Pyro channel B common connection to battery +</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Top 3</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Battery +</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Positive external battery terminal</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Top 4</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Battery -</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Negative external battery terminal</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Bottom 1</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">A -</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Pyro channel A connection to pyro circuit</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Bottom 2</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">A +</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Pyro channel A common connection to battery +</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Bottom 3</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Switch Output</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Switch connection to flight computer</p></td>
+</tr>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Bottom 4</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Switch Input</p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">Switch connection to positive battery terminal</p></td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="sect2">
+<h3 id="_connecting_a_battery_to_easytimer">9.2. Connecting A Battery To EasyTimer</h3>
+<div class="paragraph">
+<p>There are two possible battery connections on
+EasyTimer. You can use either method; both feed
+through the power switch terminals.</p>
+</div>
+<div class="paragraph">
+<p>One battery connection is the standard Altus Metrum
+white JST plug. This mates with single-cell Lithium
+Polymer batteries sold by Altus Metrum.</p>
+</div>
+<div class="paragraph">
+<p>The other is a pair of screw terminals marked 'Battery
++' and 'Battery -'. Connect a battery from 4 to 12
+volts to these terminals, being careful to match polarity.</p>
+</div>
+</div>
+<div class="sect2">
+<h3 id="_charging_lithium_batteries_2">9.3. Charging Lithium Batteries</h3>
+<div class="paragraph">
+<p>Because EasyTimer allows for batteries other than the
+standard Altus Metrum Lithium Polymer cells, it cannot
+incorporate a battery charger circuit. Therefore, when
+using a Litium Polymer cell, you’ll need an external
+charger. These are available from Altus Metrum, or
+from Spark Fun.</p>
+</div>
+</div>
+<div class="sect2">
+<h3 id="_using_a_separate_pyro_battery_with_easytimer">9.4. Using a Separate Pyro Battery with EasyTimer</h3>
+<div class="paragraph">
+<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>
+</div>
+<div class="paragraph">
+<p>To connect the negative pyro battery terminal to EasyTimer
+ground, connect it to the negative external battery
+connection, top terminal 4.</p>
+</div>
+<div class="paragraph">
+<p>Connecting the switched positive battery terminal to the pyro
+charges must be done separate from EasyTimer, by soldering
+them together or using some other connector. Note that for
+safety, you must put a switch between the pyro battery and
+the rest of the circuit!</p>
+</div>
+<div class="paragraph">
+<p>The other lead from each pyro charge is then inserted into
+the appropriate per-pyro channel screw terminal (top
+terminal 1 for pyro channel A charge, bottom terminal 1 for
+pyro channel B charge).</p>
+</div>
+</div>
+<div class="sect2">
+<h3 id="_using_an_active_switch_with_easytimer">9.5. Using an Active Switch with EasyTimer</h3>
+<div class="paragraph">
+<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>
+</div>
+<div class="paragraph">
+<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>
+</div>
+<div class="sect1">
+<h2 id="_installation">10. Installation</h2>