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<title>Motor Testing: Static and In-Flight Motor Performance Testing</title>
<div class="details">
<span id="author" class="author">Bdale Garbee</span><br>
<span id="email" class="email"><a href="mailto:bdale@gag.com">bdale@gag.com</a></span><br>
-<span id="revnumber">version v1.9.12,</span>
-<span id="revdate">28 Oct 2022</span>
+<span id="revnumber">version v1.9.13,</span>
+<span id="revdate">19 Jan 2023</span>
</div>
<div id="toc" class="toc">
<div id="toctitle">Table of Contents</div>
</li>
<li><a href="#_installation">3. Installation</a>
<ul class="sectlevel2">
-<li><a href="#_power_switch_and_battery">3.1. Power Switch and Battery</a></li>
-<li><a href="#_pressure_sensor">3.2. Pressure Sensor</a></li>
+<li><a href="#_trigger_to_start_recording">3.1. Trigger to Start Recording</a></li>
+<li><a href="#_power_switch_and_battery">3.2. Power Switch and Battery</a></li>
+<li><a href="#_pressure_sensor">3.3. Pressure Sensor</a></li>
</ul>
</li>
<li><a href="#_operation">4. Operation</a></li>
<h2 id="_license">License</h2>
<div class="sectionbody">
<div class="paragraph">
-<p>Copyright © 2022 Bdale Garbee and Keith Packard</p>
+<p>Copyright © 2023 Bdale Garbee and Keith Packard</p>
</div>
<div class="paragraph">
<p>This document is released under the terms of the <a href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons ShareAlike 3.0 License</a></p>
<div class="sect1">
<h2 id="_installation">3. Installation</h2>
<div class="sectionbody">
+<div class="admonitionblock warning">
+<table>
+<tr>
+<td class="icon">
+<img src="./images/icons/warning.svg" alt="Warning">
+</td>
+<td class="content">
+Firmware versions prior to 1.9.13 used acceleration to detect
+launch. Starting with 1.9.13, the firmware switched to using
+pressure to trigger recording. Altus Metrum strongly recommends
+upgrading all EasyMotor boards to current firmware, the
+behavior of which is described here.
+</td>
+</tr>
+</table>
+</div>
+<div class="paragraph">
+<p>EasyMotor needs to be rigidly attached in the airframe, in any
+convenient orientation.</p>
+</div>
+<div class="sect2">
+<h3 id="_trigger_to_start_recording">3.1. Trigger to Start Recording</h3>
<div class="paragraph">
-<p>EasyMotor needs to be rigidly attached in the airframe, and the
-long axis of the circuit board needs to be aligned with the axis
-of flight. By default, the round beeper on the board should be
-“up” towards the nose cone, and the screw terminal strips should
-be “down” towards the fins and motor nozzle end of the rocket.</p>
+<p>Starting with firmware version 1.9.13, a pressure sensor must
+be attached, and pressure change is used to initiate and conclude
+data recording. Pressure and 3 axes of acceleration are recorded
+for later analysis.</p>
+</div>
+<div class="paragraph">
+<p>EasyMotor looks for a 50 psi rise in pressure from ambient to
+start recording. Recording stops when the pressure drops
+below 50 psi and shows variation of less than 30 psi for at
+least 10 seconds. These conditions are intended to capture all
+actual burn data including anomalies such as "chuffs".</p>
+</div>
</div>
<div class="sect2">
-<h3 id="_power_switch_and_battery">3.1. Power Switch and Battery</h3>
+<h3 id="_power_switch_and_battery">3.2. Power Switch and Battery</h3>
<div class="paragraph">
<p>In addition to the circuit board itself, EasyMotor needs
a power switch and battery to operate. Like many Altus
</div>
</div>
<div class="sect2">
-<h3 id="_pressure_sensor">3.2. Pressure Sensor</h3>
+<h3 id="_pressure_sensor">3.3. Pressure Sensor</h3>
<div class="paragraph">
<p>The primary motivation for designing EasyMotor was to have
a reliable way of recording motor chamber pressure during
</div>
<div id="footer">
<div id="footer-text">
-Version v1.9.12<br>
-Last updated 2022-10-28 23:33:07 -0600
+Version v1.9.13<br>
+Last updated 2023-01-19 23:18:22 -0700
</div>
</div>
</body>