doc: Add micropeak manual

Signed-off-by: Keith Packard <keithp@keithp.com>

2 files changed, 262 insertions, 2 deletions

diff --git a/doc/Makefile b/doc/Makefile
index 3e1626f0..53985431 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -12,8 +12,8 @@ RELNOTES=\
 	release-notes-1.1.html
 
 RELNOTES_XSL=$(RELNOTES:.html=.xsl)
-HTML=altusmetrum.html altos.html telemetry.html companion.html $(RELNOTES)
-PDF=altusmetrum.pdf altos.pdf telemetry.pdf companion.pdf
+HTML=altusmetrum.html altos.html telemetry.html companion.html micropeak.html $(RELNOTES)
+PDF=altusmetrum.pdf altos.pdf telemetry.pdf companion.pdf micropeak.pdf
 DOC=$(HTML) $(PDF)
 HTMLSTYLE=/usr/share/xml/docbook/stylesheet/docbook-xsl/html/docbook.xsl
 FOSTYLE=/usr/share/xml/docbook/stylesheet/docbook-xsl/fo/docbook.xsl
diff --git a/doc/micropeak.xsl b/doc/micropeak.xsl
new file mode 100644
index 00000000..2faef41c
--- /dev/null
+++ b/doc/micropeak.xsl
@@ -0,0 +1,260 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+  "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
+<book>
+  <title>MicroPeak Owner's Manual</title>
+  <subtitle>A peak-recording altimeter for hobby rocketry</subtitle>
+  <bookinfo>
+    <author>
+      <firstname>Keith</firstname>
+      <surname>Packard</surname>
+    </author>
+    <copyright>
+      <year>2012</year>
+      <holder>Bdale Garbee and Keith Packard</holder>
+    </copyright>
+    <legalnotice>
+      <para>
+        This document is released under the terms of the
+        <ulink url="http://creativecommons.org/licenses/by-sa/3.0/">
+          Creative Commons ShareAlike 3.0
+        </ulink>
+        license.
+      </para>
+    </legalnotice>
+    <revhistory>
+      <revision>
+	<revnumber>0.1</revnumber>
+	<date>29 October 2012</date>
+	<revremark>
+	  Initial release with preliminary hardware.
+	</revremark>
+      </revision>
+    </revhistory>
+  </bookinfo>
+  <acknowledgements>
+    <para>
+      Thanks to John Lyngdal for suggesting that we build something like this.
+    </para>
+    <para>
+      Have fun using these products, and we hope to meet all of you
+      out on the rocket flight line somewhere.
+      <literallayout>
+Bdale Garbee, KB0G
+NAR #87103, TRA #12201
+
+Keith Packard, KD7SQG
+NAR #88757, TRA #12200
+      </literallayout>
+    </para>
+  </acknowledgements>
+  <chapter>
+    <title>Quick Start Guide</title>
+    <para>
+      MicroPeak is designed to be easy to use. Requiring no external
+      components, flying takes just a few steps
+    </para>
+    <itemizedlist>
+      <listitem>
+	<para>
+	  Install the battery. Fit a CR1025 battery into the plastic
+	  carrier. The positive (+) terminal should be towards the more
+	  open side of the carrier. Slip the carrier into the battery
+	  holder with the positive (+) terminal facing away from the
+	  circuit board.
+	</para>
+      </listitem>
+      <listitem>
+	<para>
+	  Install MicroPeak in your rocket. This can be as simple as
+	  preparing a soft cushion of wadding inside a vented model payload
+	  bay. Wherever you mount it, make sure you protect the
+	  barometric sensor from corrosive ejection gasses as those
+	  will damage the sensor.
+	</para>
+      </listitem>
+      <listitem>
+	<para>
+	  Turn MicroPeak on. Slide the switch so that the actuator
+	  covers the '1' printed on the board. MicroPeak will report
+	  the maximum height of the last flight in decimeters using a
+	  sequence of flashes on the LED. A sequence of short flashes
+	  indicates one digit. A single long flash indicates zero. The
+	  height is reported in decimeters, so the last digit will be
+	  tenths of a meter. For example, if MicroPeak reports 5 4 4
+	  3, then the maximum height of the last flight was 544.3m, or
+	  1786 feet. After reporting the last flight, MicroPeak starts
+	  waiting for launch. It will flash once every three seconds
+	  in this mode.
+	</para>
+      </listitem>
+      <listitem>
+	<para>
+	  Fly the rocket. Once the rocket passes about 4m in height
+	  (13 feet), the micro-controller will record the ground
+	  pressure and track the pressure seen during the flight. In
+	  this mode, the LED flickers rapidly. When the rocket lands,
+	  and the pressure stabilizes, the micro-controller will record
+	  the minimum pressure pressure experienced during the flight,
+	  compute the height represented by the difference in air
+	  pressure and blink that value out on the LED. After that,
+	  MicroPeak powers down to conserve battery power.
+	</para>
+      </listitem>
+      <listitem>
+	<para>
+	  Recover the data. Turn MicroPeak off for a couple of seconds
+	  (to discharge the capacitors) and then back on. MicroPeak
+	  will blink out the maximum height for the last flight. Turn
+	  MicroPeak back off to conserve battery power.
+	</para>
+      </listitem>
+    </itemizedlist>
+  </chapter>
+  <chapter>
+    <title>Handling Precautions</title>
+    <para>
+      All Altus Metrum products are sophisticated electronic devices.  
+      When handled gently and properly installed in an air-frame, they
+      will deliver impressive results.  However, as with all electronic 
+      devices, there are some precautions you must take.
+    </para>
+    <para>
+      The CR1025 Lithium batteries have an
+      extraordinary power density.  This is great because we can fly with
+      much less battery mass... but if they are punctured
+      or their contacts are allowed to short, they can and will release their
+      energy very rapidly!
+      Thus we recommend that you take some care when handling MicroPeak
+      to keep conductive material from coming in contact with the exposed metal elements.
+    </para>
+    <para>
+      The barometric sensors used in MicroPeak is
+      sensitive to sunlight. Please consider this when
+      designing an installation, for example, in an air-frame with a
+      see-through plastic payload bay. Many model rockets with payload bays
+      use clear plastic for the payload bay. Replacing these with an opaque
+      cardboard tube, painting them, or wrapping them with a layer of masking
+      tape are all reasonable approaches to keep the sensor out of direct
+      sunlight.
+    </para>
+    <para>
+      The barometric sensor sampling ports must be able to "breathe",
+      both by not being covered by foam or tape or other materials that might
+      directly block the hole on the top of the sensor, and also by having a
+      suitable static vent to outside air.
+    </para>
+    <para>
+      As with all other rocketry electronics, Altus Metrum altimeters must 
+      be protected from exposure to corrosive motor exhaust and ejection 
+      charge gasses.
+    </para>
+  </chapter>
+  <chapter>
+    <title>Technical Information</title>
+    <section>
+      <title>Barometric Sensor</title>
+      <para>
+	MicroPeak uses the Measurement Specialties MS5607 sensor. This
+	has a range of 120kPa to 1kPa with an absolute accuracy of
+	150Pa and a resolution of 2.4Pa.
+      </para>
+      <para>
+	The pressure range corresponds roughly to an altitude range of
+	-1500m (-4900 feet) to 31000m (102000 feet), while the
+	resolution is approximately 20cm (8 inches) near sea level and
+	60cm (24in) at 10000m (33000 feet).
+      </para>
+      <para>
+	Ground pressure is computed from an average of 16 samples,
+	taken while the altimeter is at rest. Flight pressure is
+	computed from an exponential IIR filter designed to smooth out
+	transients caused by mechanical stress on the barometer.
+      </para>
+    </section>
+    <section>
+      <title>Micro-controller</title>
+      <para>
+	MicroPeak uses an Atmel ATtiny85 micro-controller. This tiny
+	CPU contains 8kB of flash for the application, 512B of RAM for
+	temporary data storage and 512B of EEPROM for non-volatile
+	storage of previous flight data.
+      </para>
+      <para>
+	The ATtiny85 has a low-power mode which turns off all of the
+	clocks and powers down most of the internal components. In
+	this mode, the chip consumes only .1μA of power. MicroPeak
+	uses this mode once the flight has ended to preserve battery
+	power.
+      </para>
+    </section>
+    <section>
+      <title>Lithium Battery</title>
+      <para>
+	The CR1025 battery used by MicroPeak holes 30mAh of power,
+	which is sufficient to run for over 15 hours. Because
+	MicroPeak powers down on landing, run time includes only time
+	sitting on the launch pad or during flight.
+      </para>
+      <para>
+	The large positive terminal (+) is usually marked, while the
+	smaller negative terminal is not. Make sure you install the
+	battery with the positive terminal facing away from the
+	circuit board where it will be in contact with the metal
+	battery holder. A small pad on the circuit board makes contact
+	with the negative battery terminal.
+      </para>
+      <para>
+	Shipping restrictions prevent us from including a CR1025
+	battery with MicroPeak. Many stores carry CR1025 batteries as
+	they are commonly used in small electronic devices such as
+	flash lights.
+      </para>
+    </section>
+    <section>
+      <title>Atmospheric Model</title>
+      <para>
+	MicroPeak contains a fixed atmospheric model which is used to
+	convert barometric pressure into altitude. The model was
+	converted into a 469-element piece wise linear approximation
+	which is then used to compute the altitude of the ground and
+	apogee. The difference between these represents the maximum
+	height of the flight.
+      </para>
+      <para>
+	The model assumes a particular set of atmospheric conditions,
+	which while a reasonable average cannot represent the changing
+	nature of the real atmosphere. Fortunately, for flights
+	reasonably close to the ground, the effect of this global
+	inaccuracy are largely canceled out when the computed ground
+	altitude is subtracted from the computed apogee altitude, so
+	the resulting height is more accurate than either the ground
+	or apogee altitudes.
+      </para>
+    </section>
+    <section>
+      <title>Mechanical Considerations</title>
+      <para>
+	MicroPeak is designed to be rugged enough for typical rocketry
+	applications. It contains two moving parts, the battery holder
+	and the power switch, which were selected for their
+	ruggedness.
+      </para>
+      <para>
+	The MicroPeak battery holder is designed to withstand impact
+	up to 150g without breaking contact (or, worse yet, causing
+	the battery to fall out). That means it should stand up to
+	almost any launch you care to try, and should withstand fairly
+	rough landings.
+      </para>
+      <para>
+	The power switch is designed to withstand up to 50g forces in
+	any direction. Because it is a sliding switch, orienting the
+	switch perpendicular to the direction of rocket travel will
+	serve to further protect the switch from launch forces.
+      </para>
+    </section>
+  </chapter>
+</book>
+<!--  LocalWords:  Altusmetrum MicroPeak
+-->