determination.
</revremark>
</revision>
+ <revision>
+ <revnumber>1.3.2</revnumber>
+ <date>12 February 2014</date>
+ <revremark>
+ Add a "Download" button to the main window, which makes it
+ quicker to access the download function. Update the data
+ download documentation to reflect the new MicroPeak USB
+ adapter design. Monitor data during download to let you see
+ if the USB connection is working at all by showing the
+ characters received from the MicroPeak USB adapter.
+ </revremark>
+ </revision>
</revhistory>
</bookinfo>
- <acknowledgements>
+ <dedication>
+ <title>Acknowledgements</title>
<para>
Thanks to John Lyngdal for suggesting that we build something like this.
</para>
NAR #88757, TRA #12200
</literallayout>
</para>
- </acknowledgements>
+ </dedication>
<chapter>
<title>Quick Start Guide</title>
<para>
<para>
Finish preparing the rocket for flight. After the
previous flight data have been reported, MicroPeak waits for
- 30 seconds before starting to check for launch. This gives
+ one minute before starting to check for launch. This gives
you time to finish assembling the rocket. As those
activities might cause pressure changes inside the airframe,
MicroPeak might accidentally detect boost. If you need to do
- anything to the airframe after the 30 second window passes,
+ anything to the airframe after the one minute window passes,
make sure to be careful not to disturb the altimeter. The
- LED will remain dark during the 30 second delay, but after
+ LED will remain dark during the one minute delay, but after
that, it will start blinking once every 3 seconds.
</para>
</listitem>
<listitem>
<para>
- Fly the rocket. Once the rocket passes about 10m in height
- (32 feet), the micro-controller will record the ground
+ Fly the rocket. Once the rocket passes about 30m in height
+ (100 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
<itemizedlist>
<listitem>
<para>
- Connect the MicroPeak USB adapter to a USB cable and plug it
- in to your computer.
+ Plug the MicroPeak USB adapter in to your computer.
</para>
</listitem>
<listitem>
<para>
- Start the MicroPeak application, locate the File menu and
- select the Download entry.
+ Start the MicroPeak application and click on the Download
+ button at the top of the window.
</para>
</listitem>
<listitem>
<para>
- The MicroPeak USB adapter has a small phototransistor on the
- end of the board furthest from the USB connector. Locate
- this and place the LED on the MicroPeak right over
- it. Turn on the MicroPeak board and adjust the position
- until the blue LED on the MicroPeak USB adapter blinks in
- time with the orange LED on the MicroPeak board.
+ The MicroPeak USB adapter has a small phototransistor
+ under the hole in the center of the box.
+ Locate this, turn on the MicroPeak and place the orange LED on the MicroPeak
+ directly inside the hole, resting the MicroPeak itself on
+ the box. You should see the blue LED on the MicroPeak USB
+ adapter blinking in time with the orange LED on the
+ MicroPeak board itself.
</para>
</listitem>
<listitem>
</para>
<para>
Ground pressure is computed from an average of 16 samples,
- taken while the altimeter is at rest. Flight pressure is
- computed from a Kalman filter designed to smooth out any minor
- noise in the sensor values.
+ taken while the altimeter is at rest. The flight pressure used to
+ report maximum height is computed from a Kalman filter
+ designed to smooth out any minor noise in the sensor
+ values. The flight pressure recorded to non-volatile storage
+ is unfiltered, coming directly from the pressure sensor.
</para>
</section>
<section>
<section>
<title>Lithium Battery</title>
<para>
- The CR1025 battery used by MicroPeak holes 30mAh of power,
+ The CR1025 battery used by MicroPeak holds 30mAh of power,
which is sufficient to run for over 40 hours. Because
MicroPeak powers down on landing, run time includes only time
sitting on the launch pad or during flight.
<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
+ 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
+ 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
the resulting height is more accurate than either the ground
or apogee altitudes.
</para>
+ <para>
+ Because the raw pressure data is recorded to non-volatile
+ storage, you can use that, along with a more sophisticated
+ atmospheric model, to compute your own altitude values.
+ </para>
</section>
<section>
<title>Mechanical Considerations</title>
<para>
In addition to the data used to present the height of the last
flight, MicroPeak also stores barometric information sampled
- at regular intervals during the flight. This information can
- be extracted from MicroPeak through any AVR programming
+ at regular intervals during the flight. This is the
+ information captured with the MicroPeak USB adapter. It can
+ also be read from MicroPeak through any AVR programming
tool.
</para>
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projects / fw / altos / blobdiff