From c871dd92a548e6af1e14d8866e01dda37d129747 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Sat, 13 Sep 2014 12:28:41 -0600 Subject: update docs --- AltOS/doc/micropeak.html | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) (limited to 'AltOS/doc/micropeak.html') diff --git a/AltOS/doc/micropeak.html b/AltOS/doc/micropeak.html index f443112..5fe70f9 100644 --- a/AltOS/doc/micropeak.html +++ b/AltOS/doc/micropeak.html @@ -1,4 +1,4 @@ -MicroPeak Owner's Manual

MicroPeak Owner's Manual

A recording altimeter for hobby rocketry

Keith Packard

Copyright © 2014 Bdale Garbee and Keith Packard

+MicroPeak Owner's Manual

MicroPeak Owner's Manual

A recording altimeter for hobby rocketry

Keith Packard

Copyright © 2014 Bdale Garbee and Keith Packard

Acknowledgements

+

Acknowledgements

Thanks to John Lyngdal for suggesting that we build something like this.

Have fun using these products, and we hope to meet all of you @@ -33,7 +33,7 @@ NAR Keith Packard, KD7SQG
NAR #88757, TRA #12200
      

-

Table of Contents

1. Quick Start Guide
2. Handling Precautions
3. The MicroPeak USB adapter
1. Installing the MicroPeak software
2. Downloading Micro Peak data
3. Analyzing MicroPeak Data
3.1. MicroPeak Graphs
3.2. MicroPeak Flight Statistics
3.3. Raw Data
3.4. Configuring the Graph
4. Setting MicroPeak Preferences
4. Technical Information
1. Barometric Sensor
2. Micro-controller
3. Lithium Battery
4. Atmospheric Model
5. Mechanical Considerations
6. On-board data storage
7. MicroPeak Programming Interface

List of Tables

4.1. MicroPeak EEPROM Data Storage

Chapter 1. Quick Start Guide

+

Table of Contents

1. Quick Start Guide
2. Handling Precautions
3. The MicroPeak USB adapter
1. Installing the MicroPeak software
2. Downloading Micro Peak data
3. Analyzing MicroPeak Data
3.1. MicroPeak Graphs
3.2. MicroPeak Flight Statistics
3.3. Raw Data
3.4. Configuring the Graph
4. Setting MicroPeak Preferences
4. Technical Information
1. Barometric Sensor
2. Micro-controller
3. Lithium Battery
4. Atmospheric Model
5. Mechanical Considerations
6. On-board data storage
7. MicroPeak Programming Interface

List of Tables

4.1. MicroPeak EEPROM Data Storage

Chapter 1. Quick Start Guide

MicroPeak is designed to be easy to use. Requiring no external components, flying takes just a few steps

  • @@ -84,7 +84,7 @@ NAR Recover the data. Turn MicroPeak off and then back on. MicroPeak will blink out the maximum height for the last flight. Turn MicroPeak back off to conserve battery power. -

Chapter 2. Handling Precautions

+

Chapter 2. Handling Precautions

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 @@ -114,12 +114,12 @@ NAR As with all other rocketry electronics, Altus Metrum altimeters must be protected from exposure to corrosive motor exhaust and ejection charge gasses. -

Chapter 3. The MicroPeak USB adapter

Table of Contents

1. Installing the MicroPeak software
2. Downloading Micro Peak data
3. Analyzing MicroPeak Data
3.1. MicroPeak Graphs
3.2. MicroPeak Flight Statistics
3.3. Raw Data
3.4. Configuring the Graph
4. Setting MicroPeak Preferences

+

Chapter 3. The MicroPeak USB adapter

Table of Contents

1. Installing the MicroPeak software
2. Downloading Micro Peak data
3. Analyzing MicroPeak Data
3.1. MicroPeak Graphs
3.2. MicroPeak Flight Statistics
3.3. Raw Data
3.4. Configuring the Graph
4. Setting MicroPeak Preferences

MicroPeak stores barometric pressure information for the first 48 seconds of the flight in on-board non-volatile memory. The contents of this memory can be downloaded to a computer using the MicroPeak USB adapter. -

1. Installing the MicroPeak software

+

1. Installing the MicroPeak software

The MicroPeak application runs on Linux, Mac OS X and Windows. You can download the latest version from http://altusmetrum.org/AltOS. @@ -128,7 +128,7 @@ NAR be installed. A compatible version of this driver is included with the MicroPeak application, but you may want to download a newer version from http://www.ftdichip.com/FTDrivers.htm. -

2. Downloading Micro Peak data

  • +

2. Downloading Micro Peak data

  • Plug the MicroPeak USB adapter in to your computer.

  • Start the MicroPeak application. @@ -161,7 +161,7 @@ NAR height, speed and acceleration values computed from the recorded barometric pressure data. See the next section for more details on that. -

3. Analyzing MicroPeak Data

+

3. Analyzing MicroPeak Data

The MicroPeak application can present flight data in the form of a graph, a collection of computed statistics or in tabular form. @@ -187,13 +187,13 @@ NAR Data tab) to a file, change the application Preferences, Close the current window or close all windows and Exit the application. -

3.1. MicroPeak Graphs

+

3.1. MicroPeak Graphs

Under the Graph tab, the height, speed and acceleration values are displayed together. You can zoom in on the graph by clicking and dragging to sweep out an area of interest. Right-click on the plot to bring up a menu that will let you save, copy or print the graph. -

3.2. MicroPeak Flight Statistics

+

3.2. MicroPeak Flight Statistics

The Statistics tab presents overall data from the flight. Note that the Maximum height value is taken from the minumum pressure captured in flight, and may be different from the @@ -201,13 +201,13 @@ NAR as fast as the recorded values, or because the true apogee occurred after the on-board memory was full. Each value is presented in several units as appropriate. -

3.3. Raw Data

+

3.3. Raw Data

A table consisting of the both the raw barometric pressure data and values computed from that for each recorded time. -

3.4. Configuring the Graph

+

3.4. Configuring the Graph

This selects which graph elements to show, and lets you switch between metric and imperial units -

4. Setting MicroPeak Preferences

+

4. Setting MicroPeak Preferences

The MicroPeak application has a few user settings which are configured through the Preferences dialog, which can be accessed from the File menu. @@ -241,7 +241,7 @@ NAR Note that MicroPeak shares a subset of the AltosUI preferences, so if you use both of these applications, change in one application will affect the other. -

Chapter 4. Technical Information

Table of Contents

1. Barometric Sensor
2. Micro-controller
3. Lithium Battery
4. Atmospheric Model
5. Mechanical Considerations
6. On-board data storage
7. MicroPeak Programming Interface

1. Barometric Sensor

+

Chapter 4. Technical Information

Table of Contents

1. Barometric Sensor
2. Micro-controller
3. Lithium Battery
4. Atmospheric Model
5. Mechanical Considerations
6. On-board data storage
7. MicroPeak Programming Interface

1. Barometric Sensor

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. @@ -257,7 +257,7 @@ NAR 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. -

2. Micro-controller

+

2. Micro-controller

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 @@ -268,7 +268,7 @@ NAR this mode, the chip consumes only .1μA of power. MicroPeak uses this mode once the flight has ended to preserve battery power. -

3. Lithium Battery

+

3. Lithium Battery

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 @@ -285,7 +285,7 @@ NAR battery with MicroPeak. If so, many stores carry CR1025 batteries as they are commonly used in small electronic devices such as flash lights. -

4. Atmospheric Model

+

4. Atmospheric Model

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 @@ -305,7 +305,7 @@ NAR 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. -

5. Mechanical Considerations

+

5. Mechanical Considerations

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 @@ -321,7 +321,7 @@ NAR 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. -

6. On-board data storage

+

6. On-board data storage

The ATtiny85 has 512 bytes of non-volatile storage, separate from the code storage memory. The MicroPeak firmware uses this to store information about the last completed @@ -335,7 +335,7 @@ NAR information captured with the MicroPeak USB adapter. It can also be read from MicroPeak through any AVR programming tool. -

Table 4.1. MicroPeak EEPROM Data Storage

AddressSize (bytes)Description
0x0004Average ground pressure (Pa)
0x0044Minimum flight pressure (Pa)
0x0082Number of in-flight samples
0x00a … 0x1fe2Instantaneous flight pressure (Pa) low 16 bits

+

Table 4.1. MicroPeak EEPROM Data Storage

AddressSize (bytes)Description
0x0004Average ground pressure (Pa)
0x0044Minimum flight pressure (Pa)
0x0082Number of in-flight samples
0x00a … 0x1fe2Instantaneous flight pressure (Pa) low 16 bits

All EEPROM data are stored least-significant byte first. The instantaneous flight pressure data are stored without the upper 16 bits of data. The upper bits can be reconstructed @@ -355,7 +355,7 @@ NAR 25°C. So, you can count on the pressure data being accurate, but speed or acceleration data computed from this will be limited by the accuracy of this clock. -

7. MicroPeak Programming Interface

+

7. MicroPeak Programming Interface

MicroPeak exposes a standard 6-pin AVR programming interface, but not using the usual 2x3 array of pins on 0.1" centers. Instead, there is a single row of tiny 0.60mm × -- cgit v1.2.3