AltOS is the name of Keith's firmware "operating system" for Altus Metrum products.

In addition to the firmware for hardware products like TeleMetrum, TeleMini, and TeleDongle, the AltOS source tree also includes AltosUI, which provides for flight monitoring, post-flight analysis, device configuration and firmware updating. AltosUI runs on Linux, Mac OS X and Windows. It's written in Java and offers the same functionality and interface on all three platforms. A small platform-specific library communicates with the USB interface on the Altus Metrum devices.

There are also Linux-specific tools that provide lower level access to the devices which are useful for developing firmware for the devices.

We maintain a list of launch site GPS coordinates. If your favorite launch site isn't included, please let us know!

Available Versions

There is a single manual for most Altus Metrum products, which is available in html and pdf formats.

We also have an AltOS internals document for programmers in html and pdf formats, and a document describing the AltOS over the radio protocol in html and pdf formats.

If you're running Windows 8, you should take a look at Installing AltosUI on Windows 8 which will help you install the operating system drivers needed to communicate with the USB hardware.

If you're running a recent version of Mac OS X, you'll probably need to read Installing AltosUI on Mac OS X. This describes how to get rid of the the 'App is damaged' messages and run the program.

Each available download includes AltosUI, documentation, and firmware updates for all current products.

Release Notes for Version 1.9.2

Version 1.9.2


  • Add support for TeleMega v4.0

  • Fix time wrapping issue with TeleLCO and TeleFire

AltosUI, TeleGPS, MicroPeak

  • Add column in AltosUI for IMU data from TeleMega and EasyMega


  • Allow sorting of trackers by call, serial, frequency or age

  • Offer selection of font sizes

  • Various bug fixes for older Android versions

Release Notes for Version 1.9.1

Version 1.9.1


  • Add support for TeleMetrum v3.0

  • Fix accel cal value when changing EasyMega v2.0 pad orientation

  • Correct EasyMega v2.0 magnetometer data axes

  • Fix EasyMega v2.0 idle monitor display of IMU data

  • Report all sensor failures at power-up time.

AltosUI, TeleGPS, MicroPeak

  • Display error message when attempting to graph unknown format file.

  • Make it possible to disable APRS once enabled.

  • Display some data for point near cursor in map tab.

  • Support upgrading devices from pre-1.8 firmware

  • Wait for Windows to prepare new devices during firmware upgrade. This should avoid the “COMxx: open failed” message.

Release Notes for Version 1.9

Version 1.9


  • Add support for EasyMega v2.0

  • Replace C library for ARM devices

  • Remove support for 8051-based devices and SDCC compiler

AltosUI, TeleGPS, MicroPeak

  • Select ROM images based on product name when reflashing

  • Fix TeleGPS v2 battery voltage display

Release Notes for Version 1.8.7

Release Notes for Version 1.8.7

Version 1.8.7

1. AltOS

  • Include TeleMega v3.0 firmware

2. AltosUI, TeleGPS, MicroPeak

  • Poll for new devices while Device dialog is displayed
  • Wait for device to re-appear when flashing new firmware
  • Fetch correct TeleBT v4.0 RF calibration values from web site when reflashing.
  • Change gyro headings in .csv files from x/y/z to roll/pitch/yaw
  • Add documentation about Packet Link mode
  • Add documentation about forcing TeleMini RF parameters to known values.
  • Create a proxy server for Google Maps to re-enable map images
  • Fix Java version info in all distributed jar files so that applications will run with standard Mac OS X Java.
  • Replace JavaApplicationStub for Mac OS X so that applications will run with Oracle Java.

Release Notes for Version 1.8.6

Release Notes for Version 1.8.6

Version 1.8.6

1. AltOS

  • Use maximum of 64 previous tilt values in pyro tilt tests
  • Eliminate 100m height requirement for coast detection
  • Change After Motor pyro check to be >= instead of ==
  • Change Time since Boost to be Time since launch.

2. AltosUI, TeleGPS

  • Clarify pyro test phrasing
  • Remove ascending/descending from pyro config UI
  • Fix accel calibration in Antenna Down mode
  • Add mag sensor reporting for TeleMega v3 idle monitoring.
  • Fix radio parameter saving at 2400 bps telmetry rate.

3. MicroPeak

  • Report altimeter-recorded maximum height value

Release Notes for Version 1.8.5

Release Notes for Version 1.8.5

Version 1.8.5 includes fixes to the ground software support for TeleBT v4, along with a few other minor updates.

1. AltOS

  • Fix startup beeps that indicate sensor failures.

2. AltosUI, TeleGPS

  • When updating device firmware, make sure selected firmware matches target device.
  • Correct Bluetooth device matching when looking for TeleBT devices.

Release Notes for Version 1.8.4

Release Notes for Version 1.8.4

Version 1.8.4 includes support for EasyMini version 2.0

1. AltOS

  • Support for EasyMini version 2.0 hardware.

Release Notes for Version 1.8.3

Release Notes for Version 1.8.3

Version 1.8.3 includes support for TeleMega version 3.0 along with two important flight computer fixes. This version also changes KML export data to make Tripoli Record reporting better and some updates to graph presentation and data downloading.

1. AltOS

1.1. AltOS New Features

  • Support for TeleMega version 3.0 hardware.

1.2. AltOS Bug Fixes

  • Ground testing EasyMega and TeleMega additional pyro channels could result in a sticky fired status which would prevent these channels from firing on future flights.
  • Corrupted flight log records could prevent future flights from capturing log data.
  • Fixed saving of pyro configuration that ended with Descending.

2. AltosUI and TeleGPS Applications

2.1. AltosUI New Features

  • Support for TeleMega version 3.0.
  • Graph lines have improved appearance to make them easier to distinguish. Markers may be placed at data points to show captured recorded data values.
  • Graphing offers the ability to adjust the smoothing of computed speed and acceleration data.
  • The download dialog now offers to graph new flights, checks for existing files to avoid overwriting data and reports if there are checksum errors in the downloaded data.

2.2. AltosUI/TeleGPS Bug Fixes

  • Restore TeleGPS tracking behavior.
  • Display flight computer call sign and serial number in Monitor Idle mode instead of ground station values.

2.3. AltosUI and TeleGPS Changes

  • KML export now reports both barometric and GPS altitude data to make it more useful for Tripoli record reporting.
  • CSV export now includes TeleMega/EasyMega pyro voltages and tilt angle.

Release Notes for Version 1.8.2

Release Notes for Version 1.8.2

Version 1.8.2 includes support for TeleGPS version 2.0 along with accelerometer recalibration support in AltosUI.

1.8.2 also contains a couple of minor fixes for AltosUI when analyzing saved data files.

1. AltOS

AltOS New Features

  • Support for TeleGPS version 2.0 hardware.

2. AltosUI and TeleGPS Applications

AltosUI and TeleGPS New Features

  • Support for TeleGPS version 2.0.
  • Accelerometer re-calibration user interface.

AltosUI and TeleGPS Bug Fixes

  • Prevent some crashes when reading older saved flight data for graphing or KML export.

Release Notes for Version 1.8.1

Release Notes for Version 1.8.1

Version 1.8.1 includes an important bug fix for Apogee Lockout operation in all flight computers. Anyone using this option must update firmware.

This release also contains a change in how flight computers with accelerometers deal with speeds around and above Mach 1. In previous versions, the flight computer would completely disregard the barometric sensor above 330m/s (around Mach 1). Now, the data from the barometric sensor is reduced in effect without ever going away entirely. This prevents early drogue deployment for flights which spend considerable time above Mach 1.

1.8.1 also contains a couple of minor fixes for AltosUI when analyzing saved data files.

1. AltOS

AltOS Bug Fixes

  • Handle time value wrapping in Apogee Lockout correctly. Without this, apogee lockout would sometimes prevent any drogue charge from firing.
  • Change Kalman filter on flight computers with accelerometer to continue using the barometric sensor even at high speeds to avoid unintentional drogue deployment during deceleration.

2. AltosUI and TeleGPS Applications

AltosUI New Features

  • Add new Huge font size to make text even bigger on high resolution monitors.

AltosUI Bug Fixes

  • Prevent some crashes when reading older saved flight data for graphing or KML export.
  • Load frequency preference at startup. The loading code was broken, so you’d see only the default frequencies.

Source Code

The latest source, which may include unreleased work in progress, is always available from in the project fw/altos.

We've gathered a few notes on buidling AltOS.

Future Plans

Bug reports, feature requests, and planning for AltOS releases happens on the Altus Metrum Trac Site.

A number of features are implemented or in process in the sources available in our publicly visible repository that are not part of the current stable release.

  • Motor characterization. Because TeleMetrum contains a high-resolution, high-frequency accelerometer, it is possible to take the data from that and compute an accurate thrust curve for the motor.

  • Comprehensive PDF and/or HTML -based flight report. Construct a complete report of the flight suitable for publication on the web that includes graphs of the flight and details about motor performance etc.

  • Publish flight data to the Altus Metrum web site. This will allow you to share your flight data with others, and let you download flights published by others.

There are any number of additions that could be made to this list; feel free to send along ideas that you’ve got. Of course, all of this software is licensed under the GNU General Public License, so you can get the source and hack on it in the comfort of your own home.

Platform Specific Notes


If you use Debian, you can simply install the 'altos' package from any Debian mirror, like so:

    apt-get update
    apt-get install altos

If you use some other distribution of Linux, then a Linux package of our second-generation Java bits that should run on any distribution with a modern Java version is also available. Unlike the Debian pacakge, which depends on various libraries already part of the Debian distribution, this package includes a "fat" jar file with all of the Java libraries that aren't part of the basic Java runtime environment included, so it should "just work" on any system with Java 6. Development and testing is done with OpenJDK 6, but current downloads from should be fine too.

If you'd rather build from source, our source tree includes documentation on how to build packages for various Linux systems such as Arch Linux, and the debian/ directory contains all the control files for building the Debian packages on other architectures or derivatives such as Ubuntu.

Bdale has also created a theme for GDM that he uses on his primary notebook, and the Simple Login Manager that he uses on all of his other machines and which is ideally suited for machines dedicated to AltOS ground station use. It includes a photo of a drag-race between nearly-identical rockets built by Keith and Bdale, that was the first time either of us gave TeleMetrum complete control of a rocket flight without some other backup! See the themes/ directory in the source tree (the themes are included in the Debian package).


A Mac OS X package that is compatible with versions 10.5 "Leopard" and later. The Mac operating system includes Java, and all Altus Metrum products show up as simple USB serial ports, so this should just work with no additional drivers or other dependency issues. Older versions of the Mac operating system, and even newer versions for PowerPC-based machines, come with Java version 5 or older, which is too old for use with Altus Metrum software. We know of no way to update the Java version other than upgrading to a newer operating system (for Intel based macs) or purchasing new hardware (for PowerPC based macs).

If you have trouble installing on a Mac, and are getting errors about the package being corrupt, you may not be configured to allow installation of software from arbitrary sources. One customer running 10.8.1 reported that he was able to work around this by going to "System Preferences", "Security & Privacy", "General", and then clicking the "Anywhere" radio button where it askes "Allow applications downloaded from:".


Our Windows package is known to work on at least some flavors of XP, Vista, and Windows 7 Enterprise. If you don't already have Java installed, download and install a current Java 6 version from first. Then download our installer and run it. Windows already has the required USB serial device driver, and our package should do the right things to bind it to our devices, but if you get a complaint about the device being unrecognized, try pointing to the copy of the telemetrum.inf file included in the package directory manually.

Note that on some Windows 7 systems, it may be necessary to install AltOS using 'compatibility mode'. You can set this mode by changing the properties of the installer .exe.


The firmware and associated software are licensed GPL version 2