Introducing MicroPeak by AltusMetrum

Micropeak is a barometric logging altimeter for precision model rocketry altitude measurements.

Production units are available from the Garbee and Garbee web store and Apogee Components

Data download is available using the MicroPeak USB adapter.


The MicroPeak manual is available in html and pdf formats.


The MicroPeak application runs on Linux, Mac OS X and Windows. It communicates with the MicroPeak USB adapter to download and analyze flight data. It's written in Java and offers the same functionality and interface on all three platforms. It uses the FTDI USB Serial drivers to communicate with the hardware. If you're running Mac OS X or Windows, a compatible version of those drivers is included with the software. You can also install a different from from the FTDI Driver page.

MicroPeak is part of the larger AltOS suite of software, which also includes a dedicated TeleGPS application.

Available Versions

MicroPeak version 1.6.8

Release Notes for Version 1.6.8

Release Notes for Version 1.6.8

Version 1.6.8 fixes a TeleMega and TeleMetrum v2.0 bug where the device could stop logging data and transmitting telemetry in flight. All TeleMega v1.0, v2.0 and TeleMetrum v2.0 users should update their flight firmware.

1. AltOS

AltOS fixes:

  • Fix STM32L DMA driver to work around STM32L SoC DMA priority issue t lock-up in the logging or radio code, either of which could stop data logging and telemetry.
  • Avoid having TeleBT battery status values smash telemetry packet data by holding a lock during both operations.
  • Don’t start reporting flight 0 when the log fills in flight.

AltOS changes:

  • Flash LEDS on all products briefly during power up so that they can be tested during production.

2. AltosUI, TeleGPS and AltosDroid Applications

AltosUI fixes:

  • Re-enable go/no-go entries after they’ve been disabled due to lack of data. If telemetry information is delayed when the Ui starts up, sometimes important fields would get disabled to never re-appear.
  • Deal with ground station failure better during Configure Ground Station operation by cleaning up pending operations.

MicroPeak version 1.6.5

Release Notes for Version 1.6.5

Release Notes for Version 1.6.5

Version 1.6.5 fixes a TeleMega and TeleMetrum v2.0 bug where the device would often stop logging data and transmitting telemetry in flight. All TeleMega v1.0, v2.0 and TeleMetrum v2.0 users should update their flight firmware.

1. AltOS

AltOS fixes:

  • Fix STM32L SPI driver to prevent lock-up in the logging or radio code, either of which could stop data logging and telemetry. Found and characterized by Chuck Haskin, who also tested the new firmware before release.

2. AltosUI, TeleGPS and AltosDroid Applications

AltosUI fixes:

  • Deliver firmward for TeleMega v2.0 and TeleBT v3.0 with Windows package.

MicroPeak version 1.6.4

Release Notes for Version 1.6.4

Release Notes for Version 1.6.4

Version 1.6.4 fixes a bluetooth communication problem with TeleBT v1.0 devices, along with some altosui and altosdroid minor nits. It also now ships firmware for some newer devices.

1. AltOS

AltOS fixes:

  • Fix hardware flow control on TeleBT v1.0. Hardware RTS/CTS doesn’t seem to work, switch from using the hardware to driving these pins with software.
  • Fix ARM USB drivers to deal with OS restarts. Needed to reset all USB-related state when the USB bus is reset. These fixes affect all STM32L, STM32F0 and LPC11U14 based devices.

2. AltosUI, TeleGPS and AltosDroid Applications

AltosUI, TeleGPS and AltosDroid New Features:

  • Automatically switch from meters or feet to kilometers or miles for distance units.
  • Add Monitor Idle mode to TeleGPS application.

AltosUI, TeleGPS and AltosDroid Fixes:

  • Abort map preloading when the preload map dialog is closed.
  • In AltosDroid, Don’t reconnect to last device if the user had disconnected it the last time the application was active.

3. Documentation

  • Mention TeleMega v2.0 in hardware specs table.
  • Document TeleGPS RF output in telegps manual.

MicroPeak version 1.6.3

Release Notes for Version 1.6.3

Release Notes for Version 1.6.3

Version 1.6.3 adds idle mode to AltosDroid and has bug fixes for our host software on desktops, laptops an android devices along with BlueTooth support for Windows.

1. AltOS

AltOS fixes:

  • Fix hardware flow control on TeleBT v3.0. RTS/CTS is wired backwards on this board, switch from using the hardware to driving these pins with software.

2. AltosUI and TeleGPS Applications

AltosUI and TeleGPS New Features:

  • Add BlueTooth support for Windows operating system. This supports connections to TeleBT over BlueTooth rather than just USB.

AltosUI and TeleGPS Fixes:

  • Change Java detection and install on Windows. Detection is now done by looking for the javaw.exe program, and installation by opening a browser on the web site.
  • Delay polling while the Fire Igniters is visible to allow for TeleMega to report back complete status over the radio.
  • Disallow changing RF calibration numbers in the configuration UI. There’s no good reason to change this from the field, and recovering is really hard if you haven’t written down the right number.
  • Fix USB device discovery on Mac OS X El Capitan. This makes the connected Altus Metrum USB devices appear again.
  • Fix acceleration data presented in MonitorIdle mode for TeleMetrum v2.0 flight computers.

3. AltosDroid

AltosDroid new features:

  • Monitor Idle mode. Check state of flight computer while in idle mode over the radio link
  • Fire Igniters. Remotely fire ignires for recovery system ground tests.
  • Remote reboot. Cause the flight computer to reboot over the radio link. This provides a method for switching the flight computer from idle to flight mode without needing to reach the power switch.
  • Configurable frequency menu. Change the set of available frequencies and provide more descriptive names.

AltosDroid bug fixes:

  • Don’t set target location if GPS hasn’t locked yet.
  • Fix saving target states so they can be reloaded when the application restarts. When the application is shut down and restarted, all previous target state information will be restored (including GPS position if available).
  • Fix crash on some Android devices for offline maps when changing the map scale or location.
  • Don’t require USB OTG support. This kept the latest AltosDroid from being offered on devices without USB device support, although it can work without that just fine using BlueTooth.
  • Don’t require bluetooth to be enabled. This allows the application to operate with USB devices or just show old data without turning on the bluetooth radio.
  • Recover old tracker positions when restarting application. This finally allows you to safely stop and restart the application without losing the last known location of any tracker.

4. Documentation

  • Document TeleMega and EasyMega additional pyro channel continuity audio alert pattern.

MicroPeak version 1.6.2

Release Notes for Version 1.6.2

Release Notes for Version 1.6.2

Bdale Garbee

Keith Packard

This document is released under the terms of the Creative Commons ShareAlike 3.0 license.

Version 1.6.2 includes support for our updated TeleMega v2.0 product and bug fixes in in the flight software for all our boards and ground station interfaces.

1. AltOS

AltOS New Features:

  • Add support for TeleMega v2.0 boards.
  • Add PWM servo driver. There’s no higher level code using this yet, but the driver allows testing of the TeleMega v2.0 servo output connector.

AltOS Fixes:

  • Slow down telemetry packets to allow receiver to keep up.

2. AltosUI and TeleGPS Applications

AltosUI and TeleGPS Fixes:

  • Fix post-flight orientation computation when processing TeleMega and EasyMega eeprom data files.
  • Capture complete eeprom data even when there are invalid entries in the data. This keeps reading eeprom contents and writing the associated .eeprom file when an error is detected.

3. Documentation

We spent a bunch of time trying to improve our documentation

  • HTML versions now have a table of contents on the left side.
  • EasyMini now has its own shorter manual.
  • Provide links between sections in each document.
  • Lots of minor rewriting and restructuring to avoid duplication of information

MicroPeak version 1.6.1

Version 1.6.1 includes support for our updated TeleBT v3.0 product and bug fixes in in the flight software for all our boards and ground station interfaces.

AltOS New Features

  • Add support for TeleBT v3.0 boards.

  • Add support for uncompressed APRS data, providing support for older APRS receivers. Uncompressed APRS data is less precise, takes more bandwidth and doesn't have integrated altitude data.

AltOS Fixes

  • Make TeleDongle and TeleBT more tolerant of data rate variations from transmitting devices.

AltosUI and TeleGPS New Features

  • Add map to Monitor Idle display. It's nice to be able to verify that maps are working, instead of needing to use Monitor Flight.

AltosUI Fixes

  • Fix frequency configuration to round values instead of truncate them, avoiding a common 1kHz error in the setting.

  • Turn the Windows stub into a more useful program that can launch the application with parameters so that file manager icons work more reliably.

  • Force KML export to use a C locale so that numbers are formatted with '.' instead of ',' for a decimal separator in non-US locales.

  • Preload map tiles based on distance rather than number of tiles; this means you get the same resolution covering the entire area, rather than having high resolution near the center and low resolution further away.

  • Allow configuration of frequency and callsign in Monitor Idle mode.

  • Fix layout weirdness when resizing windows on Windows. Windows shouldn't have giant blank spaces around the useful content anymore.

  • Fix layout weirdness when resizing windows on Windows. Windows shouldn't have giant blank spaces around the useful content anymore.

  • Use a longer filter for descent speed values. This should provide something more useful on the display, although it will take longer to respond to changes now.

  • Make Replay Flight run in realtime again. It had been set to run at 10x speed by mistake.

AltosDroid New Features

  • Add offline map support using mapping code from AltosUI.

  • Support TeleDongle (and TeleBT via USB) on devices supporting USB On-The-Go.

  • Display additional TeleMega pyro channel status in Pad tab.

  • Switch between metric and imperial units.

  • Monitor TeleBT battery voltage.

  • Track multiple devices at the same time, selecting between them with a menu or using the map.

  • Add hybrid, satellite and terrain map types.

AltosDroid Fixes

  • Use standard Android display conventions so that a menu button is available in the application title bar.

  • Adjust layout to work on large and small screens; shrinking the go/no-go lights in smaller environments to try and make everything visible.

  • Make voice announcements depend on current tab.

  • Compute adjustment to current travel direction while in motion towards rocket.

MicroPeak version 1.6

Version 1.6 includes support for our updated TeleDongle v3.0 product and bug fixes in in the flight software for all our boards and ground station interfaces.

AltOS New Features

  • Add support for TeleDongle v3.0 boards.

AltOS Fixes

  • Don't beep out the continuity twice by accident in idle mode. If the battery voltage report takes longer than the initialiation sequence, the igniter continuity would get reported twice.

  • Record all 32 bits of gyro calibration data in TeleMega and EasyMega log files. This fixes computation of the gyro rates in AltosUI.

  • Change TeleDongle LED usage. Green LED flashes when valid packet is received. Red LED flashes when invalid packet is received.

  • Replace LPC11U14 SPI driver with non-interrupt version. The interrupt code would occasionally wedge on long transfers if interrupts were blocked for too long. This affects all released TeleGPS products; if you have a TeleGPS device, you'll want to reflash the firmware.

AltosUI and TeleGPS New Features

  • Compute tilt angle from TeleMega and EasyMega log files. This duplicates the quaternion-based angle tracking code from the flight firmware inside the ground station software so that post-flight analysis can include evaluation of the tilt angle.

  • Shows the tool button window when starting with a data file specified. This means that opening a data file from the file manager will now bring up the main window to let you operate the whole application.

AltosUI Fixes

  • Show the 'Connecting' dialog when using Monitor Idle. Lets you cancel the Monitor Idle startup when connecting over the radio link.

  • Make 'Monitor Idle' work for TeleGPS devices when connected over USB. It's nice for testing without needing to broadcast over the radio.

  • Use different Windows API to discover USB devices. This works better on my Windows 7 box, and will be used if the older API fails to provide the necessary information.

  • Look in more places in the registry to try and identify the installed Java version on Windows. If you install the default 32-bit version of Windows on a 64-bit OS, the Java registry information is hiding \SOFTWARE\Wow6432Node for some reason.

  • Fix file association on Windows by searching for the javaw.exe program instead of assuming it is in %SYSTEMROOT%. This makes double-clicking on Altus Metrum data files in the file manager work correctly.

  • When replaying a file, put 'done' in the Age field when we reach the end of the file, instead of continuing to count forever.

  • In the Scan Channels code, wait for five seconds if we see any packet. This is needed because AltOS now sends the callsign, serial number and flight number only once every five seconds these days.

  • In the Scan Channels code, reset pending flight state information each time we change channels. This avoids having flight computers appear on multiple frequencies by accident.

MicroPeak version 1.5

Version 1.5 is a major release. It includes support for our new EasyMega product, new features and bug fixes in in the flight software for all our boards and the AltosUI ground station

AltOS New Features

  • Add support for EasyMega boards.

  • Make the APRS SSID be configurable. This lets you track different rockets on the same receiver without getting things mixed up.

  • Report extra pyro channel continuity state on EasyMega and TeleMega via the beeper. This lets you easily verify flight readiness on these boards after powering up the electronics on the rail.

  • Add lower telemetry data rates (2400 and 9600 bps) to increase telemetry radio range. This reduces the amount of data received as well as increasing battery consumption in the transmitter.

  • Change TeleGPS to have only a single log, and append new data to it rather than using seperate per-flight logs. This avoids accidentally filling up log storage by turning TeleGPS on/off several times.

AltOS Fixes

  • Increase the maximum range for altitude values from +/-32767m to +/-2147483647m, allowing the flight computers to function correctly above the 32km level.

  • Continuously test pyro firing conditions during delay stage, inhibiting the pyro channel if the test fails. This prevents firing pyro charges where the conditions were good before the delay, but become bad before the delay expires.

  • Allow negative numbers in pyro configuration values. This lets you specify things like descending speed or deceleration.

AltosUI and TeleGPS New Features

  • Support telemetry baud rate selection. Adds menus to the flight monitoring and configuration for baud rate selection.

  • Support APRS SSID configuration.

  • Integrate with file managers. This provides icons for all of our file types and associates our application with the files so that using a file manager to open a AltOS data file results in launching our application.

AltosUI Fixes

  • Make the 'Graph' button on the landed tab work again.

  • Make tests for Java on Windows a bit smarter, and also provide the user with the option to skip installing Java for cases where we just can't figure out what version is installed.

MicroPeak version 1.4.1

Version 1.4.1 is a minor release. It fixes install issues on Windows and provides the missing TeleMetrum V2.0 firmware. There aren't any changes to the firmware or host applications at all. All Windows users will want to upgrade to get the signed driver, but Mac and Linux users who do not need the TeleMetrum V2.0 firmware image will not need to upgrade.

Windows Install Fixes

  • Provide signed Windows driver files. This should avoid any need to disable driver signature checking on Windows 7 or 8.

  • Fix Java version detection and download. Previously, the installer would only look for Java 6 or 7 and insist on downloading its own Java bits if there was something else installed. Furthermore, the 64-bit Java link provided didn't work for anyone other than Keith, making it impossible to install AltOS on any machine with Java SE 8 installed.

Other Fixes

  • Include 1.4 firmware for TeleMetrum V2.0. None of the installers shipped this file. Now it's included in the AltOS packages for Linux, Mac and Windows.

  • Include Google Application Key for map downloading. The 1.4 release didn't have this key in the released version of the software, making map downloading fail for most people.

MicroPeak version 1.4

Version 1.4 is a major release. It includes support for our new TeleGPS product, new features and bug fixes in in the flight software for all our boards and the AltosUI ground station

AltOS New Features

  • Add support for TeleGPS boards.

  • Replace the 'dit dit dit' tones at startup with the current battery voltage, measured in tenths of a volt. This lets you check the battery voltage without needing telemetry, which is especially useful on EasyMini.

  • Change state beeping to "Farnsworth spacing", which means they're quite a bit faster than before, and so they take less time to send.

  • Make the beeper tone configurable, making it possible to distinguish between two Altus Metrum products in the same ebay.

  • Make the firing time for extra pyro channels configurable, allowing longer (or shorter) than the default 50ms. Only relevant for TeleMega at this time.

AltOS Fixes

  • Fix bug preventing the selection of the 'Flight State After' mode in pyro configuration.

  • Fix bug where erasing flights would reset the flight number to 2 on TeleMega and TeleMetrum v2.

  • Fix u-Blox GPS driver to mark course and speed data as being present.

AltosUI New Features

  • Add zooming and new content types (terrain and road maps) to map view. Change map storage format from PNG to Jpeg, which saves a huge amount of disk space. You will need to re-download all of your pre-loaded map images.

  • Add a distance measuring device to the maps view. Select this by using any button other than the left one, or by pressing shift or control on the keyboard while using the left button.

  • Add new 'Ignitor' tab to the flight monitor display for TeleMega's extra ignitors.

  • Increase the width of data lines in the graphs to make them easier to read.

  • Add additional ignitor firing marks and voltages to the graph so you can see when the ignitors fired, along with the ignitor voltages.

  • Add GPS course, ground speed and climb rate as optional graph elements.

AltosUI Fixes

  • When flashing new firmware, re-try opening the device as sometimes it takes a while for the underlying operating system to recognize that the device has rebooted in preparation for the flashing operation.

  • Hide Tilt Angle in ascent tab for devices that don't have a gyro.

  • Filter out speed and acceleration spikes caused by ejection charge firing when computing the maximum values. This provides a more accurate reading of those maximums.

  • Fix EasyMini voltage displays. Early EasyMini prototypes used a 3.0V regulator, and AltosUI still used that value as the basis of the computation. Production EasyMini boards have always shipped with a 3.3V regulator. Also, purple EasyMini boards sensed the battery voltage past the blocking diode, resulting in a drop of about 150mV from the true battery voltage. Compensate for that when displaying the value.

  • Display error message when trying to configure maximum flight log size while the flight computer still has flight data stored.

  • Handle TeleMetrum and TeleMini eeprom files generated with pre-1.0 firmware. Those ancient versions didn't report the log format, so just use the product name instead.

TeleGPS Application

  • New application designed for use with TeleGPS boards.

  • Shares code with AltosUI, mostly just trimmed down to focus on TeleGPS-related functions.

Documentation changes

  • Re-create the drill template images; they should print correctly from Firefox at least. Ship these as individual PDF files so they're easy to print.

  • Add a description of the 'Apogee Lockout' setting, which prevents the apogee charge from firing for a configurable amount of time after boost.

Hardware Features

  • Measure ground pressure and peak altitude pressure.
  • Logs 48 seconds of flight data
  • Orange LED blinks out maximum height in decimeters.
  • 18mm x 14mm. 1.9g including battery.
  • Power switch.

The CR1025 battery holder is mounted on the back side of the board, so there are no external wires or batteries to manage.

Software features

  • Saves last flight data to non-volatile memory.
  • Reports previous flight on power-on.
  • Automatically shuts down on landing to preserve battery.

Battery Holder

MicroPeak includes an integrated battery holder on the back side of the circuit board.

Developer View

Here's a close-up view of the hardware

  • Hardware Features

    • ATMEL ATtiny85 Microcontroller
      • 8K flash
      • 512B RAM
      • 512B EEPROM
      • SPI/I2C interface
    • Measurement Specialties MS5607 Micro Altimeter Module
      • Wide range — 120kPa to 1kPa (approximately -1500m to 31000m)
      • High precision — 2.4Pa resolution (approximately 20cm at sea level)
      • Factory calibrated.
    • CR1025 Lithium Battery
      • 30mAh. Runs MicroPeak for more than 40 hours on the pad or in flight
    • OSRAM LO T67K orange LED
    • Standard 6-pin AVR programming interface.
  • Software Features

    • Written in C
    • Samples pressure every 96ms
    • Delay 30s after power-on to finish airframe prep
    • Detect boost with 30m altitude change
    • Exponential averaging filter to minimize transient effects.
  • Tools Used

    • gEDA for schematic capture and PCB layout
    • GCC as an AVR cross-compiler
  • Licenses