This is a GPS-based position tracker and logger. It uses the same GPS receiver and radio as our flight computers, but does not include pyro circuits. This allows the board to be small and light so that it will fit well anywhere you need a good GPS tracker.

TeleGPS firmware and related ground station software is part of the AltOS software suite on this site. A stripped-down ground station program specifically for use with TeleGPS is documented below.

These are photos of production version 1.0, which is substantially similar visually to the current production version.


The manual for TeleGPS is available in html and pdf formats.


The TeleGPS application runs on Linux, Mac OS X and Windows. 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.

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

Available Versions

Release Notes for Version 1.9.18

Version 1.9.18


  • Add support for EasyTimer V2. The new version of this product has on-board storage to log data during flight.

AltosUI & TeleGPS application

  • Add support for EasyTimer V2. This includes support for analyizing flight data from the on-board logs.

  • Allow on-board beepers to be disabled by setting the frequency to 0.

Release Notes for Version 1.9.17

Version 1.9.17


  • Fix TeleMini v3 Monitor Idle support

  • Support TeleMetrum v4.0 with uBlox-10 GPS module

  • Improve igniter reporting via the beeper.

AltosUI & TeleGPS application

  • Add support for EasyMini v3 Monitor Idle

Release Notes for Version 1.9.16

Version 1.9.16


  • Add TeleGPS v3.0 support

AltosUI & TeleGPS application

  • Add TeleGPS v3.0 support

Release Notes for Version 1.9.15

Version 1.9.15


  • Add TeleMega v6.0 support

  • Add TeleMetrum v4.0 support

  • Fix sign of IMU values for TeleMega v5 boards in the 'across' axis. This affects IMU acceleration and gyro reports for that axis, but has no effect on in-flight operation of the tilt computation.

Release Notes for Version 1.9.14

Version 1.9.14


  • Fix 1.9.13 regression in TeleLCO startup sequence that detects available TeleFire units.

Release Notes for Version 1.9.13

Version 1.9.13


  • Add option to beep max height in feet after landing

  • Fix APRS reports to be sent at the correct time and spacing.

  • Fix possible barometric sensor communication failure when the CPU is busy talking to the radio at the same time. This would cause loss of telemetry and failure to track the state of the rocket during flight. This was aggrevated by the APRS reports getting sent more often than they should.

  • Change EasyMotor v3 code to base logging on motor pressure rather than the accelerometer. This allows use of EasyMotor v3 in a static test stand.


  • Add support for configuring the units used to report height after landing on the beeper.

Release Notes for Version 1.9.12

Version 1.9.12


  • Add EasyMini v3.0 and EasyMotor v3.0 support

  • Fix TeleMetrum v2.0 configuration. Saving config would crash the board.


  • Add EasyMotor log parsing and graphing.

Release Notes for Version 1.9.11

Version 1.9.11


  • Make Apogee Delay work again.

  • Allow TX power to be limited to 10mW for compliance with some uses under UK regulations.

  • Fix numerous minor issues with 16- vs 32- bit time values.


  • Support M1-based Macs, follow AdoptOpenJDK to Adoptium


  • Handle Bluetooth permissions reliably.

  • Fix some screen rotation bugs.

Release Notes for Version 1.9.10

Version 1.9.10

This release contains a couple of bug fixes for ground station software.


  • Rework the windows DLL build to make AltosUI run on more instances of Windows 10.


  • Adapt to Android security changes which prevent AltosDroid from storing flights in /storage/emulated/0/AltusMetrum. Now, flights are stored in /storage/emulated/0/media/org.altusmetrum.AltosDroid/AltusMetrum instead. Also, AltosDroid will display an error message if flight data cannot be logged.

Release Notes for Version 1.9.9

Version 1.9.9

This release contains a critical bug fix for a problem introduced in version 1.9.8 for TeleMega and EasyMega boards. This problem occurs when using the stored configuration from 1.9.7 or earlier.

If you are running 1.9.8 or are upgrading from 1.9.8 on any version of TeleMega or EasyMega, you must reconfigure all pyro channels, recalibrate accelerometers, reset the APRS interval, adjust the beep tone and reset the pyro time.


  • Fix EasyMega and TeleMega upgrade process from 1.9.7 or earlier. 1.9.8 introduced larger delay values, which required modifying the configuration in-place, and the 1.9.8 version had a flaw which broke the pyro channel config and all of the config values beyond that in memory, including APRS interval, IMU accel calibation, beep tone and pyro time.

  • Fix TeleMega v5.0 mag sensor driver. This driver was quite broken due to developing it in the presence of the magnetic beeper on the board. Because of that beeper, the values this sensor records are not accurate. Fortunately, they are not used for controlling the flight.


  • Parse TeleMega v5.0 log files. A missing check in the code meant that the TeleMega v5.0 log files would cause an error when attempting to load them. Logs saved with AltosUI 1.9.8 were not affected, only the presentation of the data was broken.


User View

  • GPS tracker and logger
  • Offers custom digital telemetry, APRS and direction beacons
  • 70cm ham-band transceiver for telemetry downlink
  • High-dynamics GPS receiver for accurate tracking
  • Uses 3.7V Lithium Polymer battery.
  • 1.5 x 1.0 inch board designed to fit inside 29mm airframe coupler tube
  • 2MB on-board data logging flash
  • Built-in USB connection for configuration, data download and battery charging
  • 12.3g flight weight (including antenna, excluding any battery)

Developer View

  • Hardware Features
    • ST Micros STM32L151 ARM Cortex M3 based Microcontroller
      • TI CC1200 High Performance RF Transceiver for Narrowband Systems
    • uBlox Max 7Q GPS receiver
    • Built-in USB data download and battery charger connection
    • 2MB SPI flash
  • Software Features
    • Written mostly in C with some ARM assembler
    • Runs from on-chip flash, uses on-chip RAM, stores tracking data to flash memory part
  • Tools Used
    • gEDA for schematic capture and PCB layout
    • GCC compiler and source debugger
  • Licenses


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

The current hardware design files are available from in the project hw/telegps.

For those who don't have ready access to the gEDA suite, here are pdf snapshots of the design for Production PCB version 2.0:

History of TeleGPS