Flextrak F4-V6.1 Now Available!

Flextrak is a PiZero form factor STM F4 based High Altitude Balloon Tracker.

This board has a GPS receiver and radio transmitter designed for tracking high altitude balloon flights utilising a Raspberry Pi Zero W. An optional APRS board is available see related items.

You will get :

  • Flextrak F4-V6.2 Board
  • Battery holder + clip
  • 4 x 11mm Standoffs with screws to attach to the Pi+
  • Standard non stacking low profile header
  • RG174 Tail for making into a suitable antenna see this article.
  • Pi Zero W Board with Camera Cable (Camera not supplied - please order separately)
  • 32Gb SD Card preloaded with FlexTrak code.
  • External DS18B20 Temperature Sensor
  • GPS Stubby Antenna SMA-Male Straight 

The board is supplied with a 434,868 or 915 MHz LoRa radio transmitter   To track the location of flight you also need a suitable radio receiver, aerial and PC on the ground.  It can be tracked with a mobile phone connected to our LoRaGo device.

It features:

  • Efficient built-in power regulator providing run time of over 20 hours from 4 Energizer Lithium Ultimate AA cells (With no Pi - 11 hours with a Pi attached)
  • Highly sensitive UBlox GPS receiver suitable for altitudes up to 50km
  • Temperature sensor (Internal/External)
  • Battery voltage monitoring
  • Allows use of Raspberry Pi camera
  • Mounting holes and spacers for a solid connection to the Pi
  • Tracker will continue to work even if the Raspberry Pi fails. 
  • Flextrak can be used without attaching a Raspberry Pi at all.
  • Solid SMA connector for GPS antenna - no more snapped off antennas!

The open-source software provides these features:

  • Radio telemetry with GPS and sensor data using UKHAS standard
  • Radio image download using SSDV standard
  • Variable image size according to altitude
  • Stores full-definition images as well as smaller transmitted images
  • Automatically chooses better images for download
  • Supplied as github repository with instruction
  • Optional APRS transmission with additional hardware.
  • On board landing prediction

Weight Breakdown:


Flextrak Board      - 14g
Header + Standoffs  - 14g
Battery Holder+Clip - 13g
PiZeroW + Cable     - 14g
GPS Antenna         - 19g

Not supplied for information only:
Energizer L91 Lithium (AA)  - 14.5g x 4

Instruction Manual: Flextrak STM Manual

Flextrak settings can be programmed via Flextrak Config available here. To program the board connect a USB to serial connector to GND/ RX and TX only (Don't connect VCC). Can also be programmed directly from the attached Raspberry Pi.







Flextrak Raspberry Pi Kit

  • Brand: Uputronics
  • Product Code: HAB-FLEXTRAK
  • Availability: 59
  • £240.00

  • Ex Tax: £200.00

Available Options


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Tags: Flextrak Raspberry Pi Kit