Thursday 28 December 2023

IGC Validation and New Firmware

It has been while since my last update. A few things have been happening behind the scenes. This post announces IGC validation for the Bluefly and describes the latest firmware and software.  

IGC Validation

I am happy to announce that validation of Bluefly XBF signed files is now officially supported by the FAI-CIVL open validation server. Validation for IGC files is required for some competitions, and importantly for many of us is used by XCContest. 

A few years ago some models of the Bluefly got IGC tracklog recording. But until October this year the only way to validate to the file was to download it via GPS Dump as described in this post

For the technically minded, the IGC signing process is handled in the hardware. The IGC file data is stored in onboard NOR Flash memory using a proprietary file format as the $GPGGA and $GNGGA sentences are read from the onboad GPS and processed into B records. The IGC file is signed on the Bluefly using the XBF protocol when recording has stopped (when the Bluefly is shut down).

The Bluefly IGC file can be downloaded using the BFVDesktop application available from using the procedure describe in this post.  Users can connect the Bluefly to a PC and it appears as a serial port. The BFVDesktop application communicates with the Bluefly using commands over the serial port, including commands to list files and download them individually. Users can also format the NOR Flash memory.

The following models include IGC recording. These are all based on the same codebase and use the same IGC format and memory protocol, with the relevant updates to the IGC header to reflect hardware and firmware versions.

  • BlueFlyVario_Bluetooth_GPS_IGC_v23 (current model released May 2023)
  • BlueFlyVario_USB_TTL_GPS_IGC_v22 (current model released May 2022)
  • BlueFlyVario_Bluetooth_GPS_IGC_v22 (previous model released May 2022)
  • BlueFlyVario_Bluetooth_GPS_IGC_v12.3 (previous model released June 2021)
If you want to do validation separately from the open validation server you can download vali-xbf.exe.

M70 Firmware Update (v22 and v23 models)

I have also recently completed testing new firmware for the v22 and v23 models. I only recommend updating firmware if there is a new feature you want to try or if you are not happy with the performance of your vario. 

The key changes are:

  • Updated the $XCTOD sentence used to send voltage and temperature data from the Bluefly to XCTrack
    • Adds a checksum to make it more robust (see here for more explanation). 
    • Fixes a battery voltage error from some firmware versions.
  • Added a new beepDutyCycle hardware setting. You might want to use this to change the nature of the Bluefly beeps, or perhaps to prolong the battery life. 
    • By default when the Bluefly beeps in lift the ratio of beep to silence is 1:1. 
    • It beeps faster when you go up, but still the length of the beep and silence is the same. 
    • By adjusting the beep duty cycle you can shorten the beep to silence ratio. 
    • Start by experimenting with the setting at 0.5 or 0.25.
  • Rebuilt the IGC Flash memory writing code. 
    • For some combination of device and Bluefly there were intermittent errors associated with the periodic writing of track data to the onboard flash memory. 
    • Flash writing tasks now run in the background. 
The firmware files are here:

Follow the firmware update procedures described in this earlier blog post. I recommend resetting default settings and formatting IGC memory after you have done a firmware update. 

BFVDesktop application updated

You can also get the latest BFVDesktop application here: This includes:
  • The new beepDutyCycle setting.
  • An included script for running the application on Mac OS. You should read this knowledge base article for more information. 

Saturday 27 May 2023

BlueFlyVario v23 models released

Today we announce the release of two new Bluefly v23 models. These have actually been shipping for a few weeks now. The BlueFlyVario_Bluetooth_v23 is the latest version of the classic Bluefly. The BlueFlyVario_Bluetooth_GPS_IGC_v23 includes an onboard GPS and IGC tracklog recording. 

The new Bluefly v23 models look the same.

What is new?

These models are an evolution of the v22 models. The main processor is the same and the firmware is almost exactly the same as the v22. Firmware updates will continue to be made for both v22 and v23. 

The main changes are:

  • USB-C charging and serial port interface. The shift from micro-USB to USB-C reflects the standard most devices are adopting, and the physical port is more robust. 
  • The GPS version now uses the L96 GPS module instead of the XA1110. The latter is no longer available and the L96 has better performance, in my experience. 
    • The good news is that the GPS is now entirely inside the case - no more protruding antenna.
    • The downside to this GPS module is that the chip antenna is very sensitive to placement of other components. This was overcome in the v23 model by putting the GPS module on a small board and raising it just a few mm further away from the battery. The end result is a much cleaner layout, albeit that the manufacturing time per device is a bit longer. 
BlueFlyVario_Bleutooth_GPS_IGC_v23 internals, showing GPS module antenna slightly above the base board.
What is in the box?

Both models are shipped fully assembled and ready to use. Simply remove the tape and cover protecting the clear button, press the button and your vario should come to life. Some tips:

Monday 6 February 2023

Firmware Update x68

The latest firmware for all v22 models has been uploaded

Changes include:

  • Fixed a bug with button performance. The button was not as responsive to a press as it should be during lift or sink. 
  • Fixed a bug for GPS models that very occasionally interleaved the PRS and B Record sentence, which might have caused issues for XCTrack users who configured to use external GPS. 

Follow the firmware update procedures described in this earlier blog post