FxWind is a wind measurement tool for FAI Aeromodeling contests. In the FAI rules for different contest classes like F3B, F3J, F3K, etc. there are defined rules under which wind conditions a contest can take place and under which conditions a contest has to be interrupted. FxWind will help you to comply with these competition rules.
All HW and SW Parts are published as open source and could be used to build your own measurement tool.
Feel free to open an issue or participate in the development by opening a pull request.
- Battery powered. Last one complete competition day of at least 12 hours
- Recharchable by USB-C in 2-3 hours
- Additional Backup Power by USB-C
- Magnetic connection between sensor and display, no wiring
- 3D Printed parts for Microcontroller and accessories
- Simple Alloy tube as base rig
- Waterproof
- Logging of Windspeed and Datetime on SD-Card for auditabilty, traceabiliy and possible complaints
- 1s Sampling rate
- Wifi or Accesspoint connection to display the windspeed conditions on a webpage
- Time synchronisation with NTP server and local backup of date and time with a Real Time Clock (RTC)
- Touch display with current windspeed and the needed ranges
- Visualisation of regions in the time plot where the wind thresholds has exceeded
- Accustic alarm if the condition are met to interrupt a contest
You can find the operation manual on the following link Operation Manual
The windspeed sensor and the controller with display are mounted on a alloy tube which has the specified height of 2m above the ground. The original controller case of the M5Tough device is replaced by a 3D printed part which contains the rechargeable battery, the magnetic connector, the USB-C port and the magnetic Pogo Pin connector for the electric connection to the wind sensor. The controller and USB-C Port is sealed with an O-ring to ensure the waterproof design. The alloy tube is splitted into two parts for better transportability and could be sticked together with a tube connector.
| Part | Quantity | Description | Link |
|---|---|---|---|
| M5Tough | 1 | Microcontroller with Touchscreen | https://docs.m5stack.com/en/core/tough |
| 1S 2000mAh Lipo | 1 | https://www.amazon.de/dp/B08TQSC5G9 | |
| Magnet | 1 | Magnet for connection between Controller and Base rig | https://www.amazon.de/dp/B0BKWQX36P |
| Windspeed Sensor | 1 | Windspeed sensor with impuls output and connection wiring | https://www.amazon.de/dp/B0C2F5MGKZ |
| Magnetic 3pin Pogo connector | 1 | Connection between Controller case and Base rig | https://www.amazon.de/dp/B0B1771YT4 |
| USB-C Port | 1 | USB-C Port for SW upload and as input for battery charge | https://www.amazon.de/dp/B0CZHDMFLZ |
| Ruthex M3S Brass Threads | 6 | M3 Short Brass inserts for meltin into the 3D Printed parts | https://www.amazon.de/dp/B09ZHSGHXD |
| M3x10 Flathead screw | 4 | Threads for clamp | |
| M3x6 countersunk screw | 2 | Threads for securing the magnet and the metal plate | |
| Alloy tube 30mm diameter | 2m | Base rig, 2x 1m length | |
| Base socket for Alloy tube | 1 | 3D printed part | Base socket |
| Windsensor socket | 1 | 3D printed part | Windsensor socket |
| Controller case | 1 | 3D printed part | Controller case |
| Base plate for controller case | 1 | 3D printed part | Base plate |
| Clamp | 1 | 3D printed part | Clamp |
| Tube connector | 1 | 3D printed part | Tube connector |
You can find the assembly instructions on the following link Assembly Instructions
The software is based on the Arduino framework and is build, using the PlatformIO develompent environment. You have two options to get the Software on the controller. You can build the Software by your own or you can use the provided binaries in the Release section and use an online flash tool. Both options are described in the next sections.
You can build the software by your own in opening the project in PlatformIO and choose the option Upload. After the build process, the binaries will be flashed on the connected device. In a second step, you have to use the option Build Filesystem Image. This step will generate a bin file which contains the html and image files which are needed for the web interface. In a last step, you have to use the option Upload Filesystem Image. This will flash the filesystem image on your controller.
If you want to use the precompiled binaries out of the Release section, you can open the following flash tool: https://espressif.github.io/esptool-js/ It is important, that you use the tool in a Chrome based browser.
After opening the webpage, you have to change the baudrate to the value 460800 and press the Connect Button.
The next step is to erase the flash on the controller. After doing this, enter the Flash Address 0x0and select the firmware-merged.binfile out of the release assets. Then press the Program button and wait until the flash process is finished.
In the final step, the filesystem has to be flashed on the controller. For this task you have to enter the Flash Address 0x00c90000 and select the littlefs.bin file out of the release assets. Then press the Program button. Now you are done and the controller is ready to go.
- BLE connection
FAI Sporting code rc modeling soaring https://www.fai.org/sites/default/files/sc4_vol_f3_soaring_25.pdf
| Category | Lower Windspeed threshold [m/s] | Upper Windspeed threshold [m/s] | Window duration [s] | Number of windows exceeded |
|---|---|---|---|---|
| Gerneral | 0 | 12 | 60 | 1 |
| F3K | 0 | 8 | 20 | 3 |
| F3B | 0 | 12 | 20 | 3 |
| F3G | 0 | 12 | 20 | 3 |
| F3J | 0 | 12 | 20 | 3 |
| F3L | 0 | 8 | 60 | 1 |
| F3F | 3 | 25 | 20 | 1 |
| F1x | 0 | 9 | 20 | 1 |
| F2x | 0 | 9 | 30 | 1 |
| F3C/F3N | 0 | 8 | 20 | 1 |
Extracts of the sporting codes of different FAI competition categories
C.17.2 Interruption a) The contest should be interrupted or the start delayed by the contest director in the following circumstances and in other exceptional circumstances decided by the contest director: i) Unless specified otherwise in the rules for a category or a particular class, the wind is continuously stronger than 12 m/s measured at two (2) metres above the ground at the starting line (flight line), for at least one minute
F3B.1.11. Weather Conditions / Interruptions a) The maximum wind speed for F3B contests is twelve (12) m/sec. The > contest has to be interrupted or the start delayed by the contest director if the wind speed exceeds > twelve (12) m/sec measured three (3) times for at least twenty (20) seconds in a time interval of five (5) > minutes two (2) metres above the ground at the start and landing area.
F3F.1.17. Weather Conditions and interruptions A round in progress must be interrupted if:- The wind speed is below three (3) m/sec or more than twenty-five (25) m/> sec for at least twenty (20) a) seconds. b) The direction of the wind deviates more than 45º from a line > perpendicular to the main direction of the speed course for at least twenty (20) seconds. The wind speed and wind direction are measured with the equipment of the > organiser at a representative position and height chosen from the experience of the organiser.
F3G.1.12. Weather Conditions/Interruptions a) The maximum wind speed for F3G contests is twelve (12) m/sec. The > contest has to be interrupted or the start delayed by the contest director if the wind speed exceeds > twelve (12) m/sec measured three (3) times for at least twenty (20) seconds in a time interval of five (5) > minutes two (2) metres above the ground at the start and landing area.
F3J.12. WEATHER CONDITIONS AND INTERRUPTIONS The maximum wind speed for F3J contests is twelve (12) m/sec two (2) m > above the ground at the centre of the launch corridor. The start of the contest must be delayed or the > contest has to be interrupted by the contest director if the wind speed exceeds twelve (12) m/sec measured > three (3) times for at least twenty (20) sec in a time interval of five (5) minutes at the start and landing > area.
F3K.5. WEATHER CONDITIONS / INTERRUPTIONS The maximum wind speed for F3K contests is eight (8) m/sec. The start of > the contest must be delayed or the contest has to be interrupted by the contest director if the wind > speed exceeds eight (8) m/sec measured three (3) times for at least twenty (20) sec in a time interval of five > (5) minutes at two (2) metres above the ground at the start and landing field. In the case of rain, the contest > director can interrupt the contest. When the rain stops, the contest starts again with the group that was flying, > which receives a re-flight.
F3L.6 Interruptions a) The Contest Director has the right to interrupt the competition and > relocate the starting line when the wind direction deviates too much or becomes a tailwind. b) The competition shall be interrupted by the Contest Director if the > wind is continuously stronger than eight (8) m/s measured at two (2) metres above the ground > at the starting line (flight line), for at least one minute.
INTERRUPTION OF A COMPETITION If the wind component perpendicular to the flight line exceeds 8ms/s for > a minimum of 20 seconds during a flight, the competition must be interrupted. The flight will be > repeated and the competition continued as soon as the wind subsides below the criterion. If the wind > does not subside before the round is completed, the entire round will be dropped. The determination > will be made by the organiser with concurrence of the FAI Jury.
F1.5 INTERRUPTION OF A CONTEST F1.5.1 Wind speed The interruption of contests is defined in CIAM General Rules C.17.2. > For Free Flight contests the contest should be interrupted when the wind measured at 2 metres above > the ground at the starting line is stronger than 9 m/s for at least 20 seconds.
4.0.1 INTERRUPTION OF THE CONTEST Wind stronger than 9 m/s for at least 30 seconds (instead of 12 m/s for > at least one minute in CIAM General Rules).