GA/TAS Conspicuity Device

Tip

Please visit the GA/TAS WIKI for build information.

The GA/TAS Conspicuity device is designed for General Aviation pilots flying in areas where multiple protocols, such as OGN, Flarm, ADS-L and FANET, are used. It can transmit and receive multiple protocols simultaneously (excluding sending ADS-B) using one or more transceiver modules. All received traffic is sent to your Electronic Flight Bag (EFB), such as SkyDemon, via the GDL90 protocol via WIFI or NMEA via bluetooth or WIFI.

The device is built around the Raspberry RP2040/RP2350 and can be configured with a custom PCB that supports either two transceivers or a simpler configuration with one with modules from Waveshare which makes it more of a plug-and-play. In both setups, it can send and receive all protocols using time-sharing technology. The device can store configurations for multiple aircraft, which can be selected through an easy-to-use web interface or via gatasServer

Powered by a Li-Ion battery, the device includes a PCB with a USB-C charger. The estimated battery life is between 6 and 10 hours, though this is subject to further testing.

For FLARM it's current range has been t ested up to 24Km (see below screenshots) but on average a good 15Km can be expected. This will give you plenty of time to avoid the traffic. EFBs like SkyDemon can also send out audible traffic warnings.

Note: Although it's primary design is based around GA traffic, there is nothing in the hardware to prevent other use cases like gliders, paragliders and hang gliders. The goal of the project is to be seen by transmitting different protocols and be able to see them.

Additional traffic via gatasServer	soaring planes directly via FLARM
Showing range of 24Km	Two Tranceiver Version I have been flying with
GA/TAS Server selecting Aircraft	All modules
GATAS Pulse Build Instructions	GATAS Pulse

Note

The screenshot of SkyDemon was taken from the car while driving for safety reasons. The screenshot of the web interface showing the 24Km was taken while parked and the device placed on top of the car for better air-2-air visibility.

Radio Protocol Support

Radio Protocol is the method used to communicate with other conspicuity devices

Radio Protocol.	Send	Receive	Multi Protocol
OGN	✔️	✔️	✔️
ADS-L	✔️	✔️	✔️
FLARM (2024)	✔️	✔️	✔️
FANET	✔️	✔️	✔️
ADS-B with Module.	⛔	✔️	➖
ADS-B via gatasConnect	⛔	✔️	➖
PAW	🚧	🚧	🚧

* Multi Protocol is a feature of GA/TAS that allows to enable multiple protocols both send and receive on a single transceiver by sharing the air time. The Transceiver will alternate between the different protocols and prioritize a specific protocol when it receives data for that protocol.

• Fanet support sending and receving including forwaring of FANET messages
• gatasConnect is a protocol and service to receive additional traffic information via mobile connection.

Communication support

Communication support is what protocols are supported to other devices like electronic flight bags or other equipment.

Protocol	Send UDP over WIFI	Receive UDP over WIFI	Send Bluetooth	Send TCP over WIFI	Receiver over TCP WIFI
GDL90	✔️	N/A	N/A	N/A	N/A
AirConnect	N/A	N/A	✔️	✔️	N/A
Dump1090	N/A	N/A	N/A	N/A	✔️
gatasConnect	✔️	✔️	N/A	N/A	✔️

* Sending GDL90 over Bluetooth is not used in the industry so this is currently not setup. If this is really required, then this can be done. Do let me know the use case

Tested with Electronic Flight Bag

GA/TAS is currently tested with SkyDemon only, If you made it work with any other software on Phone or Tablet, do let me know so I can add or help out to make this work.

EFB	GDL90 over WIFI	Bluetooth	DataPort (NMEA) WIFI	Note
SkyDemon	✔️	✔️	✔️	Tested Frequently during flight
EasyVFR 4	✔️
ForeFlight	✔️			With part of ForeFLight extended spec and auto discovery
XTrack		✔️		Tested for connectivity
Air navigation	✔️			Tested for connectivity
SeeYou Navigator		✔️		GPS and traffic targets shown

[!INFO] Thanks to PocketFMS (EasyVFR) for providing a Developer license of EasyVFR 4 to help test GA/TAS GDL90

gatasConnect & gatasServer

gatasConnect and gatasServer provide a lightweight UDP-based protocol for receiving additional traffic information. This is still somewhat experimental but up an running and usable, it's free for you to use on the pre-configured server. Just enable 'gatasConnect' and ensure GA/TAS does have internet access via your mobile dev ice. Configure Client mode to connect to your mobile's access point, how cool is that!

Tip

gatasConnect uses https://airplanes.live to to deliver internet-based traffic to your GA/TAS and into your EFB, including ADS-B Out and MLAT-derived traffic. If you have the chance, please consider adding airplanes.live to your existing feed or creating a new one. By doing so, you help improve traffic coverage for yourself and for others and contribute to safer flying.

Features

• Online web application to select your configured aircraft
• Eliminates the need to manually connect to GA/TAS vi WIFI to choose an aircraft, saves time and you can focus on flying.
• Still compatible with GA/TAS aircraft selection via gatas build in web service
• Future support for automatic aircraft selection based on correlated ADS-B traffic

Network Usage

• Transmit: ~52 bytes/second
• Receive: ~1024 bytes/second at 30 aircraft. (supports up to 30 nearby aircraft)

External Libraries and frameworks used

Most libraries are used 'as-is' Some of them have been slightly modified for performance reasons, compatibility or other reasons.

1. Raspberry PI PICO SDK https://github.com/raspberrypi/pico-sdk
2. FreeRTOS, GA/TAS uses tasks and timers and avoids loops and runs in multi-core SMP mode. https://www.freertos.org
3. LWiP Pretty cool and sometimes confusing TCP/IP protocol suite https://savannah.nongnu.org/projects/lwip/
4. ArduinoJSON for loading and storing configuration https://arduinojson.org
5. etlcpp pretty awesome library written by John Wellbelove https://www.etlcpp.com
6. libcrc https://github.com/lammertb/libcrc
7. minmea for parsing NMEA sentences https://github.com/kosma/minmea/
8. Catch2 for unit testing https://github.com/catchorg/Catch2
9. Easy to use FANET implementation in C++ https://github.com/rvt/FANET

GA/TAS Disclaimer

[!IMPORTANT] > Important Notice: Use at Your Own Risk

The GA/TAS Conspicuity Device is provided "as is," without any guarantees or warranties of any kind. By using this device, you acknowledge and agree that:

1. No Warranty: The creators of GA/TAS make no claims or guarantees regarding the accuracy, reliability, or fitness for a specific purpose of the device or its associated software. This includes, but is not limited to, communication with OGN, Flarm, ADS-L, or any other protocols.
2. Assumption of Risk: You assume full responsibility for any and all risks associated with the use of GA/TAS. This includes, but is not limited to, risks related to hardware malfunctions, software issues, or incorrect transmission/interpretation of data.
3. Limitation of Liability: Under no circumstances shall the creators, contributors, or affiliates of GA/TAS be held liable for any direct, indirect, incidental, or consequential damages resulting from the use, misuse, or inability to use the device or its software.
4. General Aviation Use: GA/TAS is intended for use in General Aviation environments where multiple protocols such as OGN, Flarm, and ADS-L are used. It is not certified for professional or commercial aviation use and should not be relied upon as the sole source of traffic or navigation information.
5. Compliance: Users are responsible for ensuring that the use of GA/TAS complies with local aviation regulations and requirements. It is your responsibility to ensure that the device operates within the legal limits and safety standards for your jurisdiction.
6. IFR Use: GA/TAS is not intended for usage during an IFR flight.

By using GA/TAS, you agree to the terms of this disclaimer and acknowledge that you are using the device and its software at your own risk.