GA/TAS Conspicuity Device

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[!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.

| <br>Additional traffic via gatasServer | <br> soaring planes directly via FLARM | |--------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------| | Showing range of 24Km | <br> Two Tranceiver Version I have been flying with | | <br> GA/TAS Server selecting Aircraft | <br> All modules | | <br> GATAS Pulse Build Instructions | <br/> 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 | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | | ADS-L | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | | FLARM (2024) | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | | FANET | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | | ADS-B with Module. | :no_entry: | :heavy_check_mark: | :heavy_minus_sign: | | ADS-B via gatasConnect | :no_entry: | :heavy_check_mark: | :heavy_minus_sign: | | PAW | :construction: | :construction: | :construction: |

* 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 | :heavy_check_mark: | N/A | N/A | N/A | N/A | | AirConnect | N/A | N/A | :heavy_check_mark: | :heavy_check_mark: | N/A | | Dump1090 | N/A | N/A | N/A | N/A | :heavy_check_mark: | | gatasConnect | :heavy_check_mark: | :heavy_check_mark: | N/A | N/A | :heavy_check_mark: |

* 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 | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | Tested Frequently during flight | | EasyVFR 4 | :heavy_check_mark: | | | | | ForeFlight | :heavy_check_mark: | | | With part of ForeFLight extended spec and auto discovery | | XTrack | | :heavy_check_mark: | | Tested for connectivity | | Air navigation | :heavy_check_mark: | | | Tested for connectivity | | SeeYou Navigator | | :heavy_check_mark: | | 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