FIX-Gateway

Status: Open Source — Experimental Amateur-Built Category
License: GPL v2
Language: Python 3
Snap: fixgateway on snapcraft.io

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What This Is

FIX-Gateway is the central avionics data broker for the MakerPlane and MAOS avionics ecosystem. It is a Python daemon that maintains a real-time database of named flight parameters and routes data between heterogeneous sources and consumers via a plugin architecture.

Think of it as an avionics middleware bus: any sensor, protocol, or simulator can publish data to one standard parameter namespace, and any display or system can subscribe without knowing where the data came from.

Architecture

[CAN-FIX bus] ─────────────────────────────────┐
[GPS / gpsd] ───────────────────────────────────┤
[Stratux ADS-B] ────────────────────────────────┤
[MAVLink autopilot / MAOS-FCS] ─────────────────┤
[X-Plane / FlightGear simulator] ───────────────┤→ [FIX-Gateway database] ─→ [pyEfis EFIS display]
[RPi IMU (BNO055)] ─────────────────────────────┤                          ─→ [pyAvMap moving map]
[RPi barometer (BMP085)] ───────────────────────┤                          ─→ [NetFIX network clients]
[MGL / Dynon / GrandRapids EGS serial] ─────────┤                          ─→ [CAN-FIX output nodes]
[Compute plugin (derived values)] ──────────────┘

Parameter Database

The central database maps named keys to typed, bounded, toleranced values. Key domains include:

Domain	Example Keys
Navigation	LAT, LONG, ALT, IAS, TAS, GS, HEAD, TRACK, XTE
AHRS	PITCH, ROLL, YAW, ALAT, ALONG, ANORM
Engine	RPM1, MAP1, EGT11–EGT16, CHT11–CHT16, OILP1, OILT1, FFLOW1
Control surfaces	CTLPTCH, CTLROLL, CTLYAW, CTLFLAP, CTLATP, CTLCOLL
Electrical	VOLT1, CURR1, ALT1
COM/NAV radios	COM1ACT, COM1SBY, NAV1ACT, NAV1SBY
Trims	PITCHTRIM, ROLLTRIM, YAWTRIM
Autopilot	APENG, APALT, APHDG, APSPD

Each key has defined type, min/max bounds, units, and a tolerance (stale data) timer — if a key is not updated within its tol window it is marked stale, which pyEfis can display as a failure flag.

Plugin Ecosystem

Input/output plugins currently available:

Plugin	Description
canfix	CAN-FIX bus via SocketCAN or MCP2515
gpsd	GPS position and ground track from gpsd
stratux	ADS-B traffic and GPS from Stratux receiver
mavlink	MAVLink autopilot/FCS data (compatible with MAOS-FCS)
netfix	TCP/IP network interface for distributed avionics
xplane	X-Plane 11/12 flight simulator
fgfs	FlightGear flight simulator
dynon	Dynon serial protocol
mgl / mgl_serial	MGL Avionics serial protocol
grand_rapids_eis	Grand Rapids Technologies EIS serial
megasquirt	MegaSquirt ECU data
rpi_bno055	Raspberry Pi IMU (attitude)
rpi_bmp085	Raspberry Pi barometric sensor
rpi_mcp3008	Raspberry Pi 8-channel SPI ADC
rpi_rotary_encoder	Rotary encoder inputs (altimeter, heading bugs)
rpi_button	GPIO button inputs
compute	Derived value computation (e.g., density altitude, TAS from IAS/OAT/ALT)
data_recorder	Log all parameters to file
data_playback	Replay recorded flight data
quorum	Multi-source data arbitration / voting
annunciate	Generate warning/caution/advisory annunciations from parameter limits
demo	Simulated flight data for display testing

Installation

git clone https://github.com/makerplane/FIX-Gateway.git fixgw
cd fixgw
make venv
source venv/bin/activate
make init

Run the server:

./fixGw.py

Run the debug client:

./fixGwClient.py        # console
./fixGwClient.py --gui  # GUI client

Run tests:

make test

Cleanup to remove the virtual environment and test output:

make clean

Configuration

Configuration files live in src/fixgw/config/:

• default.yaml — main server config; selects which plugins load
• database.yaml — parameter namespace definition
• database/custom.yaml — add or override parameters without touching upstream files
• init_data/custom.ini — set initial parameter values for your specific aircraft

Important Disclaimer

FIX-Gateway is developed for Experimental Amateur-Built aircraft use only.
It is not FAA-approved avionics software. Aircraft builders are responsible for all integration and safety decisions.