Configuration Parameters Reference¶

Complete reference of all OnSpeed configuration parameters. Configuration is stored as XML (config.cfg). The Default column shows the values set by FOSConfig::LoadDefaultConfiguration() in Config.cpp — what a fresh install or "Load Defaults" button press produces.

General Settings¶

XML Tag	Type	Default	Description
`AOA_SMOOTHING`	int	20	EMA filter window for AOA (samples)
`PRESSURE_SMOOTHING`	int	15	EMA filter window for pressure sensors (samples)
`DATASOURCE`	string	`SENSORS`	Data source: `SENSORS`, `TESTPOT`, `RANGESWEEP`, `REPLAYLOGFILE`
`REPLAYLOGFILENAME`	string	(empty)	Log file to replay when DATASOURCE=REPLAYLOGFILE
`SDLOGGING`	bool	false	Enable SD card data logging
`LOGRATE`	int	50	Logging rate in Hz: 50 (pressure rate) or 208 (IMU rate)
`CALWIZ_SOURCE`	string	`ONSPEED`	Calibration wizard IAS source: `ONSPEED` or `EFIS`
`AHRS_ALGORITHM`	int	0	AHRS algorithm: 0=Madgwick, 1=EKF6. See Advanced Settings before changing.

EFIS Settings¶

XML Tag	Type	Default	Description
`EFISTYPE`	string	`VN-300`	EFIS type: `VN-300`, `ADVANCED`, `DYNOND10`, `GARMING5`, `GARMING3X`, `MGL`
`SERIALEFISDATA`	bool	false	Enable reading EFIS serial data
`SERIALOUTFORMAT`	string	`ONSPEED`	Display serial output: `ONSPEED` or `G3X`

Orientation¶

XML Path	Type	Default	Options
`ORIENTATION > PORTS`	string	`FORWARD`	`FORWARD`, `AFT`, `UP`, `DOWN`, `LEFT`, `RIGHT`
`ORIENTATION > BOX_TOP`	string	`UP`	`UP`, `DOWN`, `LEFT`, `RIGHT`

Volume & Audio¶

XML Path	Type	Default	Description
`VOLUME > ENABLED`	bool	false	Use hardware volume potentiometer
`VOLUME > HIGH_ANALOG`	int	4095	ADC value at max volume
`VOLUME > LOW_ANALOG`	int	0	ADC value at min volume
`VOLUME > DEFAULT`	int	100	Default volume (0–100%) when pot disabled
`VOLUME > ENABLE_3DAUDIO`	bool	false	Enable stereo lateral-G panning
`VOLUME > MUTE_UNDER_IAS`	int	30	Mute audio below this IAS (knots); 0 = always on
`OVERGWARNING`	bool	false	Enable G-limit warning tone

Vno Chime¶

XML Path	Type	Default	Description
`VNO > SPEED`	int	150	Vno speed threshold (knots)
`VNO > CHIME_INTERVAL`	int	3	Chime repeat interval (seconds)
`VNO > CHIME_ENABLED`	bool	false	Enable Vno overspeed chime

Load Limits¶

Over-G warning thresholds (fire when OVERGWARNING is enabled). Distinct from the airframe structural G-limit in AIRCRAFT > G_LIMIT, which drives the maneuvering-speed computation.

XML Path	Type	Default	Description
`LOAD_LIMIT > POSITIVE`	float	4.0	Positive-G warning threshold
`LOAD_LIMIT > NEGATIVE`	float	-2.0	Negative-G warning threshold
`LOAD_LIMIT > ASYMMETRIC_GYRO_LIMIT`	float	15.0	Roll/yaw rate (deg/s) above which reduced G-limits apply
`LOAD_LIMIT > ASYMMETRIC_REDUCTION`	float	0.667	G-limit multiplier during asymmetric flight (e.g., 0.667 = ⅔)

Sensor Biases¶

XML Path	Type	Default	Description
`BIAS > PFWD`	int	8192	Pitot pressure 14-bit count zero bias
`BIAS > P45`	int	8192	AOA pressure 14-bit count zero bias
`BIAS > PSTATIC`	float	0.0	Static pressure offset (millibars; subtracted from measured mbar)
`BIAS > GX`	float	0.0	Forward acceleration bias (G)
`BIAS > GY`	float	0.0	Lateral acceleration bias (G)
`BIAS > GZ`	float	0.0	Vertical acceleration bias (G)
`BIAS > PITCH`	float	0.0	Pitch angle bias (degrees)
`BIAS > ROLL`	float	0.0	Roll angle bias (degrees)

CAS Curve (Airspeed Calibration)¶

XML Path	Type	Default	Description
`CAS_CURVE > TYPE`	int	1	Curve type: 1=polynomial
`CAS_CURVE > X3`	float	0.0	Cubic coefficient
`CAS_CURVE > X2`	float	0.0	Quadratic coefficient
`CAS_CURVE > X1`	float	1.0	Linear coefficient (1.0 = pass-through)
`CAS_CURVE > X0`	float	0.0	Constant coefficient
`CAS_CURVE > ENABLED`	bool	false	Apply CAS correction

Optional Features¶

XML Tag	Type	Default	Description
`BOOM`	bool	false	Enable boom probe serial input
`BOOMCHECKSUM`	bool	true	Validate boom data checksums
`BOOMCONVERTDATA`	bool	false	Apply polynomial calibration curves to boom data (false = log raw counts)
`OATSENSOR`	bool	false	Enable DS18B20 OAT sensor

Aircraft Parameters¶

XML Path	Type	Default	Description
`AIRCRAFT > GROSS_WEIGHT`	int	0	Max gross weight (lbs)
`AIRCRAFT > BEST_GLIDE_IAS`	float	0.0	Best glide speed at max gross weight (knots)
`AIRCRAFT > VFE`	float	0.0	Max flaps-extended speed (knots)
`AIRCRAFT > G_LIMIT`	float	0.0	Airframe structural load factor limit. Used for maneuvering-speed computation. The config page offers FAR 23 category radio buttons (Normal +3.8G, Utility +4.4G, Aerobatic +6.0G) plus a Custom field.

Per-Flap Position Settings¶

Each FLAP_POSITION element contains:

XML Path	Type	Description
`DEGREES`	int	Flap deflection angle
`POT_VALUE`	int	ADC reading for this position
`LDMAXAOA`	float	Best L/D angle of attack (degrees)
`ONSPEEDFASTAOA`	float	Fast approach AOA (degrees)
`ONSPEEDSLOWAOA`	float	Slow approach AOA (degrees)
`STALLWARNAOA`	float	Stall warning threshold AOA (degrees)
`STALLAOA`	float	Actual stall AOA from calibration (degrees)
`MANAOA`	float	Maneuvering speed AOA (degrees)
`ALPHA0`	float	Zero-lift angle from physics fit (degrees). Typically negative — wing incidence puts the fuselage nose-down at zero wing lift.
`ALPHASTALL`	float	Stall angle from physics fit (degrees)
`KFIT`	float	Lift sensitivity from IAS-to-AOA fit (deg·kt²)

The firmware validates setpoint ordering on save and on load. The required ordering for each flap position is ALPHA0 < LDMAXAOA < ONSPEEDFASTAOA < ONSPEEDSLOWAOA < STALLWARNAOA < STALLAOA. A violation surfaces on the config page as a per-flap SetpointOrderError (e.g., Alpha0 (3.5) must be less than LDMAX (1.5) when α₀ has been entered with the wrong sign). STALLAOA and ALPHA0 skip the check at exactly 0.0, which is the uncalibrated sentinel.

Per-Flap AOA Curve¶

XML Path	Type	Description
`AOA_CURVE > TYPE`	int	1=polynomial, 2=logarithmic, 3=exponential
`AOA_CURVE > X3`	float	Cubic coefficient
`AOA_CURVE > X2`	float	Quadratic coefficient
`AOA_CURVE > X1`	float	Linear coefficient
`AOA_CURVE > X0`	float	Constant coefficient