Parameters

Written by Max GardenswartzUpdated 2026-11-10Autonomy Park

At a glance

Every PX4 parameter the Homebrew template sets, what it is set to, and why. Use it with the PX4 v1.16 reference only.

Read Parameters in the PX4 v1.16 Reference Only

To understand any parameter on this page, use the PX4 v1.16 parameter reference. Do not use the main (latest) reference: parameters differ between PX4 versions.

The Taranis QX7 Is Max Gardenswartz's Personal Radio

The Taranis QX7 belongs to Max Gardenswartz personally, not to the lab, and he will not leave it with the lab when he graduates in 2028. He set it up for test flights because it was familiar and convenient. Research funds can only buy equipment that is on the Blue list, so the lab needs a better long-term plan: see Radio and RC Setup.

The Homebrews' SD cards are slow: see Known Issues.

Warning

Before you take off the Homebrew, make sure the following settings are correct.

Reference: PX4 v1.16 parameter definitions (release/1.16; entries added later were checked against the v1.16.2 tag). "Default" means the v1.16 metadata default plus the CubePilot Cube Orange board defaults (rc.board_defaults), the multicopter defaults in rc.mc_defaults (which overrides RTL_RETURN_ALT and RTL_DESCEND_ALT and sets MAV_TYPE), and the Generic Quadcopter airframe defaults (4001_quad_x, which sets the CA_ROTOR* positions).

Legend: ✅ = matches the multicopter default, ❌ = differs from the multicopter default.

The Relevance column in every table tells you which descriptions are most important to read: High means read the Reason before you change or rely on the parameter, and "-" means it is rarely worth your time.

BAT: Battery

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
BAT1_CAPACITY	-1	Disabled	✅	-	Default −1 (unknown). Left disabled so remaining charge is estimated from voltage only. The current sensor is not working, so coulomb counting would integrate invalid current. Set to 16000 mAh (all Homebrew batteries) once current sensing is verified.
BAT1_I_OVERWRITE	0 A	Idle-current overwrite disabled	✅	-	Default 0 (disabled, the measured current is used).
BAT1_N_CELLS	6	6S battery	❌	-	Default 0 (unknown). Should be set by the user to match the battery.
BAT1_R_INTERNAL	−1 Ω	Use the online estimate	✅	-	Default −1 (use the online estimate). Left at default because the current sensor is not working, and both the sag compensation and the online estimate need valid current. The PX4 parameter description says this is per cell.
BAT1_SOURCE	0	Battery 1 read from the power module	✅	-	Default 0 (Power Module). The other options are 1 (External, from MAVLink battery status messages) and 2 (ESCs, taken from the esc_status message, which per the v1.16.2 description requires the ESCs to report both voltage and current). PX4 currently cannot read the current from the PDB. Max thinks setting this to 2 might fix that, but this is not verified, and since the notes for COM_ARM_CHK_ESCS say these ESCs do not support telemetry, it may not be possible at all. Requires reboot.
BAT1_V_CHARGED	4.05 V	4.05 V per cell when full	✅	High	Default 4.05 V. The PX4 LiPo default, defined as the per-cell voltage under load rather than the resting full-charge voltage.
BAT1_V_EMPTY	3.6 V	3.6 V per cell when empty	✅	-	Default 3.6 V. The PX4 LiPo default, defined as the per-cell voltage under load when the pack is effectively empty.
BAT2_A_PER_V	17	Battery 2 current scale at board default	✅	-	Default 17 (Cube Orange board default). Leave at default since there is no BAT2.
BAT2_CAPACITY	−1 mAh	Battery 2 capacity unknown	✅	-	Default −1. Leave at default since there is no BAT2.
BAT2_I_CHANNEL	−1	Battery 2 current ADC channel at board default	✅	-	Default −1 (board default). Leave at default since there is no BAT2.
BAT2_I_OVERWRITE	0 A	Idle-current overwrite disabled	✅	-	Default 0. Leave at default since there is no BAT2.
BAT2_N_CELLS	0	Cell count unknown	✅	-	Default 0. Leave at default since there is no BAT2.
BAT2_R_INTERNAL	−1 Ω	Use the online estimate	✅	-	Default −1. Leave at default since there is no BAT2.
BAT2_SOURCE	−1	Battery 2 disabled	✅	-	Default −1 (Disabled). Leave at default since there is no BAT2.
BAT2_V_CHANNEL	−1	Battery 2 voltage ADC channel at board default	✅	-	Default −1 (board default). Leave at default since there is no BAT2.
BAT2_V_CHARGED	4.05 V	4.05 V per cell when full	✅	-	Default 4.05 V. Leave at default since there is no BAT2.
BAT2_V_DIV	10.1	Battery 2 voltage divider at board default	✅	-	Default 10.1 (Cube Orange board default). Leave at default since there is no BAT2.
BAT2_V_EMPTY	3.6 V	3.6 V per cell when empty	✅	-	Default 3.6 V. Leave at default since there is no BAT2.
BAT3_CAPACITY	−1 mAh	Battery 3 capacity unknown	✅	-	Default −1. Leave at default since there is no BAT3.
BAT3_N_CELLS	0	Cell count unknown	✅	-	Default 0. Leave at default since there is no BAT3.
BAT3_R_INTERNAL	−1 Ω	Use the online estimate	✅	-	Default −1. Leave at default since there is no BAT3.
BAT3_SOURCE	−1	Battery 3 disabled	✅	-	Default −1 (Disabled). Leave at default since there is no BAT3.
BAT3_V_CHARGED	4.05 V	4.05 V per cell when full	✅	-	Default 4.05 V. Leave at default since there is no BAT3.
BAT3_V_EMPTY	3.6 V	3.6 V per cell when empty	✅	-	Default 3.6 V. Leave at default since there is no BAT3.
BAT_AVRG_CURRENT	15 A	15 A expected in-flight current	✅	-	Default 15 A. Only used to initialize the in-flight average-current estimate, which feeds remaining-flight-time and RTL triggering.
BAT_CRIT_THR	0.25	Critical at 25% remaining	❌	High	Default 0.07. Triggers the critical-battery reaction (land) much earlier, so the Homebrew lands with a healthy reserve (about 3.71 V per cell with the linear 3.6–4.05 V mapping). Must stay below BAT_LOW_THR and above BAT_EMERGEN_THR. Units are normalized 0–1, not percent.
BAT_EMERGEN_THR	0.15	Emergency at 15% remaining	❌	High	Default 0.05. Immediate-landing level (about 3.67 V per cell). Must stay below BAT_CRIT_THR.
BAT_LOW_THR	0.35	Low at 35% remaining	❌	High	Default 0.15. First warning level (about 3.76 V per cell). Must stay above BAT_CRIT_THR.

Note that BAT1_V_DIV and BAT1_A_PER_V are calibrated separately for every quadcopter!

In v1.16.2 only batteries 1 and 2 have BAT*_V_DIV, BAT*_A_PER_V, BAT*_V_CHANNEL, BAT*_I_CHANNEL and BAT*_I_OVERWRITE, so those parameters do not exist for battery 3; only the six BAT3_* parameters above do.

CA: Control Allocator

Positions are along the body X and Y axes, in metres, relative to the center of gravity. They describe the physical span of the airframe and are critical to the motor mixer and flight stability. The Generic Quadcopter airframe (4001_quad_x) sets them to ±1 m. The metadata default is 0.

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
CA_ROTOR0_PX	0.25 m	Rotor 0 at +0.25 m on X	❌	-	Default 1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR0_PY	0.25 m	Rotor 0 at +0.25 m on Y	❌	-	Default 1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR1_PX	−0.25 m	Rotor 1 at −0.25 m on X	❌	-	Default −1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR1_PY	−0.25 m	Rotor 1 at −0.25 m on Y	❌	-	Default −1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR2_PX	0.25 m	Rotor 2 at +0.25 m on X	❌	-	Default 1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR2_PY	−0.25 m	Rotor 2 at −0.25 m on Y	❌	-	Default −1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR3_PX	−0.25 m	Rotor 3 at −0.25 m on X	❌	-	Default −1 m (airframe 4001). Physical span of the airframe.
CA_ROTOR3_PY	0.25 m	Rotor 3 at +0.25 m on Y	❌	-	Default 1 m (airframe 4001). Physical span of the airframe.

COM: Commander

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
COM_ACT_FAIL_ACT	0	Warning only on actuator failure	✅	-	Default 0 (warning only). The action taken when the failure detector reports a failed actuator (motor); the other options are 1 Hold, 2 Land, 3 Return, and 4 Terminate. It only matters if the actuator failure check is enabled and configured through the FD_ACT_* parameters (see the FD section). Max is unsure whether this should be changed to Land (2) since the current sensor is not working, but he uses 0 and it has been fine.
COM_ARM_AUTH_MET	0	One-step arming	✅	-	Default 0 (one arm: request authorization and arm as soon as it is received). The alternative is 1 (two-step arm: the first arm command requests authorization and the second arms if it is authorized). It is only used when COM_ARM_AUTH_REQ is on, so it has no effect here.
COM_ARM_AUTH_REQ	0	No arm authorization required	✅	-	Default 0 (disabled). No authorization is required to arm other than the arm switch.
COM_ARM_BAT_MIN	0.50	Refuse to arm below 50% battery	❌	High	Default −1 (uses BAT_CRIT_THR). Prevents permanently damaging the battery through negligence.
COM_ARM_CHK_ESCS	0	ESC arming checks disabled	✅	-	Default 0 (disabled). Enables checks of the ESCs' online status and failures. It is specific to ESCs that report telemetry and must only be enabled if the ESCs support it; these ESCs do not.
COM_ARM_HFLT_CHK	0	Disabled; allow arming even if hardfault files are on the SD card	❌	High	Default 1 (enabled). The CubePilot Orange+ (a flight controller similar to our CubePilot Blue) has a bug in PX4 1.16.2, PX4 issue #29346: disconnecting from USB causes a hard fault, leaving a log that prevents arming. That is easy to do by accident and is not a problem, so it should not prevent arming. Enabling the check means the failed USB connection prevents all further arming until you delete the logs from SD (via the NuttX terminal or taking the SD card out). Leave it off until the bug is patched (likely PX4 1.19).
COM_ARM_MAG_STR	1	Deny arming on a magnetic disturbance	❌	-	Default 2 (warning only). Controls what happens when the estimator detects a strong magnetic disturbance, as checked according to EKF2_MAG_CHECK: 0 disabled, 1 deny arming, 2 warning only. Denying arming, not just warning, keeps a vehicle with a disturbed magnetometer on the ground.
COM_ARM_SDCARD	2	No SD prevents arming	❌	-	Default 1 (warning only). No SD card detected despite on in the quad (which should be the case) means the FC might damage, so this is reasonable proxy. SD card might also have burnt out from too many read-writes. This is natural and can happen with time.
COM_ARM_WO_GPS	0	Deny arming when the GPS checks fail	❌	High	Default 1 (warning only). For an autonomous quadcopter, having no usable GPS should stop it from moving forward. These drones only ever fly outdoors. In the v1.16 source, 0 denies arming when a check in EKF2_GPS_CHECK fails, and it also requires a global position estimate ("Global position estimate required"), which is why EKF2_HGT_REF must stay 1. With EKF2_GPS_CHECK = 1023 the default thresholds apply (EKF2_REQ_NSATS 6, EKF2_REQ_PDOP 2.5, EKF2_REQ_EPH 3 m, EKF2_REQ_EPV 5 m), so a poor fix (for example without RTK) can block arming.
COM_ARMABLE	1	Arming allowed	✅	-	Default 1 (arming allowed). Set it to 0 to prevent arming entirely, for example for safety or maintenance reasons, so the vehicle cannot be used by accident.
COM_DISARM_LAND	2.0 s	2.0 s of successful landing detected	✅	-	Default 2.0 s. PX4 must detect that the vehicle is on the ground for this long before disarming the motors at the end of Land mode procedure.
COM_DISARM_MAN	1	Manual disarm allowed in manual thrust modes	✅	-	Default 1 (enabled). Allows disarming with the switch, stick, or button during multicopter flight, but only in modes where the throttle stick directly controls thrust (for example Stabilized or Acro). With 0, disarming is not allowed unless the vehicle has landed. Disarming in flight kills the motors.
COM_DISARM_PRFLT	10 s	Disarm after 10 s without takeoff	✅	-	Default 10 s. If the vehicle is armed and has not taken off within this time, it disarms again (a negative value disables this). The user has 10 s to act after arming.
COM_DL_LOSS_T	5 s	GCS connection counted as lost after 5 s	❌	-	Default 10 s. Tighter is better, and 10 s is too generous, especially for an autonomous quadcopter. Because NAV_DLL_ACT is set as 0 later, this value is ignored, but it's good to have.
COM_FAIL_ACT_T	5 s	Wait 5 s in Hold before a failsafe action	✅	-	Default 5 s. Before a failsafe action (Return, Land, or Hold) is executed, PX4 first waits this long in Hold mode so the user can realize something is wrong. During that time the pilot cannot take over with the stick override (COM_RC_OVERRIDE), although switching modes is still allowed; afterwards the configured action runs and the stick override works again. A value of 0 removes the delay. From the description it applies to the failsafes that are active here, such as RC loss (NAV_RCL_ACT) and offboard loss (COM_OBL_RC_ACT); the GCS-loss failsafe is disabled (NAV_DLL_ACT = 0), so it never starts this wait (my reading of the description; not tested).
COM_FLT_TIME_MAX	−1 s	No maximum flight time	✅	-	Default −1 (disabled). When set, the vehicle aborts the current operation and returns to launch once the time since takeoff exceeds this value, with a warning every minute starting at 90 % of it. No maximum flight time is used; the battery thresholds limit the flight time instead.
COM_FLTMODE1	2	Slot 1: Position	❌	-	Default −1 (unassigned). Necessary for using the Taranis QX7 remote specifically. With RC_MAP_FLTMODE the mode is picked by the range channel 5 is in, across six slots. A different RC would need a different scheme.
COM_FLTMODE2	1	Slot 2: Altitude	❌	-	Default −1 (unassigned). Same Taranis QX7 scheme.
COM_FLTMODE3	4	Slot 3: Hold	❌	-	Default −1 (unassigned). Same Taranis QX7 scheme.
COM_FLTMODE4	1	Slot 4: Altitude	❌	-	Default −1 (unassigned). Same Taranis QX7 scheme. Slots 2 and 4 are both Altitude.
COM_FLTMODE5	11	Slot 5: Land	❌	-	Default −1 (unassigned). Same Taranis QX7 scheme.
COM_FLTMODE6	8	Slot 6: Stabilized	❌	-	Default −1 (unassigned). Same Taranis QX7 scheme.
COM_FLTT_LOW_ACT	3	Return when remaining flight time is low	✅	-	Default 3 (Return). The action taken when the estimated remaining flight time drops below the time needed to reach the RTL destination (0 None, 1 Warning, 3 Return). It should hardly ever matter since the Park is so small. What is critical is that the return heights stay below the net, which is covered by RTL_RETURN_ALT and RTL_DESCEND_ALT.
COM_HOME_EN	1	Home position set automatically	✅	-	Default 1 (enabled). PX4 sets the home position automatically when possible (per Max, on arm or boot). Requires reboot. Home cannot be reset without arming, which is one reason the geofence altitude limit is not used (see GF_MAX_VER_DIST).
COM_HOME_IN_AIR	0	Home is never set in the air	✅	-	Default 0 (disabled). If enabled, the autopilot may set its home position after takeoff (back-computed from the local position when one is available). Disabled so that home is never set while flying.
COM_IMB_PROP_ACT	0	Warning only on imbalanced propeller	✅	-	Default 0 (warning only). The action taken when the failure detector detects an imbalanced propeller (−1 disabled, 0 warning, 1 Return, 2 Land). The detection threshold is FD_IMB_PROP_THR (default 30; 0 disables the detection). No motivation to change.
COM_KILL_DISARM	0 s	Kill switch disarms immediately	❌	-	Default 5 s. Kill activates immediately with no timeout. Be careful!!!
COM_LOW_BAT_ACT	2	Land mode	❌	-	Default 0 (Warning only). Land instead of just warning at critical battery.
COM_OBC_LOSS_T	5 s	Companion computer loss warning after 5 s	✅	-	Default 5 s. Time without a connection to the onboard computer after which PX4 only issues a warning; it is not a failsafe. No motivation to change: the round-trip time over MAVROS and the age of the odometry matter much more, and those have to be checked by the offboard code, not by PX4.
COM_OBL_RC_ACT	4	Land mode (on offboard loss)	❌	-	Default 0 (Position mode). Note: this is the offboard-loss action, not RC loss (see NAV_RCL_ACT).
COM_OF_LOSS_T	0.5	0.5 s offboard-loss timeout	❌	-	Default 1.0 s. Lowering makes crashes less likely during offboard network dropouts since the failsafe triggers faster. Too low may make this sensitive to network lag, but lower than 0.5 should be tested for feasibility.
COM_POS_FS_EPH	5 m	Failsafe above 5 m horizontal position error	✅	-	Default 5 m (−1 disables). The horizontal position error (EPH) above which PX4 triggers a failsafe; once the error has been below the threshold, a factor of 2.5 is applied before the position is invalidated. Kept at default because the offboard code should land, or refuse to arm, whenever the GPS fix type is not 6 (RTK fixed), long before PX4's own failsafe matters.
COM_POS_LOW_ACT	5	Land on a low position accuracy	❌	-	Default 3 (Return). The action taken when the position accuracy is worse than the COM_POS_LOW_EPH threshold (0 None, 1 Warning, 2 Hold, 3 Return, 4 Terminate, 5 Land). Set to Land so that a poor position estimate lands the vehicle instead of returning it. Per the v1.16.2 description the action is only executed in Mission or Hold (loiter) modes, and otherwise it is only a warning; while COM_POS_LOW_EPH is disabled it has no effect at all.
COM_POS_LOW_EPH	−1 m	Low accuracy failsafe disabled	✅	-	Default −1 (disabled). Threshold for COM_POS_LOW_ACT. The local position must still be valid for it to apply, which requires some velocity aiding or a large dead-reckoning time (EKF2_NOAID_TOUT), together with a high COM_POS_FS_EPH. No motivation to change.
COM_POSCTL_NAVL	1	Land when navigation is lost in Position mode	❌	High	Default 0 (Altitude mode). The flight mode used when the navigation accuracy is no longer adequate for position control in manual Position mode: 0 Altitude mode, 1 Land mode (descend). This should never happen with RTK, but if the GPS is bad the vehicle lands.
COM_PREARM_MODE	0	Prearm state disabled	✅	-	Default 0 (disabled). The prearmed state is an intermediate state between disarmed and armed in which non-throttling actuators are active; the options are 0 disabled, 1 safety button, 2 always. The prearm feature is not used here.
COM_RC_IN_MODE	3	RC or Joystick, keep first	✅	-	Default is 3 in v1.16.
COM_RC_LOSS_T	0.5 s	RC counted as lost after 0.5 s without input	✅	-	Default 0.5 s. Time without a new setpoint from the RC or a joystick after which the connection is considered lost. It must be short, because the vehicle keeps using the last supplied setpoint until the timeout triggers.
COM_RC_OVERRIDE	3	Stick override in auto and offboard modes	❌	High	Default 1 (auto modes only). Bit 0 = auto, bit 1 = offboard.
COM_RC_STICK_OV	30 %	Stick movement past 30 % hands control to the pilot	✅	-	Default 30 %. The threshold for COM_RC_OVERRIDE: when the sticks move more than this, PX4 gives control back to the pilot in Position mode. As I read ManualControl.cpp, it is compared against how fast a stick moves. Reasonable as is, but Max reports that it is reworked in PX4 1.18 (not verified by me), so re-check its name and meaning after upgrading to 1.18.
COM_RCL_EXCEPT	7	Offboard, Mission, and Hold modes	❌	-	Default 0 (no exceptions). Bitmask to specify where to ignore RC loss and not trigger the RC loss failsafe specified in NAV_RCL_ACT. 7 means RC is optional in Offboard, Mission, and Hold modes. Required for multi-agent setups since we only have one RC, but consider reverting to default when testing single-agent; RC then becomes required again.
COM_SPOOLUP_TIME	1.0 s	1.0 s spool-up after arming	✅	-	Default 1.0 s. The minimum time from arming the motors until the vehicle can be moved: the motors and propellers spool up to idle before being commanded faster, and the ESCs and smart batteries have time for their failure checks. Commands to move the vehicle are not applied until this time has passed after arming. No motivation to change.
COM_TAKEOFF_ACT	0	Hold mode	✅	-	Default 0 (Hold mode). Mode to change into after successful takeoff. Not much flexibility here, so this is why global position estimates are needed as explained in the reasoning for EKF2_HGT_REF.
COM_VEL_FS_EVH	1 m/s	Failsafe above 1 m/s horizontal velocity error	✅	-	Default 1 m/s. The horizontal velocity error (EVH) above which PX4 triggers a failsafe, with the same factor of 2.5 between validating and invalidating as COM_POS_FS_EPH. No motivation to change.
COM_WIND_MAX	−1 m/s	High wind failsafe disabled	✅	-	Default −1 (disabled). The estimated wind speed above which the action in COM_WIND_MAX_ACT is triggered. No motivation to change; just do not fly in wind.
COM_WIND_MAX_ACT	0	No high wind action	✅	-	Default 0 (None). The action taken at COM_WIND_MAX (1 Warning, 2 Hold, 3 Return, 4 Terminate, 5 Land). No motivation to change.
COM_WIND_WARN	−1 m/s	Wind warning disabled	✅	-	Default −1 (disabled). When enabled, a warning is sent every minute while the estimated wind speed is above this value. No motivation to change.

EKF2: Estimator

The EKF2_*_POS_* offsets (GPS, IMU, optical flow, rangefinder, external vision) are in the FRD body frame, measured from the center of gravity (CG): X is forward, Y is right, and Z is down. A sensor above the CG therefore has a negative Z.

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
EKF2_EV_CTRL	0	External vision fusion disabled	✅	-	Default 0. Only relevant if a motion-capture system outdoors or a computer-vision camera aids the position estimate. This quad and workspace has neither. The sample drone had 15 (all four bits: horizontal position, vertical position, 3D velocity, yaw); Max is surprised by that and does not know who set it. Per the v1.16 source this is not limited to mocap or cameras: it applies to any vision/odometry input PX4 receives (for example MAVLink VISION_POSITION_ESTIMATE or ODOMETRY, which a companion computer could send).
EKF2_EV_DELAY	0 ms	No external vision delay	✅	-	Default 0 ms. Delay of the external vision estimate relative to the IMU. Only relevant if a motion-capture system or a computer-vision camera aids PX4 in estimating pose and twist, which this vehicle does not use (EKF2_EV_CTRL = 0); RTK makes such sources likely unnecessary anyway. Requires reboot.
EKF2_EV_NOISE_MD	0	EV-reported variance	✅	-	Default 0 (the measurement noise comes from the vision message, with the EV noise parameters as a lower bound; 1 uses the noise parameters directly). Only relevant if a motion-capture system or a computer-vision camera aids PX4 in estimating pose and twist, which this vehicle does not use (EKF2_EV_CTRL = 0); RTK makes such sources likely unnecessary anyway.
EKF2_EV_POS_X	0.000 m	Vision sensor at the CG on X	✅	-	Default 0.0. Position of the vision sensor focal point in the body frame. Only relevant if a motion-capture system or a computer-vision camera aids PX4 in estimating pose and twist, which this vehicle does not use (EKF2_EV_CTRL = 0); RTK makes such sources likely unnecessary anyway.
EKF2_EV_POS_Y	0.000 m	Vision sensor at the CG on Y	✅	-	Default 0.0. Position of the vision sensor focal point in the body frame. Only relevant if a motion-capture system or a computer-vision camera aids PX4 in estimating pose and twist, which this vehicle does not use (EKF2_EV_CTRL = 0); RTK makes such sources likely unnecessary anyway.
EKF2_EV_POS_Z	0.000 m	Vision sensor at the CG on Z	✅	-	Default 0.0. Position of the vision sensor focal point in the body frame. Only relevant if a motion-capture system or a computer-vision camera aids PX4 in estimating pose and twist, which this vehicle does not use (EKF2_EV_CTRL = 0); RTK makes such sources likely unnecessary anyway.
EKF2_EV_QMIN	0	No minimum vision quality	✅	-	Default 0 (range 0 to 100). Minimum quality metric, an optional field some VIO systems provide, for external vision to be started and fused. Only relevant if a motion-capture system or a computer-vision camera aids PX4 in estimating pose and twist, which this vehicle does not use (EKF2_EV_CTRL = 0); RTK makes such sources likely unnecessary anyway.
EKF2_EVV_NOISE	0.1 m/s	Vision velocity noise 0.1 m/s	✅	-	Default 0.1 m/s. Measurement noise for vision velocity measurements, used to lower bound or replace the uncertainty in the message. No motivation to change, and it is not relevant without external vision such as mocap anyway.
EKF2_GPS_CHECK	1023	All GPS quality checks enabled	✅	High	Default 1023, and it is needed. The 10 bits are satellite count, PDOP, EPH, EPV, speed accuracy, horizontal drift, vertical drift, horizontal speed offset, vertical speed offset, and spoofing. Most tests so far were done with 245 (satellite count, EPH, speed accuracy, horizontal and vertical drift, horizontal speed offset) and without RTK, because Max did not yet know what he was doing.
EKF2_GPS_CTRL	7	Lon/lat + altitude + 3D velocity fusion	✅	High	Default 7. Dual-antenna heading (bit 3) stays off.
EKF2_GPS_DELAY	110 ms	GPS delay 110 ms	✅	-	Default 110 ms. GPS measurement delay relative to the IMU measurements. No motivation to change. Requires reboot.
EKF2_GPS_POS_X	0.010 m	GPS antenna 0.010 m forward of CG	❌	-	Default 0.0. Measured antenna offset by unknown party.
EKF2_GPS_POS_Y	0.000 m	GPS antenna on centerline	✅	-	Default 0.0.
EKF2_GPS_POS_Z	−0.217 m	GPS antenna 0.217 m above CG (negative Z is up in FRD)	❌	-	Default 0.0. Set by Max on 2026-10-27.
EKF2_HGT_REF	1	GPS is the height reference	✅	High	Default 1. This was contentious. The Astro's GPS vertical fix is much better than the Homebrew's, so without RTK the Homebrew tends to wander vertically when holding position in Position Mode (e.g., 0.5-1 m). Choosing 2 (range sensor) looks like a fix but makes global_position_invalid always true, so transitions into modes such as Hold are declined. This has the consequene that the drone gets stuck taking off (can never transition to Hold from Takeoff) or that it cannot land when using a ROS 2 teleop node if the code first dictates a transition to Hold mode. Hence: use RTK for better estimates and keep 1 so global_position_invalid stays false. (This is the lab's observation; I have not verified the global_position_invalid behaviour in the PX4 source. The source does say the range-sensor option should only be used over a flat surface, because the local NED origin then moves with ground level.)
EKF2_IMU_POS_X	0.0587 m	IMU 0.0587 m forward of CG	❌	-	Default 0.0. Max does not know who set this or where the value came from.
EKF2_IMU_POS_Y	0.000 m	IMU on centerline	✅	-	Default 0.0.
EKF2_IMU_POS_Z	−0.051 m	IMU 0.051 m above CG (negative Z is up in FRD)	❌	-	Default 0.0. Set by Max on 2026-10-27.
EKF2_MAG_CHECK	1	Magnetic field strength check only	✅	-	Default 1 (strength only). Bitmask of the checks that decide whether the magnetometer data is valid: bit 0 field strength (tolerance EKF2_MAG_CHK_STR, 0.2 gauss), bit 1 field inclination (EKF2_MAG_CHK_INC, 20 degrees), bit 2 wait for GNSS to provide the theoretical strength and inclination from the World Magnetic Model (WMM). If GNSS data is received the field is compared with the WMM, otherwise with an average value. The check is useful to reject occasional hard-iron disturbances, and with COM_ARM_MAG_STR = 1 a failed check denies arming. Max would enable all the checks (7), but everything works and he has never broken a magnetometer in a crash, so there is no motivation to move away from the default.
EKF2_MIN_RNG	0.01 m	Expected ground range 0.01 m	❌	-	Default 0.1 m. The range finder reading the estimator assumes when the vehicle is on the ground and not moving, and the range finder returns invalid data or none, for example because it is inside its minimum measurement distance. The terrain estimator then still has a terrain height at the start of flight. Max applies 0.01 m (the lowest allowed value) early, because it is expected to become the default in PX4 1.18 (not verified by me).
EKF2_MULTI_IMU	3	Run 3 EKFs, one per IMU	❌	-	Default 0 (disabled). The flight controller has 3 IMUs inside, and letting PX4 pick the best estimate among them is a good idea. Requires SENS_IMU_MODE = 0. Requires reboot. PX4 only rewrites this value itself when it is outside 1 to 4 while SENS_IMU_MODE is 0.
EKF2_MULTI_MAG	0	Multi-EKF magnetometers disabled	✅	-	Default 0 (disabled). Maximum number of magnetometers to use for Multi-EKF; it requires SENS_MAG_MODE = 0 and a reboot. Left disabled because, unlike the IMUs, Max reports that the Cube does not have multiple magnetometers. The Here4 also provides a compass over DroneCAN (UAVCAN_SUB_MAG), so PX4 sees more than one. As far as I can tell, the sensors module chooses between them by priority and health (see the CAL_MAGn_PRIO parameters), not through UAVCAN_ENABLE. Max thinks both are reasonably accurate but is not sure which one is in use. If magnetometer issues appear, this is a good place to start.
EKF2_OF_CTRL	1	Optical flow fusion enabled	✅	-	Default is 1 in v1.16. Kept explicit so flow is always used. Flow data arrives over CAN (see UAVCAN_SUB_FLOW).
EKF2_OF_POS_X	0.04440 m	Flow sensor 0.0444 m forward of CG	❌	-	Default 0.0. Sensor mounting offset.
EKF2_OF_POS_Y	0.06670 m	Flow sensor 0.0667 m right of CG	❌	-	Default 0.0. Sensor mounting offset.
EKF2_OF_POS_Z	0.05080 m	Flow sensor 0.0508 m below CG	❌	-	Default 0.0. Sensor mounting offset.
EKF2_REQ_EPH	3.0 m	Maximum 3.0 m horizontal position error to use GPS	✅	-	Default 3.0 m (range 2 to 100). Maximum horizontal position error (EPH) the GPS may report for it to be used (bit 2 of EKF2_GPS_CHECK). Active because EKF2_GPS_CHECK = 1023. This threshold does not require RTK by itself, so the offboard code should land immediately, or refuse to arm, whenever the GPS fix type is not 6 (RTK fixed).
EKF2_REQ_EPV	5.0 m	Maximum 5.0 m vertical position error to use GPS	✅	-	Default 5.0 m (range 2 to 100). Maximum vertical position error (EPV) the GPS may report for it to be used (bit 3 of EKF2_GPS_CHECK). Active because EKF2_GPS_CHECK = 1023. This threshold does not require RTK by itself, so the offboard code should land immediately, or refuse to arm, whenever the GPS fix type is not 6 (RTK fixed).
EKF2_REQ_HDRIFT	0.1 m/s	Maximum 0.1 m/s horizontal drift to use GPS	✅	-	Default 0.1 m/s (range 0.1 to 1.0, so this is also the strictest allowed value). Maximum horizontal drift speed, used for the horizontal position drift and horizontal speed offset checks (bits 5 and 7 of EKF2_GPS_CHECK). The drift and offset checks only run when the vehicle is on the ground and stationary. Active because EKF2_GPS_CHECK = 1023. This threshold does not require RTK by itself, so the offboard code should land immediately, or refuse to arm, whenever the GPS fix type is not 6 (RTK fixed).
EKF2_REQ_NSATS	6	At least 6 satellites to use GPS	✅	-	Default 6 (range 4 to 12). Minimum satellite count for the GPS to be used (bit 0 of EKF2_GPS_CHECK). Active because EKF2_GPS_CHECK = 1023. This threshold does not require RTK by itself, so the offboard code should land immediately, or refuse to arm, whenever the GPS fix type is not 6 (RTK fixed).
EKF2_REQ_PDOP	2.5	Maximum PDOP 2.5 to use GPS	✅	-	Default 2.5 (range 1.5 to 5.0). Maximum position dilution of precision for the GPS to be used (bit 1 of EKF2_GPS_CHECK). Active because EKF2_GPS_CHECK = 1023. This threshold does not require RTK by itself, so the offboard code should land immediately, or refuse to arm, whenever the GPS fix type is not 6 (RTK fixed).
EKF2_REQ_SACC	0.5 m/s	Maximum 0.5 m/s speed accuracy to use GPS	✅	-	Default 0.5 m/s (range 0.5 to 5.0, so this is also the strictest allowed value). Maximum speed accuracy the GPS may report for it to be used (bit 4 of EKF2_GPS_CHECK). No motivation to change.
EKF2_REQ_VDRIFT	0.2 m/s	Maximum 0.2 m/s vertical drift to use GPS	✅	-	Default 0.2 m/s (range 0.1 to 1.5). Maximum vertical drift speed, used for the vertical position drift and vertical speed offset checks (bits 6 and 8 of EKF2_GPS_CHECK). Like the horizontal ones, these only run when the vehicle is on the ground and stationary. No motivation to change.
EKF2_RNG_A_HMAX	5.0 m	Range aid up to 5.0 m height	✅	-	Default 5.0 m (range 1 to 10). Maximum height above ground for the conditional range aid (EKF2_RNG_CTRL = 1): above it the estimator stops fusing the range finder for height.
EKF2_RNG_A_VMAX	1.0 m/s	Range aid up to 1.0 m/s horizontal speed	✅	-	Default 1.0 m/s (range 0.1 to 2). Maximum horizontal speed for the conditional range aid (EKF2_RNG_CTRL = 1): above it the estimator stops fusing the range finder for height.
EKF2_RNG_CTRL	1	Range finder enabled (conditional mode)	✅	High	Default 1. Range aiding is used at low speed and low altitude (takeoff/landing).
EKF2_RNG_POS_X	−0.00635 m	Rangefinder 0.00635 m behind CG	❌	-	Default 0.0. Sensor mounting offset.
EKF2_RNG_POS_Y	0.0539 m	Rangefinder 0.0539 m right of CG	❌	-	Default 0.0. Sensor mounting offset.
EKF2_RNG_POS_Z	0.114 m	Rangefinder 0.114 m below CG	❌	-	Default 0.0. Sensor mounting offset.

FD: Failure Detector

All FD_ACT_* parameters stay at their defaults, and the check is on by default. If the motors do not draw the small amount of current expected for the commanded throttle, PX4 treats that as a motor failure and warns accordingly (the reaction is set by COM_ACT_FAIL_ACT, which is warning only here). The check works from ESC current, so it can only trigger if the ESCs report current telemetry; the notes for COM_ARM_CHK_ESCS say these ESCs do not, which would make this check inert on this vehicle (my inference; not verified in the source).

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
FD_ACT_EN	1	Actuator failure check enabled	✅	-	Default 1 (enabled). The failure detector verifies that each motor consumes a minimum amount of ESC current per throttle level; otherwise it indicates a motor failure. Leave at default. Requires reboot.
FD_ACT_MOT_C2T	2.0 A/%	Current-to-throttle threshold 2.0 A/%	✅	-	Default 2.0 (range 0 to 50). A motor failure triggers only below this ESC current per throttle value. Leave at default.
FD_ACT_MOT_THR	0.2	Motor failure only above 20 % throttle	✅	-	Default 0.2 (normalized 0 to 1, not percent). A motor failure is only evaluated above this throttle value. Leave at default.
FD_ACT_MOT_TOUT	100 ms	Violation must last 100 ms	✅	-	Default 100 ms (range 10 to 10000). The throttle threshold and the current-to-throttle threshold must both be violated for this long before a motor failure triggers. Leave at default.

GF: Geofence

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
GF_ACTION	5	Land mode on geofence violation	❌	-	Default 2 (Hold mode). Land immediately rather than hover.
GF_MAX_VER_DIST	0 m	Disabled	✅	-	Default 0 (disabled). Do not use this feature. Because the GPS fix moves during the 1-10 minute initial RTK fix, the relative altitude (relative to the fix when it first boots) will make the quadcopter think it's all over the place. Since you cannot reset the home position without arming, using this feature to prevent the quadcopter from hitting the net as an extra safety feature is moot. Just use CBFs. This feature would interfere with CBF offboard code anyways. If not using RTK (you should really just use it), the estimates are likely not good enough to prevent you from hitting the net. And, PX4's geofence does not take into account for instance the speed at which you approach a geofence, so it's not even enforceable as a never-cross-this boundary.

GPS: Serial GPS

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
GPS_1_CONFIG	0	Serial GPS driver disabled	❌	-	Default 201 (GPS 1). The GPS is the Here4 on DroneCAN, so the serial GPS driver stays off.

MAN: Manual Control

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
MAN_ARM_GESTURE	0	Stick arm/disarm gesture disabled	❌	-	Default 1 (enabled). Prevents accidental arming/disarming by stick position.
MAN_KILL_GEST_T	−1	Kill stick gesture disabled	✅	-	Default −1 (negative value disables the feature).

MAV: MAVLink

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
MAV_0_CONFIG	101	MAVLink instance 0 on TELEM 1	✅	-	Default 101 (TELEM 1). The QGC telemetry radio connects here. Requires reboot. If torque-level control is ever wanted, note that (per Max, not verified by me) MAVROS does not support torque-level commands but uXRCE-DDS does, while RTK is not possible over uXRCE-DDS because there is no topic for it yet. Torque-level control plus RTK would therefore need uXRCE-DDS and MAVROS running together. That would need a third serial port, because TELEM 1 and TELEM 2 are taken by the QGC radio and the Jetson link, and giving up the QGC radio is extremely dangerous for a torque-level offboard flight. Options are to wait until uXRCE-DDS supports RTK or MAVROS supports torque-level control, to write custom PX4 topics for RTK over uXRCE-DDS, or to solder a new cable and run uXRCE-DDS on another port such as GPS 2 (not tried).
MAV_1_CONFIG	102	MAVLink instance 1 on TELEM 2	❌	High	Default 0 (disabled). The FTDI-to-USB cable to the Jetson connects to the flight controller here. Requires reboot.
MAV_1_FLOW_CTRL	2	Serial flow control auto-detected	✅	-	Default 2. The Jetson link. This setting tells PX4 to auto-detect flow control; PX4 does not write the parameter itself. Use 0 or 1 only if auto-detection fails. Requires reboot.
MAV_1_FORWARD	0	No message forwarding from the Jetson link	✅	-	Default 0. Broadcast messages (or ones aimed at another system) arriving on the Jetson link are not forwarded to the other MAVLink links. Requires reboot.
MAV_1_MODE	2	Onboard message set	✅	-	Default 2 (Onboard). The set of streamed messages on the Jetson link is the one meant for a companion computer. Requires reboot.
MAV_1_RATE	0 B/s	Rate limit chosen from the baud rate	✅	-	Default 0. With 0, PX4 uses half the theoretical bandwidth, baud/20 bytes per second; at 921600 baud that is 46080 B/s. PX4 does not write the parameter itself. Requires reboot.
MAV_PROTO_VER	2	Always use MAVLink 2	❌	-	Default 0 (start with MAVLink 1 and switch to 2 if the GCS sends version 2). Forces MAVLink 2.0 instead of 1.0. Not super critical; revert to the default if there are problems.
MAV_SYS_ID	TBD (2–249)	Unique number per homebrew vehicle	❌	High	Default 1. Never use 1 (every Astro requires 1 and it can't be changed). Choosing 1 will cause ROS 2 topic to intermingle between the Astro and Homebrew despite being namespaced. Must be unique. Range 1–250; never pick 250. Requires reboot.
MAV_TYPE	2	Quadrotor	✅	-	MC default 2 (metadata 0, generic micro air vehicle, overridden by rc.mc_defaults). The airframe type announced over MAVLink. Not super critical.

MC: Multicopter Autotune

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
MC_AIRMODE	0	Air-mode disabled	✅	High	Default 0 (disabled). Air-mode changes which commands are prioritized when the controller is saturating. Disabled is what Max recommends and has tested with.
MC_AT_EN	1	Autotune module enabled	❌	-	Default 0 (disabled). Allows autotuning the control cascade from QGC. This does not mean the quad tunes continuously in flight. Do not run it unless there is a reason to suspect poor control performance, which there really should not be.
MC_BAT_SCALE_EN	1	Battery power level scaler enabled	❌	High	Default 0 (disabled). This compensates for the voltage drop of the battery over time by attempting to normalize performance. It is important so that experiments run on a low battery perform similarly to a nearly full battery.

MIS: Mission

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
MIS_TAKEOFF_ALT	2.5 m	Take off to 2.5 m from ground level	✅	-	Default 2.5 m. Take off to 2.5 m from ground level

MPC: Multicopter Position Control

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
MPC_LAND_RC_HELP	0	Stick nudging during Land disabled	✅	-	Default 0. Deliberately left at default. Enabling it lets the sticks move the quad horizontally and yaw it during PX4's Land and Descend modes, and scales the descent speed with the throttle stick (full up stops the descent, centered is MPC_LAND_SPEED, full down is double). The trade-off and collisions: (1) the v1.16 description says stick override of auto modes must be disabled for this to work, which collides with COM_RC_OVERRIDE = 3; with override on, a fast stick movement in an auto mode switches to Position mode instead of nudging, and COM_RC_STICK_OV sets how sensitive that is. Max prefers the override. (2) The throttle stick on a Taranis QX7 does not spring back to center, so an RC left on with throttle low would double the descent speed of every Land, including a battery failsafe Land (COM_LOW_BAT_ACT) (my inference from the description). (3) It has no effect in Offboard, so it does not change Jetson landings, and it needs a valid RC, so it does nothing on a quad with no RC. (4) MPC_LAND_RADIUS (default 1000 m) limits how far the nudging can move the quad from the landing point.
MPC_THR_HOVER	0.55	Hover thrust 0.55	❌	High	Default 0.5. Works well. Increase it if adding a payload. Do not exceed 0.7.

NAV: Navigator

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
NAV_DLL_ACT	0	Disabled (no GCS-loss failsafe)	✅	High	Default 0. Removes the need for QGC to stay connected. Required for multi-agent setups.
NAV_RCL_ACT	3	Land mode on RC loss	❌	High	Default 2 (Return mode). Land in place instead of returning.

PLD: Precision Landing

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
PLD_SRCH_ALT	2.5 m	Climb to 2.5 m above home when searching for the landing target	❌	-	Default 10 m. Our flight space has a net at 8 m.

PWM: Motor Outputs

These are what the motors for this quadcopter need. Output functions 101 to 104 are Motor 1 to Motor 4.

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
PWM_MAIN_FUNC1	101	Motor 1	❌	-	Default 0 (disabled). What the motors for this quadcopter need.
PWM_MAIN_FUNC2	102	Motor 2	❌	-	Default 0 (disabled). What the motors for this quadcopter need.
PWM_MAIN_FUNC3	103	Motor 3	❌	-	Default 0 (disabled). What the motors for this quadcopter need.
PWM_MAIN_FUNC4	104	Motor 4	❌	-	Default 0 (disabled). What the motors for this quadcopter need.
PWM_MAIN_MAX1	1900	Output 1 maximum 1900 µs	❌	-	Default 2000. What the motors for this quadcopter need.
PWM_MAIN_MAX2	1900	Output 2 maximum 1900 µs	❌	-	Default 2000. What the motors for this quadcopter need.
PWM_MAIN_MAX3	1900	Output 3 maximum 1900 µs	❌	-	Default 2000. What the motors for this quadcopter need.
PWM_MAIN_MAX4	1900	Output 4 maximum 1900 µs	❌	-	Default 2000. What the motors for this quadcopter need.
PWM_MAIN_MIN1	1100	Output 1 minimum 1100 µs	❌	-	Default 1000. What the motors for this quadcopter need.
PWM_MAIN_MIN2	1100	Output 2 minimum 1100 µs	❌	-	Default 1000. What the motors for this quadcopter need.
PWM_MAIN_MIN3	1100	Output 3 minimum 1100 µs	❌	-	Default 1000. What the motors for this quadcopter need.
PWM_MAIN_MIN4	1100	Output 4 minimum 1100 µs	❌	-	Default 1000. What the motors for this quadcopter need.

RC: Radio Control

These are the Taranis QX7 template needed to use the radio with this quadcopter.

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
RC_CHAN_CNT	18	18 RC channels saved at RC calibration	❌	-	Default 0. Taranis QX7 template needed to use this radio with the quadcopter.
RC_KILLSWITCH_TH	0.75	Kill switch threshold 0.75	✅	-	Default 0.75. Fine as is.
RC_MAP_ARM_SW	9	Arm switch on RC channel 9	❌	-	Default 0 (unassigned). Taranis QX7 template needed to use this radio with the quadcopter.
RC_MAP_AUX1	0	AUX1 unassigned	✅	-	Default 0 (unassigned). Channel 10 is the kill switch (RC_MAP_KILL_SW), so AUX1 must not also use it.
RC_MAP_FLTMODE	5	Flight mode selection on RC channel 5	❌	-	Default 0 (unassigned). Taranis QX7 template needed to use this radio with the quadcopter.
RC_MAP_KILL_SW	10	Kill switch on RC channel 10	❌	-	Default 0 (unassigned). Channel 10 is the right switch on the Taranis QX7.
RC_MAP_PITCH	2	Pitch on RC channel 2	❌	-	Default 0 (unassigned). Taranis QX7 template needed to use this radio with the quadcopter.
RC_MAP_ROLL	1	Roll on RC channel 1	❌	-	Default 0 (unassigned). Taranis QX7 template needed to use this radio with the quadcopter.
RC_MAP_THROTTLE	3	Throttle on RC channel 3	❌	-	Default 0 (unassigned). Taranis QX7 template needed to use this radio with the quadcopter.
RC_MAP_YAW	4	Yaw on RC channel 4	❌	-	Default 0 (unassigned). Taranis QX7 template needed to use this radio with the quadcopter.

RTL: Return Mode

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
RTL_DESCEND_ALT	2 m	2 m (≈ 6.6 ft)	❌	-	MC default 10 m (metadata 30 m, overridden by rc.mc_defaults). The net is 8 m tall, so this keeps the vehicle clear of it.
RTL_RETURN_ALT	2 m	2 m (≈ 6.6 ft)	❌	-	MC default 30 m (metadata 60 m, overridden by rc.mc_defaults). The net is 8 m tall, so this keeps the vehicle clear of it.

SDLOG: SD Logging

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
SDLOG_PROFILE	1	Default logging set only	✅	High	Default 1. Our SD cards have a limited maximum write rate (5 MB/s). More logging helps advanced debugging, but the SD cards we have now cannot keep up with more writes than SDLOG_PROFILE = 1. See Known Issues. Requires reboot.

SENS: Sensors

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
SENS_BOARD_ROT	2	Autopilot board rotated Yaw 90°	❌	-	Default 0 (no rotation). Required for how the CubePilot is placed in the case. This setting tells PX4 the arrow on the CubePilot points to the drone's starboard (clockwise is positive). Requires reboot.
SENS_EN_PMW3901	0	Local PMW3901 optical flow driver disabled	✅	-	Default 0 (disabled). This enables a PMW3901 wired to the Cube's SPI bus. The optical flow sensor is on CAN instead (see UAVCAN_SUB_FLOW).
SENS_EN_SF0X	8	LW20/c	❌	-	Default 1 (SF02). Selects the model of the serial LightWare lidar. It only appears when SENS_SF0X_CFG is not disabled, so it does not need to be set (and is not in the .params file).
SENS_EN_SF1XX	6	SF/LW20/c	❌	-	Default 0 (disabled). The LW20/c on I2C is the only distance sensor used for estimation. Requires reboot.
SENS_FLOW_ROT	0	No rotation	✅	-	Default 0 (no rotation). Rotation of the optical flow sensor relative to the airframe. It seems to work fine at 0, but Max was not able to verify which direction the optical flow sensor faces.
SENS_IMU_MODE	0	Sensors hub does not select the primary IMU (needed for multi-EKF)	❌	-	Default 1 (publish primary IMU selection). Required by EKF2_MULTI_IMU = 3: the v1.16 description of EKF2_MULTI_IMU says "Requires SENS_IMU_MODE 0". Requires reboot.
SENS_SF0X_CFG	0	Disabled	✅	-	Default 0 (disabled). Serial port configuration for the LightWare lidar (that is, UART). Since the LW20/c is on I2C (SENS_EN_SF1XX), this stays disabled to prevent PX4 from getting confused.

SEP: Septentrio GPS

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
SEP_PORT1_CFG	0	Septentrio driver disabled	✅	-	Default 0 (disabled). The GPS is the Here4 on DroneCAN, so the Septentrio serial driver stays off.

SER: Serial Ports

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
SER_TEL1_BAUD	57600	TELEM 1 at 57600 baud	✅	-	Default 57600. The QGC telemetry radio on TELEM 1 (MAV_0_CONFIG); the radio must use the same baud rate. Requires reboot.
SER_TEL2_BAUD	921600	TELEM 2 at 921600 baud	✅	-	Default 921600. The Jetson link on TELEM 2 (MAV_1_CONFIG). Requires reboot.

SF1XX: LightWare Lidar (I2C)

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
SF1XX_MODE	1	Enabled	✅	-	Default 1 (enabled). Operation mode of the LightWare lidar driver. The other option, 2 (disabled during VTOL fast forward flight), is for VTOL vehicles and is not relevant here.

SYS: System

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
SYS_AUTOSTART	4001	Generic Quadcopter (airframe 4001_quad_x)	❌	-	Default 0 (none). Uses the multicopter for PX4 default parameters. Requires reboot.
SYS_HAS_BARO	1	Barometer expected	✅	-	Default 1 (on). Pre-flight check for a barometer; if disabled, the preflight checks do not look for one. Requires reboot.
SYS_HAS_GPS	1	GPS expected	✅	-	Default 1 (on). Controls whether the vehicle has a GPS. If disabled, the sensors hub does not process sensor_gps at all and GPS is not available to the rest of the system, so this must stay on. Requires reboot.
SYS_HAS_MAG	1	One magnetometer expected	✅	-	Default 1 (on). Number of magnetometers the pre-flight check requires: 0 means none is expected, and 1 to N require N magnetometers to be present. Requires reboot.
SYS_HAS_NUM_DIST	1	One distance sensor required	❌	High	Default 0 (check disabled). The preflight check fails if fewer than this number of distance sensors with valid data are present. Set to 1 so that a missing or silent LW20/c is caught before flight.
SYS_HAS_NUM_OF	1	One optical flow sensor required	❌	High	Default 0 (check disabled). The preflight check fails if fewer than this number of optical flow sensors with valid data are present (the maximum is 1). Set to 1 so that a missing or silent flow sensor is caught before flight.
SYS_USB_AUTO	2	MAVLink starts on USB right away	✅	-	Default 2 (MAVLink). Per the PX4 serial configuration documentation, it selects whether the USB port runs no particular protocol, auto-detects the protocol, or is set to MAVLink. With MAVLink, PX4 starts MAVLink on USB as soon as USB is available instead of waiting to receive data first. Keep it at default so the USB link works right away.

THR: Thrust Model

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
THR_MDL_FAC	0.3	Thrust model factor 0.3 (30% quadratic term)	❌	High	Default 0. Usually determined by a bench thrust test. This value is a good guess that works in flight, so there is no motivation to change it.

UAVCAN: DroneCAN

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
UAVCAN_ENABLE	2	Sensors, automatic config	❌	-	Default 0 (disabled). DroneCAN must be on for the Here4 and the flow/rangefinder node. Value 2 allocates node IDs dynamically. Requires reboot.
UAVCAN_PUB_RTCM	1	Publish RTCM stream	❌	-	Default 0. Required for PX4 to accept RTK corrections over DroneCAN. Requires reboot.
UAVCAN_RNG_MAX	100 m	Rangefinder maximum range 100 m	❌	-	Default 999 m. The maximum valid range accepted from a rangefinder connected over DroneCAN. 100 m is the rated maximum range of the LW20/c. As far as I can tell from the description, it only applies to a DroneCAN rangefinder (UAVCAN_SUB_RNG, which is 0 here) and not to the LW20/c on I2C.
UAVCAN_RNG_MIN	0 m	Rangefinder minimum range 0 m	✅	-	Default 0 m. The minimum valid range accepted from a rangefinder connected over DroneCAN. Technically the rated minimum for the LW20/c is 0.2 m, but this works so it is fine. The same caveat as for UAVCAN_RNG_MAX applies.
UAVCAN_SUB_FLOW	1	Optical flow subscription enabled	❌	High	Default 0. The optical flow sensor is on the CAN bus. This subscribes to its flow data only; its distance sensor is controlled separately by UAVCAN_SUB_RNG. Requires reboot.
UAVCAN_SUB_GPS	1	GPS subscription enabled	✅	-	Default 1. The Here4 provides GPS over DroneCAN. Requires reboot.
UAVCAN_SUB_IMU	0	IMU subscription disabled	✅	-	Default 0. No external IMU on CAN; the IMUs are inside the Cube. Requires reboot.
UAVCAN_SUB_MAG	1	Magnetometer subscription enabled	✅	-	Default 1. The Here4 provides a compass over DroneCAN. Max is not sure this compass is actually the one being used (see EKF2_MULTI_MAG). Requires reboot.
UAVCAN_SUB_RNG	0	Range finder subscription disabled	✅	-	Default 0. The only distance sensor is the LW20/c on I2C. The optical flow sensor's own distance sensor must never be used for estimation. Requires reboot.

USB: USB MAVLink

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
USB_MAV_MODE	2	Onboard message set on USB	✅	-	Default 2 (Onboard). The MAVLink profile used on the USB port when MAVLink is set or detected (SYS_USB_AUTO). The PX4 documentation says the USB port is by default a MAVLink port with the onboard profile meant for companion computers, the same message set as MAV_1_MODE.

uXRCE: A MAVROS Alternative

Parameter Name	Setting (Raw)	Setting (Word)	Is Default (MC)	Relevance	Reason
UXRCE_DDS_CFG	0	Disabled	✅	-	Default 0. Turns on the UXRCE-DDS Client (alternative to MAVROS that allows torque-level control but foregoes RTK).
UXRCE_DDS_DOM_ID	0	ROS Domain ID	✅	-	Default 0. Must match ROS setup.
UXRCE_DDS_PTCFG	2	Custom participant	❌	-	Default 0. Required if using discovery server. Needs a XML config and file on fs/microsd/etc/. This parameter only appears if UXRCE_DDS_CFG is not zero. Ignore if not using uXCRE.