Something is disabled

iNav may fail to perform some action as expected, typically arming or engaging waypoints. This articles documents the reasons for some of these events.

Arming disabled reasons

iNav will refuse to arm for the following reasons (e.g. from cli status):

Reason (CLI Mnemonic)	Bit Mask (Hex)	Explanation
FS	00000080	The RX is not recognised as providing a valid signal
ANGLE	00000100	The vehicle is not level as defined by the CLI small_angle setting
CAL	00000200	The pre-arm sensor calibration has not completed. The barometer is somewhat susceptible to lengthy calibration, which may be mitigated by the CLI setting baro_cal_tolerance, e.g. set baro_cal_tolerance = 500 (find a suitable value by experimentation).
OVRLD	00000400	The CPU load is excessive. May be caused by too an aggressive loop time setting.
NAV	00000800	Where the CLI setting nav_extra_arming_safety = ON is used, this may be caused by reasons shown in the table below
COMPASS	00001000	The compass is not calibrated. Perform the calibration procedure
ACC	00002000	The accelerometer is not calibrated. Perform the 6 point calibration procedure
ARMSW	00004000	The arm switch was engaged as the FC booted
HWFAIL	00008000	A required hardware device has failed / is not recognised (e.g. GPS, Compass, Baro)
BOXFS	00010000	A failsafe switch is engaged
KILLSW	00020000	A kill switch is engaged
RX	00040000	The RC link is not detected (RX not detected)
THR	00080000	The throttle setting is not a minimum
CLI	00100000	The CLI is active (note: you will always /unavoidably see this when in the CLI)
CMS	00200000	The CMS menu is active
OSD	00400000	The OSD menu is active
ROLL/PITCH	00800000	Roll and/or pitch is not centred
AUTOTRIM	01000000	Servo autotrim is engaged
OOM	02000000	The FC is out of memory
SETTINGFAIL	04000000	A CLI setting is out of range. The erroneous setting should be indicated in a CLI dump. If you can't then reset the offending setting, reflash with full chip erase and reapplying settings from scratch may help.
PWMOUT	08000000	PWM output error. Motor or servo output initialisation failed.
NOPREARM	10000000	PREARM is enabled and timed out
DSHOTBEEPER	20000000	DSHOTBEEPER is enabled and is active

Note: On older processors, just the bitmask is shown, which can be decoded by the numeric values in the table. A numeric value may be a combination of conditions, for example:

0x184000 = 00100000 + 00080000 + 00004000 (CLI active, throttle not at minimum, arm engaged)

The values are correct for iNav 4.0.0 as of 2021-12.

Navigation Unsafe reasons

Requires that a navigation mode (which includes failsafe RTH) is configured

Navigation Unsafe
The GPS has insufficient satellites (this is checked even if you disable GPS, but have a NAV mode configured in Modes tab)
A navigation switch is engaged (e.g.PH, WP, RTH)
First WP distance exceeded
Satellite quality is unacceptable: EPH/EPV > 10m (note the limit in the CLI inav_max_eph_epv is in cm, default 1000)
The WP mission contains an invalid JUMP sequence
The first waypoint is beyond the distance defined by the CLI setting nav_wp_safe_distance.

• nav_wp_safe_distance : The default is 100m (10000cm, as the value is entered in cm), 0 disables this check.

  # get nav_wp_safe_distance
  nav_wp_safe_distance = 10000
  Allowed range: 0 - 65000

• Invalid JUMP.

  • First item can't be JUMP (can't calculate 1st WP distance, impossible for backward jumps)
  • Can't jump to immediately adjacent WPs (pointless)
  • Can't jump beyond WP list (undefined behaviour)
  • Can only jump to geo-referenced WPs (otherwise, undefined behaviour)

Waypoints will not execute

The pilot thinks that they have loaded a waypoint mission, but the mission will not execute when the assigned switch is engaged.

• No mission is actually loaded into the FC. Note that waypints have to be in volatile memory (that is cleared on powercycle), not in EEPROM. If waypoints have been saved to EEPROM it is necessary to restore the WPs to volatile memory before the mission can be executed.

• The Fixed Wing aircraft is in MANUAL / PASSTHROUGH mode.

• The craft is currently executing RTH

RTH fails to engage

• The GPS signal is degraded (eph / epv exceed, CLI setting inav_max_eph_epv)

Diagnostics

Diagnosing arming failure and WP execution failure often requires the use of a tool external to the FC; the following may help:

• The iNav configurator displays reasons for arming failure

• A blackbox log provides post event diagnostics

• The iNav CLI (available from a terminal, the configurator and many ground-stations) displays arming disabled reasons:

  # status
  ...
  Arming disabled flags: NAV HWFAIL RX CLI

• A ground station may provide diagnostics, for example mwp provides an 'Arming Disabled' alert icon with 'popover' description / explanation, mission upload validation checks and 'first WP distance' exceeded warnings.

• Video explanation via https://quadmeup.com/troubleshooting-inav-why-inav-is-not-arming/

• Your favourite diagnostic tool / technique goes here

Postscript

For 'Navigation is unsafe', you may, of course set nav_extra_arming_safety = OFF; however there is a clue is in the name.