5. Troubleshooting

5.1 Alert Indications

The SIGMA25G has many alerts, warnings, and failure indicators.

All alerts, warnings, and failure indicators will be displayed in red text in the HUD dropout window on the ground station screen.

Alert	Description
Low Battery	Battery failsafe has triggered, should land immediately
No GPS Fix	Warns pilot that the GPS cannot get a satellite fix
Telemetry Lost	Warns pilot that the telemetry signal has been lost
High GPS HDOP	GPS signal quality is insufficient
Throttle Below Failsafe	Ground controller has lost connection to the vehicle
Gyro Calibration Failed	Failed to calibrate the IMUs on the vehicle
Mode Not Arm-able	Operator is attempting to arm the vehicle in a mode which does not allow arming
Rotor Not Spinning	Autopilot has detected an error attempting to run one or more motors
Vehicle is Leaning	Vehicle orientation is not suitable for take-off
Throttle Too High	Current throttle setting is too high to arm safely (could result in spontaneous take-off)
Safety Switch	Operator attempted to arm, but hardware arm-safety switch is engaged
Compass Calibration Running	Cannot arm, currently calibrating the compass
RC Not Calibrated	Ground control radio has not been calibrated for use with the vehicle
Barometer Not Healthy	Barometer is experiencing an error
Compass Not Healthy	Compass is experiencing an error
Compass Not Calibrated	Compass requires calibration
Compass Offsets Too High	Compass calibration has resulted in unusable offsets
Check Magnetic Field	Vehicle is near a metallic or magnetic object which is interfering with compass operation
Inconsistent Compass	Compass readings are determined to be erroneous
Check Geo Fence	Vehicle is outside of a defined fence area, not allowed to fly
Inertial Navigation System Not Calibrated	IMU calibration is needed
Accelerometers Not Healthy	IMU calibration is needed
Inconsistent Accelerometers	IMU calibration is needed
Gyros Not Healthy	IMU calibration is needed, or vehicle needs to be moved to an orientation matching the powered-up orientation
Check Board Voltage	Problem detected with power supplied to the autopilot
Inconsistent Gyros	IMU calibration is needed, or vehicle needs to be moved to an orientation matching the powered-up orientation
Check Max Angle	ANGLE_MAX parameter set to an in appropriate value
RC Failsafe	Ground controller has lost connection with the vehicle
Need GPS Lock	Operator is trying to arm vehicle in a mode where GPS lock is needed, and there is no GPS lock
EKF Home Variance	EKF has detected a difference between expected and actual home points
GPS Glitch	GPS readings indicate an error (e.g. multipathing) - GPS signal cannot be trusted
Waiting for Navigation Alignment	AP is initializing and not ready to launch
Altitude Disparity	GPS and barometer altitudes are reported to be substantially different, indicating a possible error
Vehicle Crash	AP has detected that the vehicle has collided with terrain or some other solid object
EKF Variance	EKF has detected uncertainty in GPS location, compass heading, IMU readings. Should not launch
Need Position Estimate	GPS needs to calculate an estimated position for the vehicle