Betaflight Setup: attitude, arming checks and calibration

The tab always builds Attitude, Arming, Calibration and Flight controller. Those four are the Betaflight Setup tab and the shared part of the INAV one. Calibration on both firmwares contains Calibrate accelerometer, Calibrate compass, and Reset settings to defaults. Disarm to calibrate is the card footer while the board is armed, and every calibration row stays disabled until you disarm.

INAV adds three things inside Calibration: the six-position accelerometer sheet instead of the single level capture, Calibrate optical flow, and the compass-zero, compass-gain and optical-flow-scale lines. INAV also adds the defaults card. That card is at the top when applied defaults are still unset, and at the bottom once a platform has been chosen. Betaflight does not show it. The Betaflight demo is firmware 4.5, MSP API 1.46, so its arming names are the 1.46 set described below.

The model uses the live roll, pitch and heading. Yaw on the model is the heading minus the Reset Z axis offset, which starts at zero. Pressing Reset Z axis copies the heading you have now into that offset. It is screen state only. It does not calibrate the compass and it does not write a board alignment. The numbers under the instruments do not use the offset: Heading is the board heading rounded to a whole degree, and Roll · Pitch is roll and pitch to one decimal, separated by a middle dot.

On INAV the card title prefers the model-preview name for the id the board reports, such as Quad X or Airplane, when FlySpark knows that id. Otherwise it uses the craft label. That title is a name for the 3D model. The frame chips you apply live on the mixer, not on this card. A heading indicator and an attitude indicator sit above the two readouts. If attitude has not arrived, the model area waits on a spinner.

Betaflight reads arming-disable flags and the count the firmware reports. FlySpark names them from the MSP API minor version. For API 1.46, which is what Betaflight 4.5 and the demo report, the names are No gyro, Failsafe active, RX link lost, Bad RX recovery, Failsafe switch, Runaway takeoff, Crash detected, Throttle not low, Not level (small angle), Boot grace time, Prearm switch off, CPU load too high, Calibrating, CLI open, CMS menu open, BST, MSP override, Paralyze, GPS rescue not ready, Rescue SW, No DShot telemetry, Reboot required, DShot bitbang, Accelerometer not calibrated and Motor protocol not set. The last flag in the board's own count is always labelled Arm switch was on at boot, whatever version it is.

API 1.47 adds Crash-flip mode, Altitude hold not ready and Position hold not ready. API 1.48 adds Autopilot not ready. Those names show up only when the connected firmware's API is that new. The 4.5 demo does not list them. A flag number past the known names, other than the last one, is shown as Blocker and its number.

INAV uses a different set, and only these blockers are chips: Failsafe system, Not level, Sensors calibrating, System overloaded, Navigation unsafe, Compass not calibrated, Accelerometer not calibrated, Arm switch was on, Hardware failure, Failsafe switch, Kill switch, RC link lost, Throttle not low, CLI open, CMS menu open, OSD menu open, Roll/pitch not centred, Servo autotrim, Out of memory, Invalid setting, PWM output error, Prearm switch off, DShot beeper and Landing detected. Ready to arm, the warning chips, and ARMED – motors live are the same three outcomes on both firmwares. ARM itself is assigned on the Modes tab. A receiver problem such as RX link lost or RC link lost is cleared from the Receiver tab, not by a button on Setup.

On Betaflight, Calibrate accelerometer sends one calibration and waits about two seconds, with a progress ring on the row. The subtitle tells you to place the aircraft level on a flat surface first. When it finishes, a snackbar says Accelerometer calibration finished. A failure names the error. Do this with props off and the board disarmed. The arming chip Accelerometer not calibrated clears only after the board accepts the result.

Calibrate compass is the same entry on Betaflight and INAV. The ready text tells you to keep away from metal, phones and power cables, with the battery connected but motors off, then press Start and turn the aircraft until the flight controller finishes. The expected time is in that sentence. Cancelling only closes the sheet; the flight controller finishes on its own. While it runs, the instruction asks you to rotate on all axes: spin it flat, roll it onto each side, point the nose up and down and turn it upside down, and to fill the map that still has gaps. The bar is labelled as a percent covered. At the end the sheet says Calibration finished and shows a quality of Excellent, Good, Fair or Poor, plus a hint about coverage or magnetic noise.

When the board reports offsets, the sheet prints Compass zero for X, Y and Z, and Compass gain when gain was returned. On a Betaflight build that cannot report the offsets without leaving MSP, the sheet says Betaflight before 2025.12 cannot report them that way, and to type get mag_calibration in the CLI. The 4.5 demo is in that older group. On INAV, if offsets are missing, the sheet says the flight controller did not report them. Separately, the Calibration card on INAV prints Compass zero, Compass gain and Optical flow scale after a refresh. Optical flow scale is the stored value divided by 256, shown to two decimal places. Those three lines are INAV only.

Calibrate optical flow is INAV only and runs for 30 seconds when a sensor is present. The subtitle says to hold it in the air for 30 seconds and tilt it to the sides without moving it horizontally, and that the sensor must see the ground the whole time. The row stays off when no optical flow sensor is detected. It does not appear on Betaflight.

The Flight controller card is a reading, not a form. Firmware is the variant and version. MSP API is major.minor. Target, Board and Craft appear when the board sent them. Loop time is in microseconds. CPU load is a percent when the status includes it. I²C errors is a count. Battery is voltage to two decimal places, and cell count with an S when the count is known. Current is amps to one decimal and the milliamp hours drawn. The sensor chips under the rows are the checklist for GYRO, ACC, BARO, MAG, GPS and RANGEFINDER, with GYRO omitted on INAV. A grey chip means that sensor is not in the status. GPS numbers beyond the chip, such as satellites, are on the GPS page.

Reset settings to defaults is the last calibration row on both firmwares. Confirming sends a full reset and then reboots and reconnects. The dialog tells you to back up first. Success says Settings reset to defaults. This wipes the configuration. It is not a sensor calibration.