Live gyro and accelerometer

Put the craft on the bench and watch the gyro. Roll, pitch and yaw should sit near 0 degrees per second. A line that jumps while nothing is touching the craft is vibration or a loose stack, not a rate you asked for. The hint on the gyro card says the same.

The accelerometer is the check that the board knows which way is down. Level and still, X and Y are near 0 g and Z is near 1 g. If Z is near 1 g but X or Y is far from 0, the board is tilted, or the accelerometer trim on the configuration tab is pulling it. A calibration on the Setup tab replaces that trim.

The chips above the graphs are the sensors this board reported. Gyro is always on. Accelerometer, compass, barometer and rangefinder light only when the status bit is set. A dark chip means the firmware does not see that sensor. Turning the hardware switch off on the configuration tab is a different step: that tells the firmware not to use a sensor it does have.

Roll is the first gyro line, then pitch, then yaw. Read one axis at a time. If only yaw jumps while the craft sits still, the stack is twisting, not the whole frame shaking. If all three jump together, something is vibrating the flight controller.

The compass graph is in gauss. Turn the craft and X and Y should swing. A compass that jumps when the motors spin is hearing the current in the battery wires. Move it, or twist those wires, before you trust a heading. Aligning an INAV compass and running its calibration sweep is the compass guide, not this graph.

The barometer is altitude in metres since the board powered on, not height above the ground. It will drift in wind and in prop wash. Foam over the sensor is the usual fix. The line is a fill, so a slow climb is easy to see.

The rangefinder is distance in centimetres, and it appears only when the board reports one. It is not the barometer. One is a sensor looking at the ground. The other is air pressure since power-on.

Airspeed is an INAV graph, in metres per second. It stays hidden on Betaflight. Near 0 in still air is right. Blow gently into the pitot tube and the line should rise. INAV can also show temperature sensors, LM75 or DS18B20, with a label, an OSD symbol and alarms. The alarm scale runs from -55 to 125 °C. A firmware build without temperature sensors hides that card.

The rate buttons are 10, 20 and 50 Hz. The tab starts at 20. The footer says faster rates use more of the link, and 20 Hz suits Bluetooth. A USB link can take 50 Hz. If the graphs stutter on Bluetooth, drop to 10 or stay at 20. Changing the rate clears every trace, so do it before you start a test, not in the middle of one.

Pause stops new samples. The lines stay where they were, which is how you read a spike after it happened. Resume continues. Pause does not change the sample rate.

Debug values are off until you turn them on. Betaflight draws 8 debug channels. INAV draws 4. The numbers are whatever debug mode was chosen on the configuration tab, the same names as set debug_mode in the CLI. None leaves them at zero. The debug graph is not a blackbox log. The log viewer is a separate page.

The demo answers these graphs with a simulated gyro, accelerometer and compass, including a little noise that grows when the motors are spinning. It is there so the traces have a shape before a board is connected. A real board replaces it.

Props off for the first look, the same as a motor test. A gyro that is quiet on the bench and wild when you spin a motor by hand is a mounting problem. A compass that is smooth in your hand and noisy on the craft is current, not a bad chip.

Chrome or Edge connects over USB or Bluetooth. Android adds Wi-Fi. iPhone uses Bluetooth or Wi-Fi and has no USB host. On Bluetooth, leave the rate at 20 Hz unless the link is clearly keeping up.

Calibration of the accelerometer is the Setup tab. Board alignment, the sensor on-off switches and the debug mode are the configuration tab. This page is only the live picture.