Function tilt_from_accel 

pub fn tilt_from_accel(ax: f64, ay: f64, az: f64) -> Tilt

Computes roll and pitch from a three-axis accelerometer reading.

At rest, gravity tells a three-axis accelerometer which way is down, which fixes the board’s tilt. This uses the standard formula (Freescale AN3461): roll is atan2(ay, az) and pitch is atan2(-ax, sqrt(ay^2 + az^2)), with atan2 placing each angle in the correct quadrant. The reading’s units do not matter (raw counts or g), because only the ratios between axes set the angle and any common scale cancels. It holds while the board is still or moving gently, since it assumes the only acceleration is gravity. Yaw (heading) cannot be found from an accelerometer alone; that needs a magnetometer.

Arguments

• ax - acceleration along the x (forward) axis.
• ay - acceleration along the y (right) axis.
• az - acceleration along the z (up) axis.

Returns

The Tilt in degrees.

Examples

use pamoja_kit::imu::tilt_from_accel;

// Board level, 1 g straight down on z: no tilt.
let level = tilt_from_accel(0.0, 0.0, 1.0);
assert!(level.roll.abs() < 1e-6 && level.pitch.abs() < 1e-6);

// Tipped fully onto its y axis: 90 degrees of roll.
let rolled = tilt_from_accel(0.0, 1.0, 0.0);
assert!((rolled.roll - 90.0).abs() < 1e-6);