ego: orientation: allow for a more generous definition of earth gravity

src/ego/orientation.rs

@@ -33,7 +33,7 @@ impl OrientationEstimator {
                     // Estimate down from stationary accel
                     let avg = self.accel_history.data().iter().sum::<Vector3<f32>>()
                         / (self.accel_history.data().len() as f32);
-                    if avg.norm() >= 9.764 && avg.norm() <= 9.834 {
+                    if avg.norm() >= 9.1 && avg.norm() <= 9.9 {
                         self.down = Some(Unit::new_normalize(-avg));
                         self.sensor_bias = avg;
                         info!("Found down={:?} bias={:?}", self.down, self.sensor_bias);