[DeviceMotion] convert rotationRate to degrees (#7876)

* Use correct gravity

* convert rotationRate to degrees

* Fix rotation rate order on Android and in docs

* Make default update interval match iOS and web

* Correct ios rotation rate

* Correct device motion types

* fixed type conversion

docs/pages/versions/unversioned/sdk/devicemotion.md

@@ -47,13 +47,19 @@ Subscribe for updates to DeviceMotion.
   DeviceMotion update is available. When invoked, the listener is
   provided a single argument that is an object containing following fields:
 
+  - **interval (_number_)** -- Interval at which data is obtained from the native platform. Expressed in **milliseconds**.
+
   - **acceleration (_object_)** -- Device acceleration on the three axis as an object with x, y, z keys. Expressed in m/s<sup>2</sup>.
 
   - **accelerationIncludingGravity (_object_)** -- Device acceleration with the effect of gravity on the three axis as an object with x, y, z keys. Expressed in m/s<sup>2</sup>.
 
   - **rotation (_object_)** -- Device's orientation in space as an object with alpha, beta, gamma keys where alpha is for rotation around Z axis, beta for X axis rotation and gamma for Y axis rotation.
 
-  - **rotationRate (_object_)** -- Rotation rates of the device around each of its axes as an object with alpha, beta, gamma keys where alpha is around Z axis, beta for X axis and gamma for Y axis.
+  - **rotationRate (_object_)** -- Device's rate of rotation in space expressed in degrees per second (deg/s).
+
+    - **alpha (_number_)**: X axis rotation.
+    - **beta (_number_)**: Y axis rotation.
+    - **gamma (_number_)**: Z axis rotation.
 
   - **orientation (_number_)** -- Device orientation based on screen rotation. Value is on of `0` (portrait), `90` (right landscape), `180` (upside down), `-90` (left landscape).
 

packages/expo-sensors/CHANGELOG.md

@@ -4,6 +4,13 @@
 
 ### 🛠 Breaking changes
 
+- `DeviceMotion.addListener` emits events with `rotationRate` in degrees instead of radians on all platforms. ([#7876](https://github.com/expo/expo/pull/7876) by [@evanbacon](https://github.com/evanbacon))
+- `DeviceMotion.addListener` emits events with `rotationRate` in the form of alpha = x, beta = y, gamma = z on all platforms. ([#7876](https://github.com/expo/expo/pull/7876) by [@evanbacon](https://github.com/evanbacon))
+
 ### 🎉 New features
 
+- `DeviceMotion.addListener` emits events with `interval` property. ([#7876](https://github.com/expo/expo/pull/7876) by [@evanbacon](https://github.com/evanbacon))
+
 ### 🐛 Bug fixes
+
+- All sensors use more precise gravity `9.80665` instead of `9.8`. ([#7876](https://github.com/expo/expo/pull/7876) by [@evanbacon](https://github.com/evanbacon))

packages/expo-sensors/android/src/main/java/expo/modules/sensors/modules/DeviceMotionModule.java

@@ -16,6 +16,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.lang.Math;
 
 import org.unimodules.core.ExportedModule;
 import org.unimodules.core.ModuleRegistry;
@@ -33,7 +34,7 @@
 
 public class DeviceMotionModule extends ExportedModule implements SensorEventListener2 {
   private long mLastUpdate = 0;
-  private int mUpdateInterval = 100;
+  private float mUpdateInterval = 1.0f / 60.0f;
   private float[] mRotationMatrix = new float[9];
   private float[] mRotationResult = new float[3];
 
@@ -61,7 +62,8 @@ public String getName() {
   public Map<String, Object> getConstants() {
     return Collections.unmodifiableMap(new HashMap<String, Object>() {
       {
-        put("Gravity", 9.81);
+        // Gravity on the planet this module supports (currently just Earth) represented as m/s^2.
+        put("Gravity", 9.80665);
       }
     });
   }
@@ -231,27 +233,29 @@ private Bundle eventsToMap() {
     Bundle accelerationIncludingGravity = new Bundle();
     Bundle rotation = new Bundle();
     Bundle rotationRate = new Bundle();
-
+    double interval = 0;
     if (mAccelerationEvent != null) {
       acceleration.putDouble("x", mAccelerationEvent.values[0]);
       acceleration.putDouble("y", mAccelerationEvent.values[1]);
       acceleration.putDouble("z", mAccelerationEvent.values[2]);
       map.putBundle("acceleration", acceleration);
-
+      interval = mAccelerationEvent.timestamp;
     }
 
     if (mAccelerationIncludingGravityEvent != null && mGravityEvent != null) {
       accelerationIncludingGravity.putDouble("x", mAccelerationIncludingGravityEvent.values[0] - 2 * mGravityEvent.values[0]);
       accelerationIncludingGravity.putDouble("y", mAccelerationIncludingGravityEvent.values[1] - 2 * mGravityEvent.values[1]);
       accelerationIncludingGravity.putDouble("z", mAccelerationIncludingGravityEvent.values[2] - 2 * mGravityEvent.values[2]);
       map.putBundle("accelerationIncludingGravity", accelerationIncludingGravity);
+      interval = mAccelerationIncludingGravityEvent.timestamp;
     }
 
     if (mRotationRateEvent != null) {
-      rotationRate.putDouble("alpha", mRotationRateEvent.values[2]);
-      rotationRate.putDouble("beta", mRotationRateEvent.values[0]);
-      rotationRate.putDouble("gamma", mRotationRateEvent.values[1]);
+      rotationRate.putDouble("alpha", Math.toDegrees(mRotationRateEvent.values[0]));
+      rotationRate.putDouble("beta", Math.toDegrees(mRotationRateEvent.values[1]));
+      rotationRate.putDouble("gamma", Math.toDegrees(mRotationRateEvent.values[2]));
       map.putBundle("rotationRate", rotationRate);
+      interval = mRotationRateEvent.timestamp;
     }
 
     if (mRotationEvent != null) {
@@ -261,8 +265,10 @@ private Bundle eventsToMap() {
       rotation.putDouble("beta", -mRotationResult[1]);
       rotation.putDouble("gamma", mRotationResult[2]);
       map.putBundle("rotation", rotation);
+      interval = mRotationEvent.timestamp;
     }
 
+    map.putDouble("interval", interval);
     map.putInt("orientation", getOrientation());
 
     return map;

packages/expo-sensors/ios/EXSensors/EXSensorsManager.h

@@ -8,7 +8,8 @@
 #import <UMSensorsInterface/UMMagnetometerInterface.h>
 #import <UMSensorsInterface/UMMagnetometerUncalibratedInterface.h>
 
-static const float EXGravity = 9.81;
+// Gravity on the planet this module supports (currently just Earth) represented as m/s^2.
+static const float EXGravity = 9.80665;
 
 @interface EXSensorsManager : NSObject <UMInternalModule, UMAccelerometerInterface, UMBarometerInterface, UMDeviceMotionInterface, UMGyroscopeInterface, UMMagnetometerInterface, UMMagnetometerUncalibratedInterface>
 

packages/expo-sensors/ios/EXSensors/EXSensorsManager.m

@@ -291,9 +291,16 @@ - (float)getGravity
   return EXGravity;
 }
 
+- (float)radiansToDegrees:(double)radians
+{
+    return radians * 180 / M_PI;
+}
+
+// Match https://www.w3.org/TR/orientation-event/
 - (void)activateDeviceMotionUpdates
 {
-  [[self manager] setDeviceMotionUpdateInterval:0.1f];
+  float interval = 1.0f / 60.0f;
+  [[self manager] setDeviceMotionUpdateInterval:interval];
   __weak EXSensorsManager *weakSelf = self;
   [[self manager] startDeviceMotionUpdatesUsingReferenceFrame:CMAttitudeReferenceFrameXArbitraryCorrectedZVertical toQueue:[NSOperationQueue mainQueue] withHandler:^(CMDeviceMotion *data, NSError *error) {
     __strong EXSensorsManager *strongSelf = weakSelf;
@@ -320,12 +327,8 @@ - (void)activateDeviceMotionUpdates
         break;
     }
 
-    NSDictionary *result = @{
-                             @"acceleration": @{
-                                 @"x": @(data.userAcceleration.x * EXGravity),
-                                 @"y": @(data.userAcceleration.y * EXGravity),
-                                 @"z": @(data.userAcceleration.z * EXGravity)
-                                 },
+    NSMutableDictionary *result = [NSMutableDictionary dictionaryWithDictionary:@{
+                             @"acceleration": [NSNull null],
                              @"accelerationIncludingGravity": @{
                                  @"x": @((data.userAcceleration.x + data.gravity.x) * EXGravity),
                                  @"y": @((data.userAcceleration.y + data.gravity.y) * EXGravity),
@@ -336,14 +339,25 @@ - (void)activateDeviceMotionUpdates
                                  @"beta": @(data.attitude.pitch),
                                  @"gamma": @(data.attitude.roll),
                                  },
-                             @"rotationRate" :@{
-                                 @"alpha": @(data.rotationRate.z),
-                                 @"beta": @(data.rotationRate.y),
-                                 @"gamma": @(data.rotationRate.x)
-                                 },
-                             @"orientation": @(orientationDegrees)
-                             };
+                             @"rotationRate": [NSNull null],
+                             @"orientation": @(orientationDegrees),
+                             @"interval": @(interval),
+                             }];
 
+    if ([[strongSelf manager] isGyroAvailable]) {
+      result[@"acceleration"] = @{
+        @"x": @(data.userAcceleration.x * EXGravity),
+        @"y": @(data.userAcceleration.y * EXGravity),
+        @"z": @(data.userAcceleration.z * EXGravity)
+      };
+      // Rate of rotation of the hosting device in space expressed in degrees per second.
+      result[@"rotationRate"] = @{
+        @"alpha": @([strongSelf radiansToDegrees:data.rotationRate.x]),
+        @"beta": @([strongSelf radiansToDegrees:data.rotationRate.y]),
+        @"gamma": @([strongSelf radiansToDegrees:data.rotationRate.z])
+      };
+    }
+
     // DeviceMotionUpdates handle DeviceMotion data as well as magnetic field
     for (void (^handler)(NSDictionary *) in strongSelf.deviceMotionHandlers.allValues) {
       handler(result);

packages/expo-sensors/src/DeviceMotion.ts

@@ -2,7 +2,7 @@ import DeviceSensor from './DeviceSensor';
 import ExponentDeviceMotion from './ExponentDeviceMotion';
 
 export interface DeviceMotionMeasurement {
-  acceleration: {
+  acceleration: null | {
     x: number;
     y: number;
     z: number;
@@ -17,11 +17,27 @@ export interface DeviceMotionMeasurement {
     beta: number;
     gamma: number;
   };
-  rotationRate: {
+  /**
+   * Device's rate of rotation in space expressed in degrees per second (deg/s).
+   */
+  rotationRate: null | {
+    /**
+     * x axis rotation.
+     */
     alpha: number;
+    /**
+     * y axis rotation.
+     */
     beta: number;
+    /**
+     * z axis rotation.
+     */
     gamma: number;
   };
+  /**
+   * Interval at which data is obtained from the native platform. Expressed in **milliseconds**.
+   */
+  interval: number;
   orientation: number;
 }
 

packages/expo-sensors/src/ExponentDeviceMotion.web.ts

@@ -8,8 +8,11 @@ export default {
   get name(): string {
     return 'ExponentDeviceMotion';
   },
+  /**
+   * Gravity on the planet this module supports (currently just Earth) represented as m/s^2.
+   */
   get Gravity(): number {
-    return 9.81;
+    return 9.80665;
   },
   async isAvailableAsync(): Promise<boolean> {
     if (typeof DeviceMotionEvent === 'undefined') {

packages/jest-expo/src/preset/expoModules.js

@@ -829,7 +829,7 @@ module.exports = {
           systemFonts: { type: 'array' },
         },
         ExponentDeviceMotion: {
-          Gravity: { type: 'number', mock: 9.8100004196167 },
+          Gravity: { type: 'number', mock: 9.80665 },
           addListener: { type: 'function' },
           isAvailableAsync: { type: 'function' },
           removeListeners: { type: 'function' },