core-motion

Name: core-motion
Author: dpearson2699

915stars45forks

How to install core-motion?

dpearson2699/swift-ios-skills/core-motion

$npx -y skills add dpearson2699/swift-ios-skills --skill core-motion

Installs into the current project.

Summary

Access Core Motion accelerometer, gyroscope, magnetometer, device-motion, pedometer, activity-recognition, altitude, headphone motion, batched high-frequency workout motion, and water-submersion/depth data. Use when reading device sensors, counting steps, detecting walking/runnin

Files · 1

View on GitHub

SKILL.md

1	# CoreMotion
2
3	Read device motion, pedometer/activity, altitude, headphone, batched-workout,
4	and submersion sensors with Core Motion. Scope: Swift 6.3, iOS 26+.
5
6	## Contents
7
8	- [Setup](#setup)
9	- [CMMotionManager: Sensor Data](#cmmotionmanager-sensor-data)
10	- [Processed Device Motion](#processed-device-motion)
11	- [CMPedometer: Step and Distance Data](#cmpedometer-step-and-distance-data)
12	- [CMMotionActivityManager: Activity Recognition](#cmmotionactivitymanager-activity-recognition)
13	- [CMAltimeter: Altitude Data](#cmaltimeter-altitude-data)
14	- [Update Intervals and Battery](#update-intervals-and-battery)
15	- [Common Mistakes](#common-mistakes)
16	- [Review Checklist](#review-checklist)
17	- [References](#references)
18
19	## Setup
20
21	### Info.plist
22
23	Add `NSMotionUsageDescription` to Info.plist with a user-facing string explaining
24	why your app needs motion data. Without this key, the app crashes on first access.
25
26	```xml
27	<key>NSMotionUsageDescription</key>
28	<string>This app uses motion data to track your activity.</string>
29	```
30
31	### Authorization
32
33	Use the matching manager's `authorizationStatus()` or `authorizationStatus`
34	property when an API exposes one (`CMPedometer`, `CMMotionActivityManager`,
35	`CMAltimeter`, headphone motion, batched sensors, and submersion). Raw
36	`CMMotionManager` accelerometer/gyro/device-motion streams have no explicit
37	authorization request API; still ship the usage string and handle errors from
38	start/update callbacks.
39
40	```swift
41	import CoreMotion
42
43	let status = CMMotionActivityManager.authorizationStatus()
44	switch status {
45	case .notDetermined:
46	// Will prompt on first use
47	break
48	case .authorized:
49	break
50	case .restricted, .denied:
51	// Direct user to Settings
52	break
53	@unknown default:
54	break
55	}
56	```
57
58	## CMMotionManager: Sensor Data
59
60	Create exactly one `CMMotionManager` per app. Multiple instances degrade
61	sensor update rates.
62
63	```swift
64	import CoreMotion
65
66	let motionManager = CMMotionManager()
67	```
68
69	### Accelerometer Updates
70
71	```swift
72	guard motionManager.isAccelerometerAvailable else { return }
73
74	motionManager.accelerometerUpdateInterval = 1.0 / 60.0 // 60 Hz
75
76	motionManager.startAccelerometerUpdates(to: .main) { data, error in
77	guard let acceleration = data?.acceleration else { return }
78	print("x: \(acceleration.x), y: \(acceleration.y), z: \(acceleration.z)")
79	}
80
81	// When done:
82	motionManager.stopAccelerometerUpdates()
83	```
84
85	### Gyroscope Updates
86
87	```swift
88	guard motionManager.isGyroAvailable else { return }
89
90	motionManager.gyroUpdateInterval = 1.0 / 60.0
91
92	motionManager.startGyroUpdates(to: .main) { data, error in
93	guard let rotationRate = data?.rotationRate else { return }
94	print("x: \(rotationRate.x), y: \(rotationRate.y), z: \(rotationRate.z)")
95	}
96
97	motionManager.stopGyroUpdates()
98	```
99
100	### Polling Pattern (Games)
101
102	For games, start updates without a handler and poll the latest sample each frame:
103
104	```swift
105	motionManager.startAccelerometerUpdates()
106
107	// In your game loop / display link:
108	if let data = motionManager.accelerometerData {
109	let tilt = data.acceleration.x
110	// Move player based on tilt
111	}
112	```
113
114	## Processed Device Motion
115
116	Device motion fuses accelerometer, gyroscope, and magnetometer into a single
117	`CMDeviceMotion` object with attitude, user acceleration (gravity removed),
118	rotation rate, and calibrated magnetic field.
119
120	When giving device-motion guidance, show the runtime frame check in the snippet
121	instead of hard-coding a corrected, magnetic-north, or true-north frame. Fall
122	back to `.xArbitraryZVertical` when the preferred frame is unavailable.
123
124	```swift
125	guard motionManager.isDeviceMotionAvailable else { return }
126
127	let availableFrames = CMMotionManager.availableAttitudeReferenceFrames()
128	let frame: CMAttitudeReferenceFrame = availableFrames.contains(.xArbitraryCorrectedZVertical)
129	? .xArbitraryCorrectedZVertical
130	: .xArbitraryZVertical
131
132	motionManager.deviceMotionUpdateInterval = 1.0 / 60.0
133
134	motionManager.startDeviceMotionUpdates(
135	using: frame,
136	to: .main
137	) { motion, error in
138	guard let motion else { return }
139
140	let attitude = motion.attitude // roll, pitch, yaw
141	let userAccel = motion.userAcceleration
142	let gravity = motion.gravity
143	let heading = motion.heading // degrees relative to the current frame
144
145	print("Pitch: \(attitude.pitch), Roll: \(attitude.roll)")
146	}
147
148	motionManager.stopDeviceMotionUpdates()
149	```
150
151	### Attitude Reference Frames
152
153	For simple tilt controls, use `.xArbitraryZVertical` or
154	`.xArbitraryCorrectedZVertical`; they avoid magnetometer/location dependencies.
155	Before request

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Type

core-motion

915stars45forks

View on GitHub

How to install core-motion?

dpearson2699/swift-ios-skills/core-motion

$npx -y skills add dpearson2699/swift-ios-skills --skill core-motion

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# CoreMotion
2
3	Read device motion, pedometer/activity, altitude, headphone, batched-workout,
4	and submersion sensors with Core Motion. Scope: Swift 6.3, iOS 26+.
5
6	## Contents
7
8	- [Setup](#setup)
9	- [CMMotionManager: Sensor Data](#cmmotionmanager-sensor-data)
10	- [Processed Device Motion](#processed-device-motion)
11	- [CMPedometer: Step and Distance Data](#cmpedometer-step-and-distance-data)
12	- [CMMotionActivityManager: Activity Recognition](#cmmotionactivitymanager-activity-recognition)
13	- [CMAltimeter: Altitude Data](#cmaltimeter-altitude-data)
14	- [Update Intervals and Battery](#update-intervals-and-battery)
15	- [Common Mistakes](#common-mistakes)
16	- [Review Checklist](#review-checklist)
17	- [References](#references)
18
19	## Setup
20
21	### Info.plist
22
23	Add `NSMotionUsageDescription` to Info.plist with a user-facing string explaining
24	why your app needs motion data. Without this key, the app crashes on first access.
25
26	```xml
27	<key>NSMotionUsageDescription</key>
28	<string>This app uses motion data to track your activity.</string>
29	```
30
31	### Authorization
32
33	Use the matching manager's `authorizationStatus()` or `authorizationStatus`
34	property when an API exposes one (`CMPedometer`, `CMMotionActivityManager`,
35	`CMAltimeter`, headphone motion, batched sensors, and submersion). Raw
36	`CMMotionManager` accelerometer/gyro/device-motion streams have no explicit
37	authorization request API; still ship the usage string and handle errors from
38	start/update callbacks.
39
40	```swift
41	import CoreMotion
42
43	let status = CMMotionActivityManager.authorizationStatus()
44	switch status {
45	case .notDetermined:
46	// Will prompt on first use
47	break
48	case .authorized:
49	break
50	case .restricted, .denied:
51	// Direct user to Settings
52	break
53	@unknown default:
54	break
55	}
56	```
57
58	## CMMotionManager: Sensor Data
59
60	Create exactly one `CMMotionManager` per app. Multiple instances degrade
61	sensor update rates.
62
63	```swift
64	import CoreMotion
65
66	let motionManager = CMMotionManager()
67	```
68
69	### Accelerometer Updates
70
71	```swift
72	guard motionManager.isAccelerometerAvailable else { return }
73
74	motionManager.accelerometerUpdateInterval = 1.0 / 60.0 // 60 Hz
75
76	motionManager.startAccelerometerUpdates(to: .main) { data, error in
77	guard let acceleration = data?.acceleration else { return }
78	print("x: \(acceleration.x), y: \(acceleration.y), z: \(acceleration.z)")
79	}
80
81	// When done:
82	motionManager.stopAccelerometerUpdates()
83	```
84
85	### Gyroscope Updates
86
87	```swift
88	guard motionManager.isGyroAvailable else { return }
89
90	motionManager.gyroUpdateInterval = 1.0 / 60.0
91
92	motionManager.startGyroUpdates(to: .main) { data, error in
93	guard let rotationRate = data?.rotationRate else { return }
94	print("x: \(rotationRate.x), y: \(rotationRate.y), z: \(rotationRate.z)")
95	}
96
97	motionManager.stopGyroUpdates()
98	```
99
100	### Polling Pattern (Games)
101
102	For games, start updates without a handler and poll the latest sample each frame:
103
104	```swift
105	motionManager.startAccelerometerUpdates()
106
107	// In your game loop / display link:
108	if let data = motionManager.accelerometerData {
109	let tilt = data.acceleration.x
110	// Move player based on tilt
111	}
112	```
113
114	## Processed Device Motion
115
116	Device motion fuses accelerometer, gyroscope, and magnetometer into a single
117	`CMDeviceMotion` object with attitude, user acceleration (gravity removed),
118	rotation rate, and calibrated magnetic field.
119
120	When giving device-motion guidance, show the runtime frame check in the snippet
121	instead of hard-coding a corrected, magnetic-north, or true-north frame. Fall
122	back to `.xArbitraryZVertical` when the preferred frame is unavailable.
123
124	```swift
125	guard motionManager.isDeviceMotionAvailable else { return }
126
127	let availableFrames = CMMotionManager.availableAttitudeReferenceFrames()
128	let frame: CMAttitudeReferenceFrame = availableFrames.contains(.xArbitraryCorrectedZVertical)
129	? .xArbitraryCorrectedZVertical
130	: .xArbitraryZVertical
131
132	motionManager.deviceMotionUpdateInterval = 1.0 / 60.0
133
134	motionManager.startDeviceMotionUpdates(
135	using: frame,
136	to: .main
137	) { motion, error in
138	guard let motion else { return }
139
140	let attitude = motion.attitude // roll, pitch, yaw
141	let userAccel = motion.userAcceleration
142	let gravity = motion.gravity
143	let heading = motion.heading // degrees relative to the current frame
144
145	print("Pitch: \(attitude.pitch), Roll: \(attitude.roll)")
146	}
147
148	motionManager.stopDeviceMotionUpdates()
149	```
150
151	### Attitude Reference Frames
152
153	For simple tilt controls, use `.xArbitraryZVertical` or
154	`.xArbitraryCorrectedZVertical`; they avoid magnetometer/location dependencies.
155	Before request

People who liked this also viewed

6 picks

Type