README
MotionKit — The missing iOS wrapper :notes:
Now you can grab the data from Accelerometer, Magnetometer, Gyroscope and Device Motion in a magical way, with just a Two or a few lines of code. Fully compatible with both Swift and Objective-C.
A nice and clean wrapper around the CoreMotion Framework written entirely in Swift. The Core Motion framework lets your application receive motion data from device hardware and process that data.
The data can be retrieved from Accelerometer, Gyroscope and Magnetometer.
You can also get the refined and processed gyroscope and accelerometer data from the deviceMotion
datatype itself instead of getting the raw values.
Articles accompanying MotionKit: Link1 — Link2 — Link3
How does it work
You can retrieve all the values either by a trailing closure or by a delegate method. Both the approaches are fully supported.
Note: All the provided methods are Asynchronous and operate in their own Queue so that your app could run smoothly and efficiently.
Initialise
First, initialise the MotionKit instance. Its a Must.
Swift
let motionKit = MotionKit()
Objective-C
MotionKit *motionKit = [[NSClassFromString(@"MotionKit") alloc] init];
Getting Accelerometer Values
You can get the accelerometer values using just a few lines of code.
Swift
motionKit.getAccelerometerValues(interval: 1.0){
(x, y, z) in
//Interval is in seconds. And now you have got the x, y and z values here
....
}
Objective-C
[motionKit getAccelerometerValuesWithInterval:1.0 values:^(double x, double y, double z) {
// your values here
}];
Getting Gyroscope Values
Gyroscope values could be retrieved by the following few lines of code.
Swift
motionKit.getGyroValues(interval: 1.0){
(x, y, z) in
//Your processing will go here
....
}
Objective-C
[motionKit getGyroValues:1.0 values:^(double x, double y, double z) {
// your values here
}];
Getting Magnetometer Values
Getting Magnetometer values is as easy as grabbing a cookie.
Swift
motionKit.getMagnetometerValues(interval: 1.0){
(x, y, z) in
//Do something with the retrieved values
....
}
Objective-C
[motionKit getMagnetometerValues:1.0 values:^(double x, double y, double z) {
// your values here
}];
Installation
Embedded frameworks require a minimum deployment target of iOS 8.
— Using CocoaPods
Just add this to your Podfile.
pod 'MotionKit'
Note that you have to use CocoaPods version 0.36, the pre-released version which supports swift. If you don't already have it, you can grab it with a single command.
[sudo] gem install cocoapods --pre
— Using Carthage
You can use Carthage to install MotionKit
by adding the following line to your Cartfile
.
github "MHaroonBaig/MotionKit"
— Manual Installation
Just copy the MotionKit.swift
file into your Xcode project folder, and you're ready to go.
CMDeviceMotion - as easy as pie
In case if you want to get the processed values of Accelerometer or Gyroscope, you can access the deviceMotion object directly to get those values, or, you can access the individual values from the standalone methods which work seamlessly with Trailing Closures and Delegates.
The deviceMotion object includes:
- Acceleration Data
- userAcceleration
- gravity
- Calibrated Magnetic Field
- magneticField
- Attitude and Rotation Rate
- attitude
- rotationRate
All of the values can be retrieved either by individual methods or by getting the deviceMotion object itself.
Getting the whole CMDeviceMotion Object
Swift
motionKit.getDeviceMotionObject(interval: 1.0){
(deviceMotion) -> () in
var accelerationX = deviceMotion.userAcceleration.x
var gravityX = deviceMotion.gravity.x
var rotationX = deviceMotion.rotationRate.x
var magneticFieldX = deviceMotion.magneticField.x
var attitideYaw = deviceMotion.attitude.yaw
....
}
Objective-C
[motionKit getDeviceMotionObjectWithInterval:1.0 values:^(CMDeviceMotion *deviceMotion) {
// Your values here
}];
Getting refined values of Acceleration
You can get the refined and processed userAccelaration through the Device Motion service by just a few lines of code, either by a Trailing Closure or through Delegation method.
Swift
motionKit.getAccelerationFromDeviceMotion(interval: 1.0){
(x, y, z) -> () in
// Grab the x, y and z values
....
}
Objective-C
[motionKit getAccelerationFromDeviceMotion:1.0 values:^(double x, double y, double z) {
// your values here
}];
Getting Gravitational Acceleration
Again, you can access it through the Device Motion service as well.
Swift
motionKit.getGravityAccelerationFromDeviceMotion(interval: 1.0) {
(x, y, z) -> () in
// x, y and z values are here
....
}
Objective-C
[motionKit getGravityAccelerationFromDeviceMotion:1.0 values:^(double x, double y, double z) {
// your values here
}];
Getting Magnetic Field around your device
Interesting, Get it in a magical way.
Swift
motionKit.getMagneticFieldFromDeviceMotion(interval: 1.0) {
(x, y, z, accuracy) -> () in
// Get the values with accuracy
....
}
Objective-C
[motionKit getMagneticFieldFromDeviceMotion:1.0 values:^(double x, double y, double z) {
// your values here
}];
Getting the Attitude metrics
Swift
motionKit.getAttitudeFromDeviceMotion(interval: 1.0) {
(attitude) -> () in
var roll = attitude.roll
var pitch = attitude.pitch
var yaw = attitude.yaw
var rotationMatrix = attitude.rotationMatrix
var quaternion = attitude.quaternion
....
}
Objective-C
[motionKit getAttitudeFromDeviceMotionWithInterval:1.0 values:^(CMAttitude *attitude) {
// Your values here
}];
Getting Rotation Rate of your device
Swift
motionKit.getRotationRateFromDeviceMotion(interval: 1.0) {
(x, y, z) -> () in
// There you go, grab the x, y and z values
....
}
Objective-C
[motionKit getRotationRateFromDeviceMotion:1.0 values:^(double x, double y, double z) {
// your values here
}];
Precautions
For performance issues, it is suggested that you should use only one instance of CMMotionManager throughout the app. Make sure to stop receiving updates from the sensors as soon as you get your work done. You can do this in MotionKit like this.
//Make sure to call the required function when you're done
motionKit.stopAccelerometerUpdates()
motionKit.stopGyroUpdates()
motionKit.stopDeviceMotionUpdates()
motionKit.stopmagnetometerUpdates()
Delegates
In case if you dont want to use the trailing closures, we've got you covered. MotionKit supports the following Delegate methods to retrieve the sensor values.
optional func retrieveAccelerometerValues (x: Double, y:Double, z:Double, absoluteValue: Double)
optional func retrieveGyroscopeValues (x: Double, y:Double, z:Double, absoluteValue: Double)
optional func retrieveDeviceMotionObject (deviceMotion: CMDeviceMotion)
optional func retrieveMagnetometerValues (x: Double, y:Double, z:Double, absoluteValue: Double)
optional func getAccelerationValFromDeviceMotion (x: Double, y:Double, z:Double)
optional func getGravityAccelerationValFromDeviceMotion (x: Double, y:Double, z:Double)
optional func getRotationRateFromDeviceMotion (x: Double, y:Double, z:Double)
optional func getMagneticFieldFromDeviceMotion (x: Double, y:Double, z:Double)
optional func getAttitudeFromDeviceMotion (attitude: CMAttitude)
To use the above delegate methods, you have to add the MotionKit delegate to your ViewController.
class ViewController: UIViewController, MotionKitDelegate {
...
}
And in the ViewDidLoad method, you simply have to add this.
override func viewDidLoad() {
super.viewDidLoad()
motionKit.delegate = self
......
}
Having that done, you'd probably want to implement a delegate method like this.
func retrieveAccelerometerValues (x: Double, y:Double, z:Double, absoluteValue: Double){
//Do whatever you want with the x, y and z values. The absolute value is calculated through vector mathematics
......
}
func retrieveGyroscopeValues (x: Double, y:Double, z:Double, absoluteValue: Double){
//Do whatever you want with the x, y and z values. The absolute value is calculated through vector mathematics
......
}
Getting just a single value at an instant
if you want to get just a single value of any of the available sensors at a given time, you could probably use some of the our handy methods provided in MotionKit.
Accelerometer
Swift
motionKit.getAccelerationAtCurrentInstant {
(x, y, z) -> () in
....
}
Objective-C
[motionKit getAccelerationAtCurrentInstant:1.0 values:^(double x, double y, double z) {
// your values here
}];
Gravitational Acceleration
Swift
motionKit.getAccelerationAtCurrentInstant {
(x, y, z) -> () in
....
}
Objective-C
[motionKit getAccelerationAtCurrentInstant:1.0 values:^(double x, double y, double z) {
// your values here
}];
Attitude
Swift
motionKit.getAttitudeAtCurrentInstant {
(x, y, z) -> () in
....
}
Objective-C
[motionKit getAttitudeAtCurrentInstant:1.0 values:^(double x, double y, double z) {
// your values here
}];
Magnetic Field
Swift
motionKit.getMageticFieldAtCurrentInstant {
(x, y, z) -> () in
....
}
Objective-C
[motionKit getMageticFieldAtCurrentInstant:1.0 values:^(double x, double y, double z) {
// your values here
}];
Gyroscope Values
Swift
motionKit.getGyroValuesAtCurrentInstant {
(x, y, z) -> () in
....
}
Objective-C
[motionKit getGyroValuesAtCurrentInstant:1.0 values:^(double x, double y, double z) {
// your values here
}];
Discussion
You can join our Reddit channel to discuss anything.
You can also open an issue here for any kind of feature set that you want. We would love to hear from you.
Don't forget to subscribe our Reddit channel, which is /r/MotionKit
Our StackOverflow tag is 'MotionKit'
Requirements
- iOS 7.0+
- Xcode 6.1
TODO
- [ ] Add More Methods
- [ ] Adding Background Functionality
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
*Note that all licence references and agreements mentioned in the MotionKit README section above
are relevant to that project's source code only.