iOS Core Motion Tutorial: Apps with Attitude

 

ios cmmotionmanager tutorial

First, we need to declare an instance of the CMMotionManager class, which Apple describes as the gateway to the motion services provided by iOS. It is good practice to share this instance throughout your application to maintain the highest level of performance. let motionManager = CMMotionManager(). Jul 26,  · The CMMotionManager is quite a large class because of how it manages all the aspects of Core Motion. In this tutorial we will just look at adding Core Motion to a test app, and then enabling the accelerometer updates, and then logging these to the console. Getting Started. To get started, download the beginning project. Jan 24,  · How to use Core Motion in iOS using Swift. Now create an instance of CMMotionManager object. Welcome to a place where words matter. On Medium, Author: Maksym Bilan.


CMMotionManager Tutorial - Part 1 - Accelerometer Data - DevFright


Over the coming weeks we are going ios cmmotionmanager tutorial delve in to Core Motion and look at what is available and what can be done with the data that your device provides, ios cmmotionmanager tutorial. Core Motion was introduced in iOS 4 and provided a way for your app to get data from the sensors on your phone. When Apple introduced the iPhone 5s, they changed the game a little by adding a motion coprocessor. This smaller processor has a single job of handling sensor data recorded by the various sensors on the device even while the device is asleep.

It quietly stores this information until the phone wakes up and an app requests the data. The processor requires a lot less power to run, and thus it keeps going 24 hours a day silently keeping this data. The sensors that Core Motion handles include the accelerometer, gyroscope, ios cmmotionmanager tutorial, as well as the ios cmmotionmanager tutorial, and barometer.

The types of data it manages are listed in the documentation on the Core Motion manager class. Briefly, the data includes accelerometer, which is the instantaneous acceleration over 3 dimensions. It also includes gyroscope data which includes the rotation around 3 axis. This last part of data is processed by what Apple calls its Core Motion sensor fusion algorithm. In this tutorial we will just look at adding Core Motion to a test app, and then enabling the accelerometer updates, and then logging these to the console.

To get started, download the beginning project. Line 7 we are checking that accelerometer data is available, and if so, we will begin our work on line 8. If modify the code above to ios cmmotionmanager tutorial the following, and then run the app on a device, you will see a lot of accelerometer updates logged to the console.

Line 2 is where we set the interval. This is how often we want to receive updates from the accelerometer. It can go quicker, but the fastest is determined by your hardware. Apple indicates that the updates can come in as quickly as Hz on all devices normally, and often quicker.

Apple suggests that if accuracy in delivery is important, it is best you analyse the provided time stamp for each sample. Line 3 we start the accelerometer updates. We also have a handler which is called each time updates are made, ios cmmotionmanager tutorial. Line 4 we just print the data which provides the x, y, and z, as well as a time stamp for each update. Go ahead and run the app and move the phone around to see how accelerometer data is represented in the console. To help you understand what the numbers mean, here is how you can interpret them.

If you hold the iPhone vertically with the screen facing towards you, X is the left to right axis. Y is the up and down axis, and Z is the 3rd dimension going ios cmmotionmanager tutorial you straight through ios cmmotionmanager tutorial screen to behind the phone. If your phone is laying on its back with the screen facing up, z will be around -1 or 1G. If you put the phone balancing on its left side, gravity is following the X axis.

Because the left side of the phone is on the desk, the reading of X will change to -1G. If you want to stop accelerometer updates, you can simply call the stopAccelerometerUpdates method on the motionManager object, ios cmmotionmanager tutorial.

If you do not want constant updates, you can call startAccelerometerUpdates without specifying the handler. To get accelerometer data when doing it this way, call ios cmmotionmanager tutorial accelerometerData method which returns a CMAccelerometerData which is a snapshot of the values at the moment you make a call to that method. Although this tutorial was brief, ios cmmotionmanager tutorial, we will move through the various classes and items available in Core Motion.

For some tutorials we may combine two together where that makes sense. There is no sample project to download with the completed code because of it being ios cmmotionmanager tutorial straight forward, but below is a copy of ViewController.

Getting Started To get started, download the beginning project. Step 1 is to import CoreMotion in to ViewController.

 

 

ios cmmotionmanager tutorial

 

class CMMotionManager: NSObject. Overview. Use a CMMotion Manager object to start the services that report movement detected by the device's onboard sensors. Use this object to receive four types of motion data: With the former method (new in iOS ), you can specify a reference frame to be used for the attitude estimates. First, we need to declare an instance of the CMMotionManager class, which Apple describes as the gateway to the motion services provided by iOS. It is good practice to share this instance throughout your application to maintain the highest level of performance. let motionManager = CMMotionManager(). Jan 24,  · How to use Core Motion in iOS using Swift. Now create an instance of CMMotionManager object. Welcome to a place where words matter. On Medium, Author: Maksym Bilan.