ios - Is there any way to access the accelerometer from the Apple Watch?

Question

It doesn't look like WatchKit released today has such API included.

Answer 1

Sensor Data information is now available in Watchkit for watchOS 2.0.

You could check this information in the following session which is total 30 minutes presentation.If you do not want to watch entire session, then you directly jump to the CoreMotion and HealthKit features which is in between 22-28 min:

WatchKit for watchOS 2.0 Session in WWDC 2015

Heart Rate Implementation

https://developer.apple.com/documentation/healthkit/hkworkout

Accelerometer Implementation

Here is the implementation of accelerometer in WatchKit Extension, Here is the reference:

import WatchKit
import Foundation
import CoreMotion

class InterfaceController: WKInterfaceController {
    
    
    @IBOutlet weak var labelX: WKInterfaceLabel!
    @IBOutlet weak var labelY: WKInterfaceLabel!
    @IBOutlet weak var labelZ: WKInterfaceLabel!
    let motionManager = CMMotionManager()
    
    
    override func awakeWithContext(context: AnyObject?) {
        super.awakeWithContext(context)
        
        motionManager.accelerometerUpdateInterval = 0.1
    }
    
    override func willActivate() {
        super.willActivate()
        
        if (motionManager.accelerometerAvailable == true) {
            let handler:CMAccelerometerHandler = {(data: CMAccelerometerData?, error: NSError?) -> Void in
                self.labelX.setText(String(format: "%.2f", data!.acceleration.x))
                self.labelY.setText(String(format: "%.2f", data!.acceleration.y))
                self.labelZ.setText(String(format: "%.2f", data!.acceleration.z))
            }
            motionManager.startAccelerometerUpdatesToQueue(NSOperationQueue.currentQueue()!, withHandler: handler)
        }
        else {
            self.labelX.setText("not available")
            self.labelY.setText("not available")
            self.labelZ.setText("not available")
        }
    }
    
    override func didDeactivate() {
        super.didDeactivate()
        
        motionManager.stopAccelerometerUpdates()
    }
}

Code for WatchOS 7.x

import WatchKit
import Foundation
import CoreMotion

class InterfaceController: WKInterfaceController {

    @IBOutlet weak var labelX: WKInterfaceLabel!
    @IBOutlet weak var labelY: WKInterfaceLabel!
    @IBOutlet weak var labelZ: WKInterfaceLabel!
    
    let motionManager = CMMotionManager()

    override func awake(withContext context: Any?) {
        super.awake(withContext: context)
        motionManager.accelerometerUpdateInterval = 0.1
    }

    override func willActivate() {
        super.willActivate()

        if (motionManager.isAccelerometerAvailable == true) {
            let handler:CMAccelerometerHandler = {data,error in
                self.labelX.setText(String(format: "%.2f", data!.acceleration.x))
                self.labelY.setText(String(format: "%.2f", data!.acceleration.y))
                self.labelZ.setText(String(format: "%.2f", data!.acceleration.z))
            }
            motionManager.startAccelerometerUpdates(to: OperationQueue.current!, withHandler: handler)
        }
        else {
            self.labelX.setText("not available")
            self.labelY.setText("not available")
            self.labelZ.setText("not available")
        }
    }

    override func didDeactivate() {
        super.didDeactivate()
        motionManager.stopAccelerometerUpdates()
    }
    
}