async function myCellPhoneMotion(){
  document.getElementById('mySpanExport').innerHTML = `Checking if using a cell phone!<br>`;
  document.getElementById('mySpanExport').innerHTML += `/Android/i.test(navigator.userAgent): ${/Android/i.test(navigator.userAgent)}<br>`;
  document.getElementById('mySpanExport').innerHTML += `/iPhone|iPod/i.test(navigator.userAgent): ${/iPhone|iPod/i.test(navigator.userAgent)}<br>`;
  document.getElementById('mySpanExport').innerHTML += `navigator.userAgent: ${navigator.userAgent}<br>`
   
  if (typeof DeviceMotionEvent.requestPermission === 'function') {
    try {
      const permissionState = await DeviceMotionEvent.requestPermission();
      if (permissionState === 'granted') {
        window.addEventListener('devicemotion', handleMotionEvent);
      //  myCellPhoneEvent = false
        myCellPhoneOnce = true
      }
    } catch (error) {
      console.log(error);
      document.getElementById('mySpanResults').innerHTML = `Error: ${error}`;
    }
  } else {  // if things are already setup then just add the event listener
    window.addEventListener('devicemotion', handleMotionEvent);
  }
}

function handleMotionEvent(event) {
if (myCellPhoneOnce){    
  const { accelerationIncludingGravity } = event;
  let { x, y, z } = accelerationIncludingGravity;
   
   if ( /Android/i.test(navigator.userAgent) ) {  // correct only if not on desktop setting. Android orientation is opposite apple
      x *= -1;
      y *= -1;
      z *= -1;
   }
   
  const formattedX = typeof x === 'number' ? x.toFixed(2) : 'NaN';
  const formattedY = typeof y === 'number' ? y.toFixed(2) : 'NaN';
  const formattedZ = typeof z === 'number' ? z.toFixed(2) : 'NaN';

 // document.getElementById('myDiv01').innerHTML = `iPhone x: ${formattedX}, y: ${formattedY}, z: ${formattedZ}`;
   // Start collecting data if startTime is null
   if (startTime === null) {
     startTime = performance.now();
   }
   
   // Calculate elapsed time in milliseconds
   const elapsedTime = performance.now() - startTime;
   
   // Collect accelerometer data for 500 ms
   if (elapsedTime < 410) {  // 500 ~ 30 samples, I want 25 samples
     accelerometerData.push([formattedX, formattedY, formattedZ]);
   }
   else if (elapsedTime > 1000 ){} // estentially do nothing if the event handler does not get erased         
   else {
      // put the data in the main textarea
      if (mySendFirstLine) { document.getElementById('myArea01').value = 'accelX,accelY,accelZ\r\n';  }   // prints first line for CSV saving
        document.getElementById('myArea01').value += accelerometerData.join('\r\n')  // puts linefeed at end of data
        myShowGraph() 
        myCellPhoneOnce = false  
        window.removeEventListener('devicemotion', handleMotionEvent); 
      }
   
   } 
}