public void OnAcceleromterLaunchDetected() // IAcceleromterListener
{
if (countdown.ElapsedMilliseconds > 2000) // respect settle-down-timer of PageRun
{
if (listener != null)
{
status = "launchDetected";
stopwatch.Start();
Device.StartTimer(TimeSpan.FromMilliseconds(UPDATE_RATE_MS), OnTimer);
listener.OnAcceleromterLaunchDetected();
}
}
}
public void OnSensorChanged(SensorEvent e) // ISensorEventListener
{
if (e != null)
{
if ((e.Sensor.Type == SensorType.LinearAcceleration) || (e.Sensor.Type == SensorType.Accelerometer))
{
long launchTimeNow = stopwatch.ElapsedMilliseconds;
sensorX = e.Values[0];
sensorY = e.Values[1];
sensorZ = e.Values[2];
sensorTimestamp = e.Timestamp;
// e.Timestamp = nanoseconds since 01. januar 1970
// e.Timestamp / 1 000 000 000 = seconds
if (isFirstRun)
{
isFirstRun = false;
launchTimeLastUpdate = launchTimeNow;
launchTimeDetectedStart = 0;
sensorTimestampFirst = sensorTimestamp;
sensorAcceleration = 0;
sensorSpeed = 0;
DeviceDebugAndroid.LogToFileMethodStatic("first values received");
DeviceDebugAndroid.LogToFileMethodStatic("accelerometer info: " + GetInfo());
}
else
{
sensorXDelta = sensorX - sensorXLast;
sensorYDelta = sensorY - sensorYLast;
sensorZDelta = sensorZ - sensorZLast;
sensorTimestampDelta = sensorTimestampLast - sensorTimestamp;
var dt = sensorTimestampDelta / 1000000000.0f; // from nanoseconds to seconds
var sensorSpeedX = sensorXDelta * dt; // from acceleration to velocity (x component)
var sensorSpeedY = sensorYDelta * dt; // from acceleration to velocity (y component)
var sensorSpeedZ = sensorZDelta * dt; // from acceleration to velocity (z component)
// speed magnitude of all components
var magnitude = (float)Math.Sqrt(sensorSpeedX * sensorSpeedX + sensorSpeedY * sensorSpeedY + sensorSpeedZ * sensorSpeedZ);
// integrate the magnitude onto previous speed
// take the direction into account
if (sensorIsAccelerating)
{
sensorSpeed += magnitude;
}
else
{
sensorSpeed -= magnitude;
}
// acceleration calculation
var sensorXCompensated = sensorX - sensorAxisOffsetX;
var sensorYCompensated = sensorY - sensorAxisOffsetY;
var sensorZCompensated = sensorZ - sensorAxisOffsetZ;
// acceleration magnitude of all components
sensorAcceleration = (float)Math.Sqrt(sensorXCompensated * sensorXCompensated +
sensorYCompensated * sensorYCompensated +
sensorZCompensated * sensorZCompensated);
if (isRawDataLoggingEnabled)
{
DeviceDebugAndroid.LogToFileSensorStatic(GetTimeStamp(), sensorX, sensorY, sensorZ, sensorAcceleration);
}
long launchTimeDiff = launchTimeNow - launchTimeLastUpdate;
if (launchTimeDiff > launchTimeUpdateInterval)
{
launchTimeLastUpdate = launchTimeNow;
var launchForce = Math.Abs(sensorXDelta + sensorYDelta + sensorZDelta);
if (launchForce * 10 > launchForceDetectLimit)
{
if (launchTimeDetectedStart == 0)
{
launchTimeDetectedStart = launchTimeNow;
}
if (launchTimeNow - launchTimeDetectedStart > launchTimeDetectLimit)
{
if (listener != null)
{
listener.OnAcceleromterLaunchDetected();
launchTimeDetectedStart = 0;
}
}
}
}
}
sensorXLast = sensorX;
sensorYLast = sensorY;
sensorZLast = sensorZ;
sensorTimestampLast = sensorTimestamp;
if (listener != null)
{
listener.OnAcceleromterUpdate();
}
}
}
}
