Package edu.wpi.first.wpilibj

Class Timer

java.lang.Object
edu.wpi.first.wpilibj.Timer
public class Timer
extends Object
A timer class.

Note that if the user calls SimHooks.restartTiming(), they should also reset the timer so get() won't return a negative duration.

  • Constructor Summary

    Constructors 
    Constructor Description
    Timer()
    Timer constructor.

  • Method Summary

    Modifier and Type Method Description
    boolean advanceIfElapsed​(double seconds)
    Check if the period specified has passed and if it has, advance the start time by that period.
    static void delay​(double seconds)
    Pause the thread for a specified time.
    double get()
    Get the current time from the timer.
    static double getFPGATimestamp()
    Return the system clock time in seconds.
    static double getMatchTime()
    Return the approximate match time.
    boolean hasElapsed​(double seconds)
    Check if the period specified has passed.
    void reset()
    Reset the timer by setting the time to 0.
    void restart()
    Restart the timer by stopping the timer, if it is not already stopped, resetting the accumulated time, then starting the timer again.
    void start()
    Start the timer running.
    void stop()
    Stop the timer.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

  • Method Details

    • getFPGATimestamp

      public static double getFPGATimestamp()
      Return the system clock time in seconds. Return the time from the FPGA hardware clock in seconds since the FPGA started.
      Returns:
      Robot running time in seconds.

    • getMatchTime

      public static double getMatchTime()
      Return the approximate match time. The FMS does not send an official match time to the robots, but does send an approximate match time. The value will count down the time remaining in the current period (auto or teleop). Warning: This is not an official time (so it cannot be used to dispute ref calls or guarantee that a function will trigger before the match ends) The Practice Match function of the DS approximates the behavior seen on the field.
      Returns:
      Time remaining in current match period (auto or teleop) in seconds

    • delay

      public static void delay​(double seconds)
      Pause the thread for a specified time. Pause the execution of the thread for a specified period of time given in seconds. Motors will continue to run at their last assigned values, and sensors will continue to update. Only the task containing the wait will pause until the wait time is expired.
      Parameters:
      seconds - Length of time to pause

    • get

      public double get()
      Get the current time from the timer. If the clock is running it is derived from the current system clock the start time stored in the timer class. If the clock is not running, then return the time when it was last stopped.
      Returns:
      Current time value for this timer in seconds

    • reset

      public final void reset()
      Reset the timer by setting the time to 0.

      Make the timer startTime the current time so new requests will be relative now.

    • start

      public void start()
      Start the timer running. Just set the running flag to true indicating that all time requests should be relative to the system clock. Note that this method is a no-op if the timer is already running.

    • restart

      public void restart()
      Restart the timer by stopping the timer, if it is not already stopped, resetting the accumulated time, then starting the timer again. If you want an event to periodically reoccur at some time interval from the start time, consider using advanceIfElapsed() instead.

    • stop

      public void stop()
      Stop the timer. This computes the time as of now and clears the running flag, causing all subsequent time requests to be read from the accumulated time rather than looking at the system clock.

    • hasElapsed

      public boolean hasElapsed​(double seconds)
      Check if the period specified has passed.
      Parameters:
      seconds - The period to check.
      Returns:
      Whether the period has passed.

    • advanceIfElapsed

      public boolean advanceIfElapsed​(double seconds)
      Check if the period specified has passed and if it has, advance the start time by that period. This is useful to decide if it's time to do periodic work without drifting later by the time it took to get around to checking.
      Parameters:
      seconds - The period to check.
      Returns:
      Whether the period has passed.