Class CyclingPowerMeasurement

java.lang.Object
com.codename1.health.sensors.CyclingPowerMeasurement
public final class CyclingPowerMeasurement extends Object

A decoded Cycling Power Measurement, characteristic 0x2A63.

Wire format

Unlike most SIG characteristics the flags field here is a uint16, not a single byte, because the profile defines sixteen optional fields. It is followed immediately by the instantaneous power.

Instantaneous power is signed

The power field is sint16, and negative values are real: a power meter reports negative watts when the rider is back-pedalling or the drivetrain is driving the cranks on a descent. Reading it as unsigned turns a brief -5 W into 65531 W, which then poisons every average and maximum for the whole ride.

This parser exposes the common fields -- instantaneous power, accumulated energy, pedal balance, crank revolutions. The remaining optional fields are skipped in order so that the fields after them still decode correctly.

  • Method Details

    • parse

      public static CyclingPowerMeasurement parse(byte[] value)
      Decodes a 0x2A63 value. Returns null for a malformed or truncated payload; never throws.

    • getInstantaneousPowerWatts

      public int getInstantaneousPowerWatts()
      Instantaneous power in watts. May be negative -- see the class documentation.

    • getPedalPowerBalancePercent

      public double getPedalPowerBalancePercent()
      The share of power contributed by one pedal, as a percentage, or Double.NaN when absent. Which pedal it refers to depends on the reference bit; most meters report the left.

    • getWheelRevolutions

      public long getWheelRevolutions()
      Cumulative wheel revolutions since the meter powered on, or -1 when absent. Wraps at 2^32.

    • getLastWheelEventTime

      public int getLastWheelEventTime()
      The wheel-event timestamp in 1/2048-second units, or -1 when absent. Wraps roughly every 32 seconds.

    • getCrankRevolutions

      public int getCrankRevolutions()
      Cumulative crank revolutions, or -1 when absent. Wraps at 2^16.

    • getLastCrankEventTime

      public int getLastCrankEventTime()
      The crank-event timestamp in 1/1024-second units, or -1 when absent. Wraps roughly every 64 seconds.

    • getAccumulatedEnergyKilojoules

      public int getAccumulatedEnergyKilojoules()
      Total energy in kilojoules since the meter powered on, or -1 when absent.

    • hasCrankData

      public boolean hasCrankData()
      true when this notification carried crank data, from which cadence can be derived.

    • toString

      public String toString()
      Description copied from class: Object
      Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method. The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of: getClass().getName() + '@' + Integer.toHexString(hashCode())
      Overrides:
      toString in class Object