Class WeightMeasurement

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

A decoded Weight Measurement, characteristic 0x2A9D.

Wire format

Byte 0 is a flags field:

Bit Meaning
0 units: 0 = SI (kg), 1 = Imperial (lb)
1 timestamp present
2 user id present
3 BMI and height present

followed by a uint16 weight and the optional fields.

The resolution depends on the unit

The raw uint16 is scaled by 0.005 kg in SI mode and 0.01 lb in Imperial mode -- not the same multiplier, and not a simple unit conversion applied afterwards. Getting this wrong yields a weight that is wrong by a factor of about two, which is exactly close enough to look plausible. Height carries the same split: 0.001 m against 0.1 in.

Like all characteristics here this one is indicated, not notified.

  • Method Details

    • parse

      public static WeightMeasurement parse(byte[] value)
      Decodes a 0x2A9D value. Returns null for a malformed or truncated payload; never throws.

    • getWeightKg

      public double getWeightKg()
      The weight in kilograms, converted from pounds when the scale reported Imperial units.

    • isImperial

      public boolean isImperial()
      true when the scale transmitted Imperial units. Useful for matching the user's own display preference; the value returned by getWeightKg() is already normalized either way.

    • getHeightMeters

      public double getHeightMeters()
      The height in metres, or Double.NaN when absent.

    • getBmi

      public double getBmi()
      The body mass index the scale computed, or Double.NaN when absent.

    • hasBmiAndHeight

      public boolean hasBmiAndHeight()

      true when this reading carried BMI and height.

      Both, as the name says. The two fields are optional independently -- each carries its own 0xFFFF unavailable value and a scale that measured one but not the other sends both -- so testing only the BMI let a caller that gated on this go on to use a height of NaN.

    • getUserId

      public int getUserId()
      The scale's user-profile index, or -1 when absent. Family scales use it to attribute a reading.

    • getTimestampMillis

      public long getTimestampMillis()
      The scale's own timestamp in epoch millis, or -1 when absent.

    • 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