VEHICLE_SPEED_DISPLAY_UNITS
What it is
Speed units for display
Indicates type of units the car is using to display speed to user. Eg. m/s, km/h, or mph.
{@code VehicleAreaConfig.HasSupportedValueInfo.hasSupportedValuesList} for the global area ID (0) must be {@code true}.
{@code getSupportedValuesLists} for [VEHICLE_SPEED_DISPLAY_UNITS, areaId=0] must return a {@code SupportedValuesListResult} that contains non-null {@code supportedValuesList}, e.g. [METER_PER_SEC, MILES_PER_HOUR, KILOMETERS_PER_HOUR].
For backward compatibility, config array for this property must contain the same values as supported values at boot time. For example: configArray[0] = METER_PER_SEC configArray[1] = MILES_PER_HOUR configArray[2] = KILOMETERS_PER_HOUR
If updating VEHICLE_SPEED_DISPLAY_UNITS affects the values of other *_DISPLAY_UNITS properties, then their values must be updated and communicated to the AAOS framework as well.
This property is defined as VehiclePropertyAccess.READ_WRITE, but OEMs have the option to implement it as VehiclePropertyAccess.READ only.
How the ID is built
A property ID is a 32-bit value packing four fields. Reading 0x11400605 apart:
| Field | Mask | Value | Means |
|---|---|---|---|
| Group | 0xf0000000 | 0x10000000 | SYSTEM |
| Area | 0x0f000000 | 0x01000000 | GLOBAL |
| Type | 0x00ff0000 | 0x00400000 | INT32 |
| Ordinal | 0x0000ffff | 0x00000605 | 0x605 |
Reading it from an app
CarPropertyManager mgr = (CarPropertyManager)
car.getCarManager(Car.PROPERTY_SERVICE);
int value =
mgr.getIntProperty(VehiclePropertyIds.VEHICLE_SPEED_DISPLAY_UNITS, 0);This property can be read and written, though an OEM may implement it as read-only. It fires a callback whenever the value changes.