TIRE_PRESSURE
What it is
Tire pressure
{@code HasSupportedValueInfo.hasMinSupportedValue} and {@code HasSupportedValueInfo.hasMaxSupportedValue} must be {@code true} for all areas.
{@code MinMaxSupportedValueResult.minSupportedValue} represents the lower bound of the recommended tire pressure for the tire at the specified area ID.
{@code MinMaxSupportedValueResult.maxSupportedValue} represents the upper bound of the recommended tire pressure for the tire at the specified area ID.
For example, if the recommended tire pressure of left_front tire is from 200.0 KILOPASCAL to 240.0 KILOPASCAL, {@code getMinMaxSupportedValue} for [propId=TIRE_PRESSURE, areaId=VehicleAreaWheel::LEFT_FRONT] must return a {@code MinMaxSupportedValueResult} with OK status, 200.0 as minSupportedValue, 240.0 as maxSupportedValue.
For backward compatibility, minFloatValue and maxFloatValue in {@code VehicleAreaConfig} must be set to the same as minSupportedValue and maxSupportedValue at boot time.
Each tire is identified by its areaConfig.areaId config.
For example: .areaConfigs = { VehicleAreaConfig { .areaId = VehicleAreaWheel::LEFT_FRONT, .minFloatValue = 200.0, .maxFloatValue = 240.0, } },
How the ID is built
A property ID is a 32-bit value packing four fields. Reading 0x17600309 apart:
| Field | Mask | Value | Means |
|---|---|---|---|
| Group | 0xf0000000 | 0x10000000 | SYSTEM |
| Area | 0x0f000000 | 0x07000000 | WHEEL |
| Type | 0x00ff0000 | 0x00600000 | FLOAT |
| Ordinal | 0x0000ffff | 0x00000309 | 0x309 |
Reading it from an app
CarPropertyManager mgr = (CarPropertyManager)
car.getCarManager(Car.PROPERTY_SERVICE);
mgr.registerCallback(callback,
VehiclePropertyIds.TIRE_PRESSURE,
CarPropertyManager.SENSOR_RATE_ONCHANGE);This property is read-only — writes are rejected. It changes continuously, so subscribe at a sample rate rather than polling.