HVAC_TEMPERATURE_SET
What it is
HVAC target temperature set in Celsius.
The minFloatValue and maxFloatValue in VehicleAreaConfig must be defined.
The minFloatValue indicates the minimum temperature setting in Celsius. The maxFloatValue indicates the maximum temperature setting in Celsius.
If all the values between minFloatValue and maxFloatValue are not supported, the configArray can be used to list the valid temperature values that can be set. It also describes a lookup table to convert the temperature from Celsius to Fahrenheit and vice versa for this vehicle. The configArray must be defined if standard unit conversion is not supported on this vehicle.
The configArray is set as follows: configArray[0] = [the lower bound of the supported temperature in Celsius] * 10. configArray[1] = [the upper bound of the supported temperature in Celsius] * 10. configArray[2] = [the increment in Celsius] * 10. configArray[3] = [the lower bound of the supported temperature in Fahrenheit] * 10. configArray[4] = [the upper bound of the supported temperature in Fahrenheit] * 10. configArray[5] = [the increment in Fahrenheit] * 10.
The minFloatValue and maxFloatValue in VehicleAreaConfig must be equal to configArray[0] and configArray[1] respectively.
For example, if the vehicle supports temperature values as: [16.0, 16.5, 17.0 ,..., 28.0] in Celsius [60.5, 61.5, 62.5 ,..., 84.5] in Fahrenheit The configArray should be configArray = {160, 280, 5, 605, 845, 10}.
Ideally, the ratio of the Celsius increment to the Fahrenheit increment should be as close to the actual ratio of 1 degree Celsius to 1.8 degrees Fahrenheit.
There must be a one to one mapping of all Celsius values to Fahrenheit values defined by the configArray. The configArray will be used by clients to convert this property's temperature from Celsius to Fahrenheit. Also, it will let clients know what Celsius value to set the property to achieve their desired Fahreneheit value for the system. If the ECU does not have a one to one mapping of all Celsius values to Fahrenheit values, then the config array should only define the list of Celsius and Fahrenheit values that do have a one to one mapping.
For example, if the ECU supports Celsius values from 16 to 28 and Fahrenheit values from 60 to 85 both with an increment of 1, then one possible configArray would be {160, 280, 10, 600, 840, 20}. In this case, 85 would not be a supported temperature.
Any value set in between a valid value should be rounded to the closest valid value.
It is highly recommended that the OEM also implement the HVAC_TEMPERATURE_VALUE_SUGGESTION vehicle property because it provides applications a simple method for determining temperature values that can be set for this vehicle and for converting values between Celsius and Fahrenheit.
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 0x15600503 apart:
| Field | Mask | Value | Means |
|---|---|---|---|
| Group | 0xf0000000 | 0x10000000 | SYSTEM |
| Area | 0x0f000000 | 0x05000000 | SEAT |
| Type | 0x00ff0000 | 0x00600000 | FLOAT |
| Ordinal | 0x0000ffff | 0x00000503 | 0x503 |
Reading it from an app
CarPropertyManager mgr = (CarPropertyManager)
car.getCarManager(Car.PROPERTY_SERVICE);
float value =
mgr.getFloatProperty(VehiclePropertyIds.HVAC_TEMPERATURE_SET, areaId);This property can be read and written, though an OEM may implement it as read-only. It fires a callback whenever the value changes.