Desktop Head Unit (DHU): how to mock sensors data

Question

Am trying to listen for sensor changes of Android auto through Desktop Head Unit with the following code

    val carHardwareManager = CarHardwareManager.create(carContext, HostDispatcher())
    val sensors = carHardwareManager.carSensors
    
    sensors.addAccelerometerListener(
    CarSensors.UPDATE_RATE_NORMAL, { }
    ) {
       Log.d(TAG, "onGetTemplate: Accelerometer statues = ${it.forces.status}")
       Log.d(TAG, "onGetTemplate: Accelerometer value = ${it.forces.value}")
      }

But am getting this error

java.lang.RuntimeException: androidx.car.app.HostException: Remote subscribeCarHardwareResult call failed
    at androidx.car.app.utils.RemoteUtils.lambda$dispatchCallFromHost$0(RemoteUtils.java:155)
    at androidx.car.app.utils.RemoteUtils$$ExternalSyntheticLambda1.run(Unknown Source:6)
    at androidx.car.app.utils.ThreadUtils.runOnMain(ThreadUtils.java:39)
    at androidx.car.app.utils.RemoteUtils.dispatchCallFromHost(RemoteUtils.java:147)
    at androidx.car.app.utils.RemoteUtils.lambda$dispatchCallFromHost$1(RemoteUtils.java:186)
    at androidx.car.app.utils.RemoteUtils$$ExternalSyntheticLambda2.run(Unknown Source:8)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:236)
    at android.app.ActivityThread.main(ActivityThread.java:8057)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:620)
    atcom.android.internal.os.ZygoteInit.main(ZygoteInit.java:1011)

As the documentation states, I enabled the sensors in the configuration file nad launched the DHU with it. But how to use their command. for example accel [x] [y] [z] where I use this command for example?

score 2 · Accepted Answer · answered Dec 22 '22 at 15:49

2

You type the command into the terminal window where you started the DHU.

For example, if you started the DHU on a Mac by typing

./desktop-head-unit -c configName.ini

you would also type the command into that same terminal after the DHU had started up and connected with the device - for example:

accel 1 1 1

and then the callback you've set on the listener should be invoked with the new data.

As far as the logs/crashing go, I think the issue might be that you're not properly setting an Executor as the second parameter for addAccelerometerListener. You can use carContext.mainExecutor as this param.

answered Dec 22 '22 at 15:49

Ben Sagmoe

440
2
9

I used `carContext.mainExecutor` but still getting the crashe. – Hussien Fahmy Dec 22 '22 at 17:35
The error points to the lone with `sensors.addAccelerometerListener` – Hussien Fahmy Dec 22 '22 at 17:38
1

Ahh, sorry I was focusing on the second half of the code. I'm pretty sure the issue is really in your first line of code where you're creating a `CarHardwareManager` using a new `HostDispatcher` instead of just getting the `CarHardwareManager` from the `carContext`. You should use something like `val carSensors = carContext.getCarService(CarHardwareManager::class.java).carSensors` instead of the first two lines in your snippet. – Ben Sagmoe Dec 27 '22 at 15:16

Desktop Head Unit (DHU): how to mock sensors data

1 Answers1