Android Things - I2C2 已在使用中（代码 16）

Question

I am trying to connect ADS1015 ADC with my Pico Pro Maker. Unfortunately, I got folowing error:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.cililing.harvbox.thingsapp, PID: 1855
    java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:448)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
     Caused by: com.google.android.things.pio.PioException: android.os.ServiceSpecificException: I2C2 is already in use (code 16)
        at com.google.android.things.pio.I2cDeviceImpl.<init>(I2cDeviceImpl.java:43)
        at com.google.android.things.pio.PeripheralManager.openI2cDevice(PeripheralManager.java:246)
        at com.google.android.things.contrib.driver.adc.ads1xxx.Ads1xxx.<init>(Ads1xxx.java:200)
        at com.google.android.things.contrib.driver.adc.ads1xxx.Ads1xxx.<init>(Ads1xxx.java:187)
        at com.cililing.harvbox.thingsapp.thingscontroller.controllers.ADS1015ControllerImpl.<init>(ADS1015Controller.kt:12)
        at com.cililing.harvbox.thingsapp.ui.MainActivity$i2CController$2.invoke(MainActivity.kt:40)
        at com.cililing.harvbox.thingsapp.ui.MainActivity$i2CController$2.invoke(MainActivity.kt:33)
        at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
        at com.cililing.harvbox.thingsapp.ui.MainActivity.getI2CController(Unknown Source:25)
        at com.cililing.harvbox.thingsapp.ui.MainActivity.access$getI2CController$p(MainActivity.kt:33)
        at com.cililing.harvbox.thingsapp.ui.MainActivity$i2cLogger$1.run(MainActivity.kt:47)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
     Caused by: android.os.ServiceSpecificException: I2C2 is already in use (code 16)
        at android.os.Parcel.readException(Parcel.java:2027)
        at android.os.Parcel.readException(Parcel.java:1959)
        at com.google.android.things.pio.IPeripheralManagerClient$Stub$Proxy.OpenI2cDevice(IPeripheralManagerClient.java:1243)
        at com.google.android.things.pio.I2cDeviceImpl.<init>(I2cDeviceImpl.java:41)
        at com.google.android.things.pio.PeripheralManager.openI2cDevice(PeripheralManager.java:246) 
        at com.google.android.things.contrib.driver.adc.ads1xxx.Ads1xxx.<init>(Ads1xxx.java:200) 
        at com.google.android.things.contrib.driver.adc.ads1xxx.Ads1xxx.<init>(Ads1xxx.java:187) 
        at com.cililing.harvbox.thingsapp.thingscontroller.controllers.ADS1015ControllerImpl.<init>(ADS1015Controller.kt:12) 
        at com.cililing.harvbox.thingsapp.ui.MainActivity$i2CController$2.invoke(MainActivity.kt:40) 
        at com.cililing.harvbox.thingsapp.ui.MainActivity$i2CController$2.invoke(MainActivity.kt:33) 
        at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74) 
        at com.cililing.harvbox.thingsapp.ui.MainActivity.getI2CController(Unknown Source:25) 
        at com.cililing.harvbox.thingsapp.ui.MainActivity.access$getI2CController$p(MainActivity.kt:33) 
        at com.cililing.harvbox.thingsapp.ui.MainActivity$i2cLogger$1.run(MainActivity.kt:47) 
        at android.os.Handler.handleCallback(Handler.java:790) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:164) 
        at android.app.ActivityThread.main(ActivityThread.java:6494) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 

I am using following driver: https://github.com/androidthings/contrib-drivers/tree/master/adc

What I've already done:

• uninstall all apps
• reinstall whole AndroidThings
• I tired both, I2C1 and I2C2
• try to read value on new app (only example from library).

I have no idea what can I do more. I am pretty sure that device is connected properly (scl-scl, sda-sda, addr-gnd, a0-other_analog_output) to main board and error is actually kind of strange, as I am sure that none other app uses those pins.

code responsible for connecting with peripheral:

class ADS1015ControllerImpl(val i2cName: String,
                            val range: Int) : ADS1015Controller {

    private val instance: Ads1xxx = Ads1xxx(i2cName, Ads1xxx.Configuration.ADS1015)
    init {
        instance.inputRange = range
    }

    override fun read(channel: Int, logger: (Int) -> Unit) {
        logger.invoke(
                instance.readSingleEndedInput(channel)
        )
    }

    override fun release() {
        instance.close()
    }
}

Answer 1

The error message I2C2 is already in use (code 16) means you are trying to open more than one connection to the same I2C bus without closing the previous instance. The code to open the I2C connection lives within the Ads1xxx constructor. You must either manage a single instance of this class in your code, or be certain that you call close() on the current Ads1xxx before initializing another one.

Based on the stack trace, it also looks like this device is being initialized by a lazy load when the value it first accessed, so it's possible that this constructor is not getting invoked at the point you expected, causing things to come out of order.

Answer 2

In fact, the problem was a badly soldered plug. :)