Android and Arduino hello world tutorial: Null point exception error

Hi,
I have tried the Hello world tutorial to blink the LED using UDOO QUAD , the link is below
http://www.udoo.org/tutorial/android-arduino-udoo-simple-hello-world-tutorial/
The app shows a null pointer exception during runtime, points to the lines below

if (buttonLED.isChecked()) {
mAdkManager.writeSerial("1");
} else {
mAdkManager.writeSerial("0");
}

After uploading to UDOO, the app stops working when the toggle buton is clicked, and also the Arduino shows the message "No installed apps work with this USB accessory" when the OTG connection is disabled while trying to reconnect with arduino's SAM 3X8E.

How can I solve this issue?

Mariam

 

check the log/java backtrace
it tells the problem

if it points to if (buttonLED.isChecked()) {
it must be buttonLED is null

 

the error points to the lines in bold , mAdkManager.writeSerial("1");

Check my new post, in ADKToolkit latest version uses write function instead of writeSerial and the following is the error log

FATAL EXCEPTION: main
Process: com.cocosystemsolutions.www.myled, PID: 1633
java.lang.NullPointerException
at me.palazzetti.adktoolkit.AdkManager.write(AdkManager.java:125)
at me.palazzetti.adktoolkit.AdkManager.write(AdkManager.java:119)
at com.cocosystemsolutions.www.myled.MainActivity$1.onClick(MainActivity.java:53)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)

 

The NullReferenceException is designed as a valid runtime condition that can be thrown and caught in normal program flow. It indicates that you are trying to access member fields, or function types, on an object reference that points to null. That means the reference to an Object which is not initialized.

Johnson