1. Using Thread in leJOS

2. Introduction to thread A thread is a thread of execution in a program The Java Virtual Machine allows an application to have multiple threads of execution running concurrently. MMN Lab.

3. Thread in leJOS When a Java program starts, there is a single thread running – the main thread Extra threads in leJOS: –Button and SensorPort start a listener thread if listeners are used –Each Motor has a regulator thread –The Bluetooth class starts a thread to talk to the separate Bluetooth chip –Each Timer object starts a timer thread MMN Lab.

4. Using the thread Two approaches: –Inherit from java.lang.Thread The simple approach (We focus on this one) –Implement the Runnable interface The flexible approach (need jeJOS 0.7+) The most important method for Thread is run() Use start() to run the thread MMN Lab.

5. Using the thread cont’d Sample: class using thread MMN Lab.

6. Using the thread cont’d Sample: the main function MMN Lab.

7. Lab5 Scenario –1. Use the sound sensor to wait for trigger –2. Then start 3 threads (including the main() thread) with the following functions: Thread 1: beep every 0.5 sec Thread 2: swing the arm by triggering the sound sensor Thread3: steer by triggering the ultrasonic sensor –3. Exit the program after pressing ESCAPE MMN Lab.

8. Lab5 Hint: –Add a delay time if your program skip step1 – When you encounter a java exception with thread, adding a delay time may be helpful MMN Lab.