下面代码主要实现接口定义，实现从.so库文件接口函数在JAVA里面的声明；
package com.friendlyarm.AndroidSDK;

import android.util.Log;

public class HardwareControler

{

	/* Serial Port */

	static public native int openSerialPort( String devName, long baud, int dataBits, int stopBits );

	/* LED */

	static public native int setLedState( int ledID, int ledState );

    /* PWM */

	static public native int PWMPlay(int frequency);

	static public native int PWMStop();

    /* ADC */

	static public native int readADC();

	/* I2C */

	static public native int openI2CDevice();

	static public native int writeByteDataToI2C(int fd, int pos, byte byteData);

	static public native int readByteDataFromI2C(int fd, int pos);

	/* 通用接口 */

	static public native int write(int fd, byte[] data);

	static public native int read(int fd, byte[] buf, int len);

	static public native int select(int fd, int sec, int usec);

	static public native void close(int fd);

    static {

        try {

        	System.loadLibrary("friendlyarm-hardware");

        } catch (UnsatisfiedLinkError e) {

            Log.d("HardwareControler", "libfriendlyarm-hardware library not found!");

        }

    }

}

package com.friendlyarm.LEDDemo;

import android.app.Activity;

import android.os.Bundle;

import android.widget.TextView;

import android.view.View;

import android.widget.Button;

import android.view.View.OnClickListener;

import com.friendlyarm.AndroidSDK.HardwareControler;

public class LEDTestingActivity extends Activity implements OnClickListener {

	private Button btnLED1On;

	private Button btnLED1Off;

	private Button btnLED2On;

	private Button btnLED2Off;

	private Button btnLED3On;

	private Button btnLED3Off;

	private Button btnLED4On;

	private Button btnLED4Off; 

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

    	btnLED1On = (Button)findViewById(R.id.btnLED1On);

    	btnLED1Off = (Button)findViewById(R.id.btnLED1Off);

    	btnLED2On = (Button)findViewById(R.id.btnLED2On);

    	btnLED2Off = (Button)findViewById(R.id.btnLED2Off);

    	btnLED3On = (Button)findViewById(R.id.btnLED3On);

    	btnLED3Off = (Button)findViewById(R.id.btnLED3Off);

    	btnLED4On = (Button)findViewById(R.id.btnLED4On);

    	btnLED4Off = (Button)findViewById(R.id.btnLED4Off);

    	btnLED1On.setOnClickListener(this);

    	btnLED1Off.setOnClickListener(this);

    	btnLED2On.setOnClickListener(this);

    	btnLED2Off.setOnClickListener(this);

    	btnLED3On.setOnClickListener(this);

    	btnLED3Off.setOnClickListener(this);

    	btnLED4On.setOnClickListener(this);

    	btnLED4Off.setOnClickListener(this);

    }

	public void onClick(View v) {

		switch (v.getId()) {

		case R.id.btnLED1On:

			HardwareControler.setLedState(0,1);

			break;

		case R.id.btnLED1Off:

			HardwareControler.setLedState(0,0);

			break;

		case R.id.btnLED2On:

			HardwareControler.setLedState(1,1);

			break;

		case R.id.btnLED2Off:

			HardwareControler.setLedState(1,0);

			break;

		case R.id.btnLED3On:

			HardwareControler.setLedState(2,1);

			break;

		case R.id.btnLED3Off:

			HardwareControler.setLedState(2,0);

			break;

		case R.id.btnLED4On:

			HardwareControler.setLedState(3,1);

			break;

		case R.id.btnLED4Off:

			HardwareControler.setLedState(3,0);

			break;

		default:

			break;

		}

	}

}