Android Open Source - RCCarController Direct Control Activity

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From Project

Back to project page RCCarController.

License

The source code is released under:

MIT License

Java Source Code

package zvikabh.rccarreceiver;
/*from w w w .  j av  a2 s .c o  m*/
import java.io.IOException;
import java.util.List;

import com.hoho.android.usbserial.driver.UsbSerialDriver;
import com.hoho.android.usbserial.driver.UsbSerialPort;
import com.hoho.android.usbserial.driver.UsbSerialProber;

import zvikabh.views.speedcontroller.SpeedControllerView;
import android.support.v7.app.ActionBarActivity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class DirectControlActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_direct_control);
    
        mViewSpeedController = (SpeedControllerView) findViewById(R.id.speedControllerView);
        mViewSpeedController.setThrottleChangedListener(new ThrottleChangeListener());

        IntentFilter filter = new IntentFilter();
        filter.addAction(RCCarReceiverService.ACTION_REQUEST_USB_PERMISSION);
        registerReceiver(mBroadcastReceiver, filter);

        findDevice();
    }

    @Override
    protected void onDestroy() {
        if (mUsbSerialPort != null) {
            try {
                mUsbSerialPort.close();
            } catch (IOException e) {
                Log.e(TAG, "Exception while closing port: " + e);
            }
        }
        
        mUsbSerialPort = null;
        
        unregisterReceiver(mBroadcastReceiver);
        
        super.onDestroy();
    }

    /**
     * Finds the Arduino USB device and asks the user for permission to use it.
     */
    private boolean findDevice() {
        UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
        List<UsbSerialDriver> availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(usbManager);
        
        // Find the Arduino device.
        for (UsbSerialDriver driver : availableDrivers) {
            UsbDevice device = driver.getDevice();
            int vendorId = device.getVendorId();
            int productId = device.getProductId();
            if ((vendorId == RCCarReceiverService.ARDUINO_USB_VENDOR_ID && 
                    productId == RCCarReceiverService.ARDUINO_UNO_USB_PRODUCT_ID) ||
                (vendorId == RCCarReceiverService.ARDUINO_CLONE_VENDOR_ID && 
                    productId == RCCarReceiverService.ARDUINO_CLONE_PRODUCT_ID)) {
                Log.d(TAG, "Found Arduino device!");
                
                mUsbSerialDriver = driver;
                
                // Request user's permission to access the device.
                // Processing continues in mBroadcastReceiver after user grants permission.
                PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, new Intent(RCCarReceiverService.ACTION_REQUEST_USB_PERMISSION), 0);
                usbManager.requestPermission(device, pendingIntent);
                return true;
            }
        }
        
        Log.e(TAG, "No Arduino devices found");
        Toast.makeText(this, "No Arduino devices found", Toast.LENGTH_LONG).show();
        return false;

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.direct_control, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
    

    /**
     * Class for handling notifications of user throttle changes.
     */
    private class ThrottleChangeListener implements SpeedControllerView.ThrottleChangedListener {

        @Override
        public void throttleChanged(float x, float y) {
            if (mUsbSerialPort == null) {
                Log.w(TAG, "Cannot update Arduino - connection to Arduino was unsuccessful.");
                return;
            }

            // Maximum power to deliver to each motor, on a scale of [0,1].
            final double maxPower = Math.min(1, Math.sqrt(x*x + y*y));

            // Angle in which car should move:
            // -pi:   turn left
            // -pi/2: backward
            // 0:     turn right
            // pi/2:  forward
            // pi:    turn left
            final double angle = Math.atan2(-y, x);
            
            final double pi = Math.PI;
            
            // Fraction of max power to deliver to the left and right motors.
            // Each motor (separately) is in the range [-1,1].
            double leftPower, rightPower;
            if (angle < -pi/2) {
                // angle is in [-pi, -pi/2].
                leftPower = -1.0;
                rightPower = -(angle + pi*0.75) / (pi/4);
            } else if (angle < 0) {
                // angle is in [-pi/2, 0].
                leftPower = (angle + pi/4) / (pi/4);
                rightPower = -1.0;
            } else if (angle < pi/2) {
                // angle is in [0, pi/2].
                leftPower = 1.0;
                rightPower = (angle - pi/4) / (pi/4);
            } else {
                // angle is in [pi/2, pi].
                leftPower = -(angle - pi*0.75) / (pi/4);
                rightPower = 1.0;
            }
                        
            final short leftPowerLevel = (short) (400 * leftPower * maxPower);
            final short rightPowerLevel = (short) (400 * rightPower * maxPower);
            
            final byte[] data = new byte[] { 0x7F, 0x7F, (byte)0x80, (byte)0x80, 0x00, 0x00, 0x00, 0x00 };
            data[4] = (byte) (leftPowerLevel & 0xFF);
            data[5] = (byte) ((leftPowerLevel >> 8) & 0xFF);
            data[6] = (byte) (rightPowerLevel & 0xFF);
            data[7] = (byte) ((rightPowerLevel >> 8) & 0xFF);
            
            try {
                mUsbSerialPort.write(data, 500);
            } catch (IOException e) {
                Log.w(TAG, "Failed to write to USB serial port: " + e.toString());
            }
        }
        
    }
    

    private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (action.equals(RCCarReceiverService.ACTION_REQUEST_USB_PERMISSION)) {
                if (!intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                    Log.e(TAG, "User did not grant permission to use the device.");
                    return;
                }
                openUsbSerialPort();
            }
        }
        
        /**
         * Completes the setup of the connection to the Arduino device,
         * after the user has granted permission to access it.
         * At this point, mUsbSerialDriver is set to the Arduino device.
         * Upon successful completion, mUsbSerialPort will point to the (opened) port.
         * Upon failure, mUsbSerialPort will be null.
         * @return true iff success
         */
        private boolean openUsbSerialPort() {
            UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
            UsbDeviceConnection connection = usbManager.openDevice(mUsbSerialDriver.getDevice());
            if (connection == null) {
                // Strange - we were supposed to have already gotten permission.
                Log.e(TAG, "No permission to access device");
                Toast.makeText(DirectControlActivity.this, "No permission to access device", Toast.LENGTH_LONG).show();
                mUsbSerialPort = null;
                return false;
            }
            
            List<UsbSerialPort> ports = mUsbSerialDriver.getPorts();
            if (ports.size() == 0) {
                Log.e(TAG, "Device has 0 ports");
                Toast.makeText(DirectControlActivity.this, "Device has 0 ports", Toast.LENGTH_LONG).show();
                mUsbSerialPort = null;
                return false;
            }
            
            mUsbSerialPort = ports.get(0);
            
            try {
                mUsbSerialPort.open(connection);
                mUsbSerialPort.setParameters(19200, UsbSerialPort.DATABITS_8, 
                        UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE);
            } catch (IOException e) {
                mUsbSerialPort = null;
                Log.e(TAG, "Could not open port");
                Toast.makeText(DirectControlActivity.this, "Could not open port", Toast.LENGTH_LONG).show();
                return false;
            }
            
            return true;
        }
        
    };
    
    private volatile UsbSerialPort mUsbSerialPort;
    private volatile UsbSerialDriver mUsbSerialDriver;
    
    private static final String TAG = "DirectControlActivity";
    
    private SpeedControllerView mViewSpeedController;

}

Java Source Code List

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