Merge pull request #101 from jzaruba/feature/initial_baud_rate

Feature/initial baud rate

usbserial/src/main/java/com/felhr/usbserial/CDCSerialDevice.java

@@ -45,6 +45,8 @@ public class CDCSerialDevice extends UsbSerialDevice
     private UsbEndpoint outEndpoint;
     private UsbRequest requestIN;
 
+    private int initialBaudRate = 0;
+
     public CDCSerialDevice(UsbDevice device, UsbDeviceConnection connection)
     {
         this(device, connection, -1);
@@ -56,6 +58,16 @@ public class CDCSerialDevice extends UsbSerialDevice
         mInterface = device.getInterface(iface >= 0 ? iface : findFirstCDC(device));
     }
 
+    @Override
+    public void setInitialBaudRate(int initialBaudRate) {
+        this.initialBaudRate = initialBaudRate;
+    }
+
+    @Override
+    public int getInitialBaudRate() {
+        return initialBaudRate;
+    }
+
     @Override
     public boolean open()
     {
@@ -297,12 +309,29 @@ public class CDCSerialDevice extends UsbSerialDevice
         }
 
         // Default Setup
-        setControlCommand(CDC_SET_LINE_CODING, 0, CDC_DEFAULT_LINE_CODING);
+        setControlCommand(CDC_SET_LINE_CODING, 0, getInitialLineCoding());
         setControlCommand(CDC_SET_CONTROL_LINE_STATE, CDC_CONTROL_LINE_ON, null);
 
         return true;
     }
 
+    protected byte[] getInitialLineCoding() {
+        byte[] lineCoding;
+
+        int initialBaudRate = getInitialBaudRate();
+
+        if(initialBaudRate > 0) {
+            lineCoding = CDC_DEFAULT_LINE_CODING.clone();
+            for (int i = 0; i < 4; i++) {
+                lineCoding[i] = (byte) (initialBaudRate >> i*8 & 0xFF);
+            }
+        } else {
+            lineCoding = CDC_DEFAULT_LINE_CODING;
+        }
+
+        return lineCoding;
+    }
+
     private int setControlCommand(int request, int value, byte[] data)
     {
         int dataLength = 0;

usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java

@@ -112,6 +112,30 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
             serialBuffer.putWriteBuffer(buffer);
     }
 
+    /**
+     * <p>
+     *     Use this setter <strong>before</strong> calling {@link #open()} to override the default baud rate defined in this particular class.
+     * </p>
+     *
+     * <p>
+     *     This is a workaround for devices where calling {@link #setBaudRate(int)} has no effect once {@link #open()} has been called.
+     * </p>
+     *
+     * @param initialBaudRate baud rate to be used when initializing the serial connection
+     */
+    public void setInitialBaudRate(int initialBaudRate) {
+        // this class does not implement initialBaudRate
+    }
+
+    /**
+     * Classes that do not implement {@link #setInitialBaudRate(int)} should always return -1
+     *
+     * @return initial baud rate used when initializing the serial connection
+     */
+    public int getInitialBaudRate() {
+        return -1;
+    }
+
     @Override
     public int read(UsbReadCallback mCallback)
     {