Added a method to read data into a char buffer so that character-based (rather than byte-based) operations don't require a cast. As requested by Tom Igoe. Part of the fix to issue 439.

Author: amcewen

libraries/Ethernet/Udp.h

@@ -80,6 +80,9 @@ class UDP : public Stream {
   // Read up to len bytes from the current packet and place them into buffer
   // Returns the number of bytes read, or 0 if none are available
   virtual int read(unsigned char* buffer, size_t len);
+  // Read up to len characters from the current packet and place them into buffer
+  // Returns the number of characters read, or 0 if none are available
+  virtual int read(char* buffer, size_t len) { return read((unsigned char*)buffer, len); };
   // Return the next byte from the current packet without moving on to the next byte
   virtual int peek();
   virtual void flush();	// Finish reading the current packet

libraries/Ethernet/examples/UDPSendReceiveString/UDPSendReceiveString.pde

@@ -62,7 +62,7 @@ void loop() {
     Serial.println(Udp.remotePort());
 
     // read the packet into packetBufffer
-    Udp.read((byte*)packetBuffer,UDP_TX_PACKET_MAX_SIZE);
+    Udp.read(packetBuffer,UDP_TX_PACKET_MAX_SIZE);
     Serial.println("Contents:");
     Serial.println(packetBuffer);