New Update library, example, upload and more

Proper error handling in the uploading python script
Much faster OTA example sketch with better results
New Update class that simplifies updating the firmware from any source
Updated Esp.updateSketch() to use the new class

tools/espota.py

@@ -17,48 +17,66 @@ def serve(remoteAddr, remotePort, filename):
   sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
   serverPort = 48266
   server_address = ('0.0.0.0', serverPort)
-  print('starting up on %s port %s' % server_address, file=sys.stderr)
-  sock.bind(server_address)
-  sock.listen(1)
+  print('Starting on %s:%s' % server_address, file=sys.stderr)
+  try:
+    sock.bind(server_address)
+    sock.listen(1)
+  except:
+    print('Socket Failed', file=sys.stderr)
+    return 1
  
-  sock2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-  remote_address = (remoteAddr, int(remotePort))
   content_size = os.path.getsize(filename)
-  print('upload size: %d' % content_size, file=sys.stderr)
+  print('Upload size: %d' % content_size, file=sys.stderr)
   message = '%d %d %d\n' % (0, serverPort, content_size)
  
-  while True:
-    # Wait for a connection
-    print('sending invitation', file=sys.stderr)
-    sent = sock2.sendto(message, remote_address)
+  # Wait for a connection
+  print('Sending invitation to:', remoteAddr, file=sys.stderr)
+  sock2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+  remote_address = (remoteAddr, int(remotePort))
+  sent = sock2.sendto(message, remote_address)
+  sock2.close()
+  
+  print('Waiting for device...\n', file=sys.stderr)
+  try:
     sock.settimeout(10)
-    print('waiting...', file=sys.stderr)
     connection, client_address = sock.accept()
     sock.settimeout(None)
     connection.settimeout(None)
+  except:
+    print('No response from device', file=sys.stderr)
+    sock.close()
+    return 1
+
+  try:
+    f = open(filename, "rb")
+    sys.stderr.write('Uploading')
+    sys.stderr.flush()
+    while True:
+      chunk = f.read(4096)
+      if not chunk: break
+      sys.stderr.write('.')
+      sys.stderr.flush()
+      connection.sendall(chunk)
+
+    print('\nWaiting for result...\n', file=sys.stderr)
     try:
-      print('connection from', client_address, file=sys.stderr)
- 
-      print('sending file %s\n' % filename, file=sys.stderr)
-      f = open(filename, "rb")
- 
-      while True:
-        chunk = f.read(4096)
-        if not chunk:
-          break
-          
-        sys.stderr.write('.')
-        sys.stderr.flush()
-        #print('sending %d' % len(chunk), file=sys.stderr)
-        connection.sendall(chunk)
- 
-      print('\ndone!', file=sys.stderr)
-      return 0
-        
-    finally:
+      connection.settimeout(60)
+      data = connection.recv(32)
+      print('Result: %s' % data, file=sys.stderr)
       connection.close()
       f.close()
-    return 1
+      return 0
+    except:
+      print('Result: No Answer!', file=sys.stderr)
+      connection.close()
+      f.close()
+      return 1
+    
+  finally:
+    connection.close()
+    f.close()
+  sock.close()
+  return 1
  
 def main(args):
   return serve(args[1], args[2], args[3])