--- a/maestro.py	Sun Jun 22 22:11:51 2014 +0200
+++ b/maestro.py	Mon Jun 23 01:31:25 2014 +0200
@@ -2,26 +2,59 @@
 A simple library for talking to the Pololu Maestro RC servo controllers.
 """
 
-class Error(Exception):
-    pass
-
-
-class InitError(Error):
-    """Failed to initialize Maestro."""
-
-
 class Maestro(object):
     def __init__(self, serial):
         self.serial = serial
 
-    def init(self):
-        if self._write([0xAA]) != [0xAA]:
-            raise InitError("Failed to initialize Maestro")
-
     def _write(self, values):
         self.serial.write(''.join(chr(v) for v in values))
-        return [ord(c) for c in self.serial.read()]
+
+    def _write_command(self, command):
+        self._write([int(command) | 128])
+
+    def _write_byte(self, byte):
+        self._write([int(byte) & 127])
+
+    def _write_word(self, word):
+        byte2, byte1 = divmod(int(word), 128)
+        self._write([byte1 & 127, byte2 & 127])
+
+    def _read(self, count):
+        return [ord(c) for c in self.serial.read(count)]
+
+    def _read_byte(self):
+        return self._read(1)[0]
+
+    def _read_word(self):
+        byte1, byte2 = self._read(2)
+        return byte1 + byte2 * 256
 
-    def move(self, servo, position):
-        byte2, byte1 = divmod(int(position * 4), 128)
-        self._write([0x84, servo & 127, byte1 & 127, byte2 & 127])
+    def init(self):
+        """Initializes the communication. Returns True on success."""
+        self._write_command(0xAA)
+        return self._read_byte() == 0xAA
+
+    def set_target(self, servo, target):
+        """Set the servo position, in 1/4 of milliseconds of pulse width."""
+        self._write_command(0x84)
+        self._write_word(target)
+
+    def set_speed(self, servo, speed):
+        """Set the servo speed limit."""
+        self._write_command(0x87)
+        self._write_word(speed)
+
+    def set_accel(self, servo, accel):
+        """Set the servo acceleration limit."""
+        self._write_command(0x89)
+        self._write_word(accel)
+
+    def get_target(self, servo):
+        """Read the current target position of a servo."""
+        self._write_command(0x90)
+        return self._read_word()
+
+    def get_moving_state(self):
+        """True if any servo is still moving, otherwise False."""
+        self._write_command(0x93)
+        return bool(self._read_byte())