diff --git a/ADSB_Encoder.py b/ADSB_Encoder.py
index 9c83746..c5c6cc8 100755
--- a/ADSB_Encoder.py
+++ b/ADSB_Encoder.py
@@ -1,250 +1,19 @@
 #!/usr/bin/env python
 #
 
-##########################################################################
+from encoder import *
+from location import *
+from conversions import *
+from parity import *
 
-# Copyright 2010, 2012 Nick Foster
-# 
-# This file is part of gr-air-modes
-# 
-# gr-air-modes is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3, or (at your option)
-# any later version.
-# 
-# gr-air-modes is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-# 
-# You should have received a copy of the GNU General Public License
-# along with gr-air-modes; see the file COPYING.  If not, write to
-# the Free Software Foundation, Inc., 51 Franklin Street,
-# Boston, MA 02110-1301, USA.
-# 
-
-import math
-
-def encode_alt_modes(alt, bit13):
-    mbit = False
-    qbit = True
-    encalt = (int(alt) + 1000) / 25
-
-    if bit13 is True:
-        tmp1 = (encalt & 0xfe0) << 2
-        tmp2 = (encalt & 0x010) << 1
-
-    else:
-        tmp1 = (encalt & 0xff8) << 1
-        tmp2 = 0
-
-    return (encalt & 0x0F) | tmp1 | tmp2 | (mbit << 6) | (qbit << 4)
-
-latz = 15
-
-def nz(ctype):
-	return 4 * latz - ctype
-
-def dlat(ctype, surface):
-	if surface == 1:
-		tmp = 90.0
-	else:
-		tmp = 360.0
-
-	nzcalc = nz(ctype)
-	if nzcalc == 0:
-		return tmp
-	else:
-		return tmp / nzcalc
-
-def nl(declat_in):
-	if abs(declat_in) >= 87.0:
-		return 1.0
-	return math.floor( (2.0*math.pi) * math.acos(1.0- (1.0-math.cos(math.pi/(2.0*latz))) / math.cos( (math.pi/180.0)*abs(declat_in) )**2 )**-1)
-
-def dlon(declat_in, ctype, surface):
-	if surface:
-		tmp = 90.0
-	else:
-		tmp = 360.0
-	nlcalc = max(nl(declat_in)-ctype, 1)
-	return tmp / nlcalc
-
-#encode CPR position
-def cpr_encode(lat, lon, ctype, surface):
-    if surface is True:
-        scalar = 2.**19
-    else:
-        scalar = 2.**17
-
-    #encode using 360 constant for segment size.
-    dlati = dlat(ctype, False)
-    yz = math.floor(scalar * ((lat % dlati)/dlati) + 0.5)
-    rlat = dlati * ((yz / scalar) + math.floor(lat / dlati))
-    
-    #encode using 360 constant for segment size.
-    dloni = dlon(lat, ctype, False)
-    xz = math.floor(scalar * ((lon % dloni)/dloni) + 0.5)
-    
-    yz = int(yz) & (2**17-1)
-    xz = int(xz) & (2**17-1)
-    
-    return (yz, xz) #lat, lon
-
-###############################################################
-
-# Copyright (C) 2015 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# the polynominal generattor code for CRC
-GENERATOR = "1111111111111010000001001"
-
-def hex2bin(hexstr):
-    """Convert a hexdecimal string to binary string, with zero fillings. """
-    scale = 16
-    num_of_bits = len(hexstr) * math.log(scale, 2)
-    binstr = bin(int(hexstr, scale))[2:].zfill(int(num_of_bits))
-    return binstr
-
-def bin2int(binstr):
-    """Convert a binary string to integer. """
-    return int(binstr, 2)
-
-def crc(msg, encode=False):
-    """Mode-S Cyclic Redundancy Check
-    Detect if bit error occurs in the Mode-S message
-    Args:
-        msg (string): 28 bytes hexadecimal message string
-        encode (bool): True to encode the date only and return the checksum
-    Returns:
-        string: message checksum, or partity bits (encoder)
-    """
-
-    msgbin = list(hex2bin(msg))
-
-    if encode:
-        msgbin[-24:] = ['0'] * 24
-
-    # loop all bits, except last 24 piraty bits
-    for i in range(len(msgbin)-24):
-        # if 1, perform modulo 2 multiplication,
-        if msgbin[i] == '1':
-            for j in range(len(GENERATOR)):
-                # modulo 2 multiplication = XOR
-                msgbin[i+j] = str((int(msgbin[i+j]) ^ int(GENERATOR[j])))
-
-    # last 24 bits
-    reminder = ''.join(msgbin[-24:])
-    return reminder
     
 ###############################################################
 
-'''
-   Copyright 2015 Wolfgang Nagele
 
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-'''
-def bin2dec(buf):
-  if 0 == len(buf): # Crap input
-    return -1
-  return int(buf, 2)
-
-# Ported from: http://www.radarspotters.eu/forum/index.php?topic=5617.msg41293#msg41293
-def get_parity(msg, extended):
-  msg_length = len(msg)
-  payload = msg[:msg_length - 24]
-  parity = msg[msg_length - 24:]
-
-  data = bin2dec(payload[0:32])
-  if extended:
-    data1 = bin2dec(payload[32:64])
-    data2 = bin2dec(payload[64:]) << 8
-
-  hex_id = bin2dec(parity) << 8
-
-  for i in range(0, len(payload)):
-    if ((data & 0x80000000) != 0):
-      data ^= 0xFFFA0480
-    data <<= 1
-
-    if extended:
-      if ((data1 & 0x80000000) != 0):
-        data |= 1
-      data1 <<= 1
-
-      if ((data2 & 0x80000000) != 0):
-        data1 = data1 | 1
-      data2 <<= 1
-
-  return data
-  #return (data ^ hex_id) >> 8
 
 ###############################################################
 
-"""
-Hamming and Manchester Encoding example
 
-Author: Joel Addison
-Date: March 2013
-
-Functions to do (7,4) hamming encoding and decoding, including error detection
-and correction.
-Manchester encoding and decoding is also included, and by default will use
-least bit ordering for the byte that is to be included in the array.
-"""
-
-def extract_bit(byte, pos):
-    """
-    Extract a bit from a given byte using MS ordering.
-    ie. B7 B6 B5 B4 B3 B2 B1 B0
-    """
-    return (byte >> pos) & 0x01
-
-def manchester_encode(byte):
-    """
-    Encode a byte using Manchester encoding. Returns an array of bits.
-    Adds two start bits (1, 1) and one stop bit (0) to the array.
-    """
-    # Add start bits (encoded 1, 1)
-    # manchester_encoded = [0, 1, 0, 1]
-    manchester_encoded = []
-
-    # Encode byte
-    for i in range(7, -1, -1):
-        if extract_bit(byte, i):
-            manchester_encoded.append(0)
-            manchester_encoded.append(1)
-        else:
-            manchester_encoded.append(1)
-            manchester_encoded.append(0)
-
-    # Add stop bit (encoded 0)
-    # manchester_encoded.append(1)
-    # manchester_encoded.append(0)
-
-    return manchester_encoded
 
 ###############################################################
 
diff --git a/conversions.py b/conversions.py
new file mode 100644
index 0000000..b5ca69f
--- /dev/null
+++ b/conversions.py
@@ -0,0 +1,59 @@
+###############################################################
+
+# Copyright (C) 2015 Junzi Sun (TU Delft)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# the polynominal generattor code for CRC
+import math
+
+GENERATOR = "1111111111111010000001001"
+
+def hex2bin(hexstr):
+    """Convert a hexdecimal string to binary string, with zero fillings. """
+    scale = 16
+    num_of_bits = len(hexstr) * math.log(scale, 2)
+    binstr = bin(int(hexstr, scale))[2:].zfill(int(num_of_bits))
+    return binstr
+
+def bin2int(binstr):
+    """Convert a binary string to integer. """
+    return int(binstr, 2)
+
+def crc(msg, encode=False):
+    """Mode-S Cyclic Redundancy Check
+    Detect if bit error occurs in the Mode-S message
+    Args:
+        msg (string): 28 bytes hexadecimal message string
+        encode (bool): True to encode the date only and return the checksum
+    Returns:
+        string: message checksum, or partity bits (encoder)
+    """
+
+    msgbin = list(hex2bin(msg))
+
+    if encode:
+        msgbin[-24:] = ['0'] * 24
+
+    # loop all bits, except last 24 piraty bits
+    for i in range(len(msgbin)-24):
+        # if 1, perform modulo 2 multiplication,
+        if msgbin[i] == '1':
+            for j in range(len(GENERATOR)):
+                # modulo 2 multiplication = XOR
+                msgbin[i+j] = str((int(msgbin[i+j]) ^ int(GENERATOR[j])))
+
+    # last 24 bits
+    reminder = ''.join(msgbin[-24:])
+    return reminder
diff --git a/encoder.py b/encoder.py
new file mode 100644
index 0000000..98af943
--- /dev/null
+++ b/encoder.py
@@ -0,0 +1,42 @@
+"""
+Hamming and Manchester Encoding example
+
+Author: Joel Addison
+Date: March 2013
+
+Functions to do (7,4) hamming encoding and decoding, including error detection
+and correction.
+Manchester encoding and decoding is also included, and by default will use
+least bit ordering for the byte that is to be included in the array.
+"""
+
+def extract_bit(byte, pos):
+    """
+    Extract a bit from a given byte using MS ordering.
+    ie. B7 B6 B5 B4 B3 B2 B1 B0
+    """
+    return (byte >> pos) & 0x01
+
+def manchester_encode(byte):
+    """
+    Encode a byte using Manchester encoding. Returns an array of bits.
+    Adds two start bits (1, 1) and one stop bit (0) to the array.
+    """
+    # Add start bits (encoded 1, 1)
+    # manchester_encoded = [0, 1, 0, 1]
+    manchester_encoded = []
+
+    # Encode byte
+    for i in range(7, -1, -1):
+        if extract_bit(byte, i):
+            manchester_encoded.append(0)
+            manchester_encoded.append(1)
+        else:
+            manchester_encoded.append(1)
+            manchester_encoded.append(0)
+
+    # Add stop bit (encoded 0)
+    # manchester_encoded.append(1)
+    # manchester_encoded.append(0)
+
+    return manchester_encoded
diff --git a/location.py b/location.py
new file mode 100644
index 0000000..b6068b7
--- /dev/null
+++ b/location.py
@@ -0,0 +1,89 @@
+##########################################################################
+
+# Copyright 2010, 2012 Nick Foster
+# 
+# This file is part of gr-air-modes
+# 
+# gr-air-modes is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+# 
+# gr-air-modes is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with gr-air-modes; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+
+import math
+
+def encode_alt_modes(alt, bit13):
+    mbit = False
+    qbit = True
+    encalt = (int(alt) + 1000) / 25
+
+    if bit13 is True:
+        tmp1 = (encalt & 0xfe0) << 2
+        tmp2 = (encalt & 0x010) << 1
+
+    else:
+        tmp1 = (encalt & 0xff8) << 1
+        tmp2 = 0
+
+    return (encalt & 0x0F) | tmp1 | tmp2 | (mbit << 6) | (qbit << 4)
+
+latz = 15
+
+def nz(ctype):
+	return 4 * latz - ctype
+
+def dlat(ctype, surface):
+	if surface == 1:
+		tmp = 90.0
+	else:
+		tmp = 360.0
+
+	nzcalc = nz(ctype)
+	if nzcalc == 0:
+		return tmp
+	else:
+		return tmp / nzcalc
+
+def nl(declat_in):
+	if abs(declat_in) >= 87.0:
+		return 1.0
+	return math.floor( (2.0*math.pi) * math.acos(1.0- (1.0-math.cos(math.pi/(2.0*latz))) / math.cos( (math.pi/180.0)*abs(declat_in) )**2 )**-1)
+
+def dlon(declat_in, ctype, surface):
+	if surface:
+		tmp = 90.0
+	else:
+		tmp = 360.0
+	nlcalc = max(nl(declat_in)-ctype, 1)
+	return tmp / nlcalc
+
+#encode CPR position
+def cpr_encode(lat, lon, ctype, surface):
+    if surface is True:
+        scalar = 2.**19
+    else:
+        scalar = 2.**17
+
+    #encode using 360 constant for segment size.
+    dlati = dlat(ctype, False)
+    yz = math.floor(scalar * ((lat % dlati)/dlati) + 0.5)
+    rlat = dlati * ((yz / scalar) + math.floor(lat / dlati))
+    
+    #encode using 360 constant for segment size.
+    dloni = dlon(lat, ctype, False)
+    xz = math.floor(scalar * ((lon % dloni)/dloni) + 0.5)
+    
+    yz = int(yz) & (2**17-1)
+    xz = int(xz) & (2**17-1)
+    
+    return (yz, xz) #lat, lon
diff --git a/parity.py b/parity.py
new file mode 100644
index 0000000..b7d1112
--- /dev/null
+++ b/parity.py
@@ -0,0 +1,49 @@
+'''
+   Copyright 2015 Wolfgang Nagele
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+'''
+def bin2dec(buf):
+  if 0 == len(buf): # Crap input
+    return -1
+  return int(buf, 2)
+
+# Ported from: http://www.radarspotters.eu/forum/index.php?topic=5617.msg41293#msg41293
+def get_parity(msg, extended):
+  msg_length = len(msg)
+  payload = msg[:msg_length - 24]
+  parity = msg[msg_length - 24:]
+
+  data = bin2dec(payload[0:32])
+  if extended:
+    data1 = bin2dec(payload[32:64])
+    data2 = bin2dec(payload[64:]) << 8
+
+  hex_id = bin2dec(parity) << 8
+
+  for i in range(0, len(payload)):
+    if ((data & 0x80000000) != 0):
+      data ^= 0xFFFA0480
+    data <<= 1
+
+    if extended:
+      if ((data1 & 0x80000000) != 0):
+        data |= 1
+      data1 <<= 1
+
+      if ((data2 & 0x80000000) != 0):
+        data1 = data1 | 1
+      data2 <<= 1
+
+  return data
+  #return (data ^ hex_id) >> 8