diff --git a/ADSB_Encoder.py b/ADSB_Encoder.py
index 418f890..30b97b7 100755
--- a/ADSB_Encoder.py
+++ b/ADSB_Encoder.py
@@ -64,5 +64,6 @@ if __name__ == "__main__":
samples_array = hackrf.hackrf_raw_IQ_format(df17_array)
SamplesFile = open("Samples.iq8s", "wb") # TODO make this a function and take the file name. Also have the option to run dd on it.
+ # TODO make it empty the file first.
SamplesFile.write(samples_array)
os.system("dd if=Samples.iq8s of=Samples_256K.iq8s bs=4k seek=63") # TODO make this a flag, also make it take the file name
diff --git a/ModeS.py b/ModeS.py
index 813b9f1..21b612f 100644
--- a/ModeS.py
+++ b/ModeS.py
@@ -1,5 +1,5 @@
from location import *
-from conversions import *
+
class ModeS:
"""This class handles the ModeS ADSB manipulation
"""
@@ -38,7 +38,7 @@ class ModeS:
df17_str = "{0:02x}{1:02x}{2:02x}{3:02x}{4:02x}{5:02x}{6:02x}{7:02x}{8:02x}{9:02x}{10:02x}".format(*df17_even_bytes[0:11])
#print df17_str , "%X" % bin2int(crc(df17_str+"000000", encode=True)) , "%X" % get_parity(hex2bin(df17_str+"000000"), extended=True)
- df17_crc = bin2int(crc(df17_str+"000000", encode=True))
+ df17_crc = self.bin2int(self.modes_crc(df17_str+"000000", encode=True))
df17_even_bytes.append((df17_crc>>16) & 0xff)
df17_even_bytes.append((df17_crc>> 8) & 0xff)
@@ -60,10 +60,72 @@ class ModeS:
df17_odd_bytes.append((oddenclon ) & 0xff)
df17_str = "{0:02x}{1:02x}{2:02x}{3:02x}{4:02x}{5:02x}{6:02x}{7:02x}{8:02x}{9:02x}{10:02x}".format(*df17_odd_bytes[0:11])
- df17_crc = bin2int(crc(df17_str+"000000", encode=True))
+ df17_crc = self.bin2int(self.modes_crc(df17_str+"000000", encode=True))
df17_odd_bytes.append((df17_crc>>16) & 0xff)
df17_odd_bytes.append((df17_crc>> 8) & 0xff)
df17_odd_bytes.append((df17_crc ) & 0xff)
return (df17_even_bytes, df17_odd_bytes)
+
+###############################################################
+
+# 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 .
+
+# the polynominal generattor code for CRC
+
+
+ def modes_crc(self, 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)
+ """
+
+ GENERATOR = "1111111111111010000001001" # Currently don't know what is magic about this number
+
+ msgbin = list(self.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
+
+
+
+ def hex2bin(self, 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(self, binstr):
+ """Convert a binary string to integer. """
+ return int(binstr, 2)
diff --git a/conversions.py b/conversions.py
index b5ca69f..547aef4 100644
--- a/conversions.py
+++ b/conversions.py
@@ -1,59 +1,6 @@
-###############################################################
-# 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 .
-
-# 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