Python source code for generating manchester encoded data packets

Use with HackRF, GNU Radio and LRS pagers.

lrs_pager.py

@@ -0,0 +1,124 @@
+#!/usr/bin/python
+
+"""
+Written by: Tony Tiger 6/2019
+
+This program generates manchester encoded data packets for LRS pagers and GNU Radio.
+
+Output file name: pager.bin
+
+Watch the YouTube video for more information: https://www.youtube.com/watch?v=ycLLb4eVZpI
+
+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/>.
+"""
+
+import sys
+import re
+import struct
+
+
+def encode_manchester( bin_list ):
+
+      pre = []  # create extra preambles to wake up the pager
+      for x in range(0,50): 
+            pre.append('1')
+            pre.append('0')
+
+      l = re.findall('.', "".join( pre + bin_list  ) )  # join the preamble and the rest of the packet
+
+      m = []
+      print '\n'
+      print "".join(str(x) for x in l)  # convert list to string
+
+      for x in l:   # convert to manchaster coding
+           if( x == '0'):
+               m.append(1)
+               m.append(0)
+
+           if( x == '1'):
+               m.append(0)
+               m.append(1)
+      return m
+
+
+# calculate the crc
+def calculate_crc( pre, sink_word, rest_id, station_id, pager_n, alert_type ):
+
+    l = re.findall('..', pre + sink_word + rest_id + station_id +  pager_n + '0000000000' + alert_type  )
+
+    bin_array = []
+    for c in l:
+         bin_array.append ( (format( int(c, 16) , '08b')))
+
+    sum=0
+    for b in bin_array:
+         sum +=  int(b , 2)
+
+    print '\n{0} {1} {2} {3} {4} {5} {6} {7}'.format( pre, sink_word, rest_id, station_id, pager_n, '0000000000', alert_type, format( ( sum % 255), '02x' ))
+    bin_array.append( format( ( sum % 255), '08b') )
+    return bin_array
+
+
+
+
+##########################################
+# main program start                     #
+##########################################
+
+try:
+    rest_id=int(raw_input('\nEnter restaurant id 0-255: '))
+except ValueError:
+    print "Not a number"
+
+try:
+    pagers=(raw_input('Enter one or more pager numbers 0-1023 : '))
+except ValueError:
+    print "Not a number"
+
+pager_list = []
+pager_list = map( int, re.split('\s+',pagers))
+
+print '1 Flash 30 Seconds\n2 Flash 5 Minutes\n3 Flash/Beep 5X5\n4 Beep 3 Times\n5 Beep 5 Minutes\n6 Glow 5 Minutes\n7 Glow/Vib 15 Times\n10 Flash/Vib 1 Second\n68 beep 3 times\n'
+
+
+try:
+    alert_type=int(raw_input('Enter alert type: '))
+except ValueError:
+    print "Not a number"
+
+
+handle = open('pager.bin', 'wb')
+
+data = []
+for pager_n in pager_list:
+    crc_out = ( calculate_crc( format(11184810, '06x') , format( 64557,'04x'), format(rest_id, '02x'), '0', format( pager_n  ,'03x' ), format(alert_type, '02x') ) )
+
+    data = encode_manchester( crc_out )
+    [ data.append(0) for x in range(0,100) ]
+
+    print '\n';
+    print "".join(str(x) for x in data)
+    print '\n'
+
+    for d in data:
+        if d == 0:
+            handle.write(struct.pack('f', .0001)) 
+        elif d == 1:
+            handle.write(struct.pack('f', 1)) 
+        else:
+            print "Error detected in data"
+            sys.exit()
+
+handle.close()    
+