isstracker.py

import ephem
from array import array
import socket
import time
import sys

def sendScratchCommand(cmd):
   n = len(cmd)
   a = array('c')
   a.append(chr((n >> 24) & 0xFF))
   a.append(chr((n >> 16) & 0xFF))
   a.append(chr((n >>  8) & 0xFF))
   a.append(chr(n & 0xFF))
   try:
      PORT = 42001
      HOST = '127.0.0.1'

      scratchSock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      scratchSock.connect((HOST, PORT))
      #print "data len" , n
      scratchSock.sendall(a.tostring() + cmd)
      time.sleep(0.1)
      scratchSock.shutdown(socket.SHUT_RDWR)
      scratchSock.close()
   except:
      print sys.exc_info()[0]
      print ("Failed to send to Scratch")



observer = ephem.Observer()
observer.lon, observer.lat = '-2.24', '53.48'


try:
   while True:
      observer.date = ephem.now()   # 12:22:56 EDT
      #print gatech.date
      obj =  ephem.readtle('ISS','1 25544U 98067A   16111.74054971  .00005749  00000-0  93439-4 0  9994',
'2 25544  51.6441 344.5739 0001791  50.1935 345.8459 15.54298106996046'
         )#ephem.Jupiter()
      obj.compute(observer)
      alt = int(( 180 /3.1415926 * float(obj.alt)))
      az = int(( 180 /3.1415926 * float(obj.az)))
      dist = int(obj.range /1000)
      print alt,az,dist
      sendScratchCommand('sensor-update alt ' + str(alt) + ' direction ' + str(az)+ ' dist ' + str(dist))
      time.sleep(1)
except KeyboardInterrupt:
       pass