#!/bin/python

import time
import datetime
import serial
from decimal import *
import thread
import os, sys
import struct

TTY_GEIGER = '/dev/ttyUSB0'

geiger_counts = 0

# Get Geiger data from Geiger Counter
def geiger_thread(name, dly):
    global geiger_counts

    geiger = serial.Serial()
    geiger.baudrate = 57600
    geiger.port = TTY_GEIGER

    try:
        geiger.open()
    except:
        print "Geiger is not connected, can't open " + TTY_GEIGER
        return

    data = ""
    print "Geiger opening port.."
    while True:
        # read data from the serial port - 17 bytes
        try:
            geiger.write("<GETCPM>>");

            data = geiger.read(2)

            geiger_counts = (int (struct.unpack("<L", data[1]+""+data[0]+"\x00\x00")[0]))

            time.sleep(1)
        except:
            print "> Geiger Data stream failed?"


# start thread for handling user commands
thread.start_new_thread(geiger_thread, ("thread #1",1,))

# CPM is refreshed each second - start this in the loop
print "CPM count:" + str(geiger_counts)