EDISON DAM060 Logging

#!/usr/bin/python2.7

#
#   Just a quick n' dirty script to read the Data from a VA18B multimeter.
#   This DMM uses the low nibble of 14 bytes to send the lcd segments.
#
#       License: GPL v3. http://www.gnu.org/licenses/gpl-3.0-standalone.html
#

import signal
import sys
import time
import serial
import serial.tools.list_ports
import io
import getopt

interval = '1.0'

ports = list(serial.tools.list_ports.comports())
for p in ports:
    print(p)

def showhelp():
    print( '        va18b.py -i <time in secs> -d <device>')
    print( '   Eg:  va18b.py -i 1.5 -d /dev/ttyUSB1')


try:
    opts, args = getopt.getopt(sys.argv[1:],"hd:i:",['help'])
except getopt.GetoptError:
    print( 'Error: -i, -d option require a value.')
    showhelp()
    sys.exit(1)

for opt, arg in opts:
    if opt in ('-h','--help'):
      showhelp()
      sys.exit(1)
    if opt == '-i':
      interval = arg
    if opt == '-d':
      device = arg

try:
    InpP = 'COM'+input("\nZadej cislo portu na otevreni: ")
    port=serial.Serial(port=InpP,
               baudrate=2400,
               bytesize=serial.EIGHTBITS,
               stopbits=serial.STOPBITS_ONE,
               parity=serial.PARITY_NONE,
               timeout=None)

    if not port.isOpen():
        port.open()

except IOError as err:
    print( '\nError:' + str(err) + '\n')
    sys.exit(1)


def signal_handler(signal, frame):
    port.flushInput()
    port.close()
    sys.exit(0)

signal.signal(signal.SIGINT, signal_handler)

# Every packet is 14 bytes long.
def get_bytes():
    i=0
    substr=''
    while i<=13:
        byte=port.read(1)
        # converting every byte to binary format keeping the low nibble.
        substr += '{0:08b}'.format(ord(byte))[4:]
        i += 1
    return substr

def TF(strn):
    if(strn == '  0.L '):
        return float(9999999999)
    else:
        return float(strn)

def stream_decode(substr):
    ac       = int(substr[0:1])
    dc       = int(substr[1:2])
    auto     = int(substr[2:3])
    pclink   = substr[3:4]
    minus    = int(substr[4:5])

    digit1   = substr[5:12]
    dot1     = int(substr[12:13])
    digit2   = substr[13:20]
    dot2     = int(substr[20:21])
    digit3   = substr[21:28]
    dot3     = int(substr[28:29])
    digit4   = substr[29:36]

    micro    = int(substr[36:37])
    nano     = int(substr[37:38])
    kilo     = int(substr[38:39])
    diotst   = int(substr[39:40])
    mili     = int(substr[40:41])
    percent  = int(substr[41:42])
    mega     = int(substr[42:43])
    contst   = int(substr[43:44])
    cap      = int(substr[44:45])
    ohm      = int(substr[45:46])
    rel      = int(substr[46:47])
    hold     = int(substr[47:48])
    amp      = int(substr[48:49])
    volts    = int(substr[49:50])
    hertz    = int(substr[50:51])
    lowbat   = int(substr[51:52])
    minm     = int(substr[52:53])
    fahrenh  = substr[53:54]
    celcius  = int(substr[54:55])
    maxm     = int(substr[55:56])

    digit = {"1111101":"0",
             "0000101":"1",
             "1011011":"2",
             "0011111":"3",
             "0100111":"4",
             "0111110":"5",
             "1111110":"6",
             "0010101":"7",
             "1111111":"8",
             "0111111":"9",
             "0000000":" ",
             "1101000":"L"}

    value = ("-" if minus else " ") +\
            digit.get(digit1,"") + ("." if dot1 else "") +\
            digit.get(digit2,"") + ("." if dot2 else "") +\
            digit.get(digit3,"") + ("." if dot3 else "") +\
            digit.get(digit4,"")
    value=str(TF(value))

    flags = "".join([ "   AC   |"   if ac     else "",
                      "   DC   |"   if dc     else "",
                      "  Auto  |"   if auto   else "",
                      " Diodet |"   if diotst else "",
                      " Contin |"   if contst else "",
                      "  Capm  |"   if cap    else "",
                      "  Rel   |"   if rel    else "",
                      "  Hold  |"   if hold   else "",
                      "  Minv  |"   if minm   else "",
                      "  Maxv  |"   if maxm   else "",
                      "  LowB  |"   if lowbat else ""])

    units = ("n   "    if nano    else "") +\
            ("u   "    if micro   else "") +\
            ("k   "    if kilo    else "") +\
            ("m   "    if mili    else "") +\
            ("M   "    if mega    else "") +\
            ("%   "    if percent else "") +\
            ("Ohm "    if ohm     else "") +\
            ("Amp "    if amp     else "") +\
            ("Volt"    if volts   else "") +\
            ("Hz  "    if hertz   else "") +\
            ("C   "    if celcius else "")

    return [value + " |" + flags + " " + units, value]

sys.stderr.write('Press any key to make log\n')
sys.stderr.write('Press Ctrl+C to exit.\n\n')

while 1:
    input()
    port.flushInput()
    sleep(0.2)
    substr = get_bytes()
    data = stream_decode(substr)
    print(TF(data[1]))