Script to read SML data packages from a residential meter

pysml.py

#!/usr/bin/env python
# encoding: utf-8
"""
pysml.py
Created by Christian Stade-Schuldt on 2014-10-25.
"""

import sys
import os
import datetime
import serial
import time
import re

# SML regexes
complete_message_regex = '1b1b1b1b01010101.*1b1b1b1b.{8}'
meter_108_regex = '070100010800.{24}(.{8})0177'
meter_208_regex = '070100020800.{24}(.{8})0177'
meter_167_regex = '070100100700.{16}(.{8})0177'

def main():
    ser = serial.Serial('/dev/ttyUSB0', baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=0 )
    tty_error = 0
    t = 10
    if tty_error == 0:
        while t > 0:
            t -=1
            data = ser.read(2048)
            data = data.encode('hex')
            if re.match(complete_message_regex, data):

                m108 = re.search(meter_108_regex, data)
                m208 = re.search(meter_208_regex, data)
                m167 = re.search(meter_167_regex, data)

                if m108 and m208 and m167:
                    m167 = int(m167.group(1),16)
		    # check if value is negative
		    if m167 > 0x7FFFFFFF:
			m167 -= 0x100000000
                    print int(m108.group(1),16)/10000.0
                    print int(m208.group(1),16)/10000.0
		    print m167/10.0

                t = 0
            time.sleep(1)

if __name__ == '__main__':
    main()