import serial
from dsmr_parser.parsers import TelegramParser
SERIAL_SETTINGS_V2_2 = {
'baudrate': 9600,
'bytesize': serial.SEVENBITS,
'parity': serial.PARITY_NONE,
'stopbits': serial.STOPBITS_ONE,
'xonxoff': 0,
'rtscts': 0,
'timeout': 20
}
SERIAL_SETTINGS_V4 = {
'baudrate': 115200,
'bytesize': serial.SEVENBITS,
'parity': serial.PARITY_EVEN,
'stopbits': serial.STOPBITS_ONE,
'xonxoff': 0,
'rtscts': 0,
'timeout': 20
}
def is_start_of_telegram(line):
return line.startswith('/')
def is_end_of_telegram(line):
return line.startswith('!')
class SerialReader(object):
def __init__(self, device, serial_settings, telegram_specification):
self.serial_settings = serial_settings
self.serial_settings['port'] = device
self.telegram_parser = TelegramParser(telegram_specification)
def read(self):
"""
Read complete DSMR telegram's from the serial interface and parse it
into CosemObject's and MbusObject's
:rtype dict
"""
with serial.Serial(**self.serial_settings) as serial_handle:
telegram = []
while True:
line = serial_handle.readline()
line = line.decode('ascii')
# Telegrams need to be complete because the values belong to a
# particular reading and can also be related to eachother.
if not telegram and not is_start_of_telegram(line):
continue
telegram.append(line)
if is_end_of_telegram(line):
yield self.telegram_parser.parse(telegram)
telegram = []