Asyncio serial port logger. This works, but has not been tested for efficiency.

async_serial_logger.py

"""Asyncio serial port logger.

Requirements:

  * pyserial
  * pyserial-asyncio
  * aiofiles

"""
import os
import datetime
import socket
import asyncio
import serial_asyncio
import aiofiles


# Globals
HOSTNAME = socket.gethostname()
FILE = None


async def split_file_every(timeout=2, log_directory='/log/'):
    global FILE

    # Make the log directory if it does not exist
    if not os.path.exists(log_directory):
        os.makedirs(log_directory)
    if log_directory.endswith('/'):
        log_directory = log_directory[:-1]

    while True:
        # Create the file
        datestr = datetime.datetime.now().strftime('%Y-%m-%d-%H.%M.%S')
        filename = '{}/{}-{}EST.dat'.format(log_directory, HOSTNAME, datestr)
        async with aiofiles.open(filename, 'wb') as f:
            FILE = f
            print('Log opened at ' + str(datestr))
            # file_starttime = time.time()  # Not needed anymore

            # Sleep until split
            await asyncio.sleep(timeout * 60)


async def log_data(byts):
    global FILE
    await FILE.write(byts)


class Reader(asyncio.Protocol):
    def connection_made(self, transport):
        print('Connection Started')
        self.transport = transport

    def connection_lost(self, exc):
        print('Connection Closed')
        asyncio.get_event_loop().stop()

    def data_received(self, data):
        global FILE

        print('Data Received', len(data))
        asyncio.get_event_loop().create_task(log_data(data))


if __name__ == '__main__':
    import argparse

    PORT = '/dev/ttyUSB0'
    # PORT = 'COM1'
    BAUDRATE = 921600
    TIMEOUT = 2  # Minutes
    LOG_DIRECTORY = '/log/'

    P = argparse.ArgumentParser(description='Log serial port data to a file.')
    P.add_argument('--port', '--com', type=str, default=PORT, help='Serial com port to open.')
    P.add_argument('--baudrate', '--baud', type=int, default=BAUDRATE, help='Serial port baudrate.')
    P.add_argument('--timeout', '-t', type=float, default=TIMEOUT, help='File timeout in minutes.')
    P.add_argument('--log', '-o', type=str, default=LOG_DIRECTORY, help='Log file directory to write to.')

    ARGS = P.parse_args()
    PORT = ARGS.port
    BAUDRATE = ARGS.baudrate
    TIMEOUT = ARGS.timeout
    LOG_DIRECTORY = ARGS.log

    # Run the asyncio loop
    loop = asyncio.get_event_loop()

    # Create the task that writes the buffer to the file
    loop.create_task(split_file_every(TIMEOUT, log_directory=LOG_DIRECTORY))

    # Create the serial task
    reader = serial_asyncio.create_serial_connection(loop, Reader, PORT, baudrate=BAUDRATE)
    loop.run_until_complete(reader)
    loop.run_forever()

    loop.close()