temperature-logger-interface/temp_log.py

#! /usr/bin/env python
import glob
import io
import platform
import Queue
import serial
import sys
import threading
import time
defaultSerialPort = '/dev/ttyACM0'
defaultVersion = 0

def list_serial_ports():
    """Lists serial ports, taken from http://stackoverflow.com/questions/11303850/what-is-the-cross-platform-method-of-enumerating-serial-ports-in-python-includi"""
    system_name = platform.system()
    if system_name == "Windows":
        # Scan for available ports.
        available = []
        for i in range(256):
            try:
                s = serial.Serial(i)
                available.append(i)
                s.close()
            except serial.SerialException:
                pass
        return available
    elif system_name == "Darwin":
        # Mac
        return glob.glob('/dev/tty*') + glob.glob('/dev/cu*')
    else:
        # Assume Linux or something else
        return glob.glob('/dev/ttyS*') + glob.glob('/dev/ttyUSB*') + glob.glob('/dev/ttyACM*')


class ParseException(Exception):
    """Parser Exceptions"""
    pass


def parse_line(line, version = defaultVersion):
    """Parses a line and returns an array index by name of the data available"""
    # @TODO This could be a class based versioning?
    data = dict()
    if (version == 0):
        line = line.split(' ')
        try:
            data['temperature'] = float(line[-2])
        except Exception, e:
            pass
    else:
        raise ParseException('Unimplemented line version', version)
    return data


def threaded_reader(source, dataQueue, commandQueue):
    try:
        ser = serial.Serial(source, baudrate=9600, parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE, bytesize=serial.EIGHTBITS)
        sio = io.TextIOWrapper(io.BufferedRWPair(ser, ser))
        ser.isOpen()
    except Exception, e:
        dataQueue.put({'exception' : str(e)})
        return
    buffer = ''
    runTime = ''
    cmd = ''
    while True:
        try:
            cmd = commandQueue.get_nowait()
        except Queue.Empty:
            pass
        if cmd == 'stop':
            break
        try:
            data = parse_line(ser.readline(), defaultVersion)
            runTime = time.time()
        except Exception, e:
            dataQueue.put({'exception' : str(e)})
        if data and runTime:
            item = {'time' : runTime, 'data' : data}
            dataQueue.put(item)
    # close out the fds
    ser.close()


def main(args = sys.argv):
    # @TODO switch to parse args or similar
    # @TODO parse of temperature logger line version
    serialPort = defaultSerialPort
    lineVersion = defaultVersion
    try:
        serialPort = sys.argv[1]
    except Exception, e:
        pass
    ser = serial.Serial(port=serialPort, baudrate=9600, parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE, bytesize=serial.EIGHTBITS)
    sio = io.TextIOWrapper(io.BufferedRWPair(ser, ser))
    ser.isOpen()
    buffer = ''
    while True:
        try:
            buffer = ser.readline()
            data = parse_line(buffer, lineVersion)
            if data:
                print unicode(time.time()) + ',' + unicode(data['temperature'])
                sys.stdout.flush()
        except Exception, e:
            sys.stderr.write(str(e) + '\n')
            continue

if __name__ == '__main__':
    main(sys.argv)