getco2data.py

import atexit
import datetime
import time
import co2meter
import json
import subprocess as subp
import logging


logger = logging.getLogger()
logger.setLevel(logging.DEBUG)


def get_temper_celsius():
    proc = subp.Popen('temper-poll', stdout=subp.PIPE, stderr=subp.PIPE)
    stdout, stderr = proc.communicate()
    if not stdout:
        return None
    for line in stdout.splitlines():
        if not line.startswith('Device'):
            continue
        cval = line.strip().split()[2]
        celsius = float(''.join(
            ch for ch in cval if ch == '.' or ch.isdigit()))
        return celsius

class CachedWriter:

    _to_flush = []

    @classmethod
    def flush_all(cls):
        for writer in cls._to_flush:
            writer.flush()

    @property
    def first(self):
        return self.buffer[0]

    @property
    def last(self):
        if self.buffer:
            return self.buffer[-1]

    def __init__(self, path, flush_limit=100):
        self.path = path
        self.buffer = []
        self.flush_limit = flush_limit

        is_first_call = len(self.__class__._to_flush) == 0
        self.__class__._to_flush.append(self)
        if is_first_call:
            logger.info('registering atexit')
            atexit.register(self.__class__.flush_all)

    def append(self, data):
        self.buffer.append(data)
        if len(self.buffer) > self.flush_limit:
            self.flush()

    def flush(self):
        with open(self.path, 'a') as ofile:
            ofile.write('\n' + '\n'.join(
                json.dumps(rec) for rec in self.buffer))
            logger.info('flushed {} records to {}'.format(
                len(self.buffer),
                self.path,
            ))
            self.buffer = []


if __name__ == '__main__':

    from pprint import pprint

    mon = co2meter.CO2monitor()

    temper_buffer = CachedWriter('temper.jsonl')
    co2meter_buffer = CachedWriter('co2meter.jsonl')

    try:
        while True:
            temper_celsius = get_temper_celsius()
            temper_buffer.append(dict(
                time = datetime.datetime.utcnow().isoformat(),
                epoch = time.time(),
                celsius = temper_celsius,
            ))
            if temper_buffer.last:
                pprint(temper_buffer.last)

            co2meter_time, co2_ppm, co2meter_celsius = mon.read_data()
            co2meter_buffer.append(dict(
                time = co2meter_time.isoformat(),
                epoch = time.time(),
                celsius = co2meter_celsius,
                ppm = co2_ppm,
            ))
            if co2meter_buffer.last:
                pprint(co2meter_buffer.last)
            time.sleep(30)
    except KeyboardInterrupt as e:
        pass
    finally:
        print('exiting...')