#!/usr/bin/python3
import os
import time
import sys
import Adafruit_DHT as dht
import paho.mqtt.client as mqtt
import json
import datetime
#
# Sensor should be set to Adafruit_DHT.DHT11, Adafruit_DHT.DHT22, or Adafruit_DHT.AM2302.
sensor = dht.DHT11
pin = 4

BROKER = 'localhost'

# Data capture and upload interval in seconds.
INTERVAL=15

sensor_data = {'date': 0, 'temperature': 0, 'humidity': 0}

next_reading = time.time()

client = mqtt.Client()

# Connect to BROKER using default MQTT port and 60 seconds keepalive interval
client.connect(BROKER, 1883, 60)

client.loop_start()

try:
    while True:
        humidity,temperature = dht.read_retry(sensor, pin)
        humidity = round(humidity, 2)
        temperature = round(temperature, 2)
        print(u"Temperature: {:g}u00b0C, Humidity: {:g}%".format(temperature, humidity))
        sensor_data['temperature'] = temperature
        sensor_data['humidity'] = humidity
        sensor_data['date'] = datetime.datetime.now().replace(microsecond=0).isoformat()

#         client.publish('test_channel', json.dumps(sensor_data), 1)
        client.publish('test_channel', json.dumps(sensor_data), 2)

        next_reading += INTERVAL
        sleep_time = next_reading-time.time()
        if sleep_time > 0:
            time.sleep(sleep_time)
except KeyboardInterrupt:
    pass

client.loop_stop()
client.disconnect()

1547597521: Saving in-memory database to /var/lib/mosquitto/mosquitto.db.