Files
web2.0-backend/coffee_scale/mqtt.py
T
2017-09-18 23:16:19 +03:00

66 lines
1.7 KiB
Python

import paho.mqtt.client as mqtt
import logging
import datetime
from collections import deque
TOPIC_TEMP = "sik/kiltahuone/kahvivaaka/temperature"
TOPIC_WEIGHT = "sik/kiltahuone/kahvivaaka/weight"
BREWING_DIFFERENTIAL = 60
# setting down the pan creates at least 800 g of weight
BREWING_DIFFERENTIAL_ERROR_MAX = 800
WEIGHT_DEQUE_LENGTH = 20
weight_deque = deque(maxlen=WEIGHT_DEQUE_LENGTH)
latest = {
'last_brew': datetime.datetime.now()
}
def on_connect(client, userdata, flags, rc):
logging.info('Subscribing to all topics on mqtt.sik.party.')
client.subscribe("#")
def on_message(client, userdata, msg):
if msg.topic == TOPIC_TEMP:
latest['temp'] = float(msg.payload.decode('utf-8'))
elif msg.topic == TOPIC_WEIGHT:
weight = float(msg.payload.decode('utf-8'))
latest['weight'] = weight
weight_deque.appendleft(weight)
def on_disconnect(client, userdata, rc):
client.loop_stop(force=False)
if rc != 0:
print("Unexpected disconnection.")
else:
print("Disconnected")
def get_latest():
if len(weight_deque) > 2:
first = weight_deque[0]
last = weight_deque[len(weight_deque) - 1]
diff = first - last # reverse order
if len(weight_deque) < WEIGHT_DEQUE_LENGTH:
brewing = False
else:
if BREWING_DIFFERENTIAL < diff < BREWING_DIFFERENTIAL_ERROR_MAX:
brewing = True
latest['last_brew'] = datetime.datetime.now()
else:
brewing = False
latest['brewing'] = brewing
return latest
client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.on_disconnect = on_disconnect
client.connect("mqtt.sik.party", 1883, 60)