dht-mqtt.py

# SPDX-FileCopyrightText: 2022 Farshid Tavakolizadeh
# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

# RUN:
# BROKER=localhost python read.py

import time
import board
import adafruit_dht
import requests
import os
import paho.mqtt.client as paho
import uuid

broker=os.environ['MQTT_BROKER']
port=os.environ['MQTT_BROKER_PORT']
topic_prefix=os.environ['MQTT_TOPIC_PREFIX']
client_id_prefix=os.environ['MQTT_CLIENT_ID_PREFIX']
pin=os.environ['PIN']
sensor=os.environ['SENSOR']
interval=os.environ['INTERVAL']

# Initialize the sensor at the given pin:
dhtDevice = getattr(adafruit_dht, sensor)(pin)

# Initialize the MQTT client
mqtt_client=paho.Client(client_id=client_id_prefix+"-"+str(uuid.uuid4()))

def on_connect(client, userdata, flags, rc):
    print("Connected: {}".format(paho.connack_string(rc)))

def on_disconnect(client, userdata, rc):
    print("Disonnected: {}".format(paho.connack_string(rc)))

mqtt_client.on_connect = on_connect
mqtt_client.on_disconnect = on_disconnect
mqtt_client.connect_async(broker,int(port))
mqtt_client.loop_start()

while True:
    try:
        #print("----------------------------")
        temperature = dhtDevice.temperature
        humidity = dhtDevice.humidity
        print("Temp: {:.1f}C  Humidity: {}% ".format(temperature, humidity))

        rc,_=mqtt_client.publish(topic_prefix+"temperature", temperature, retain=True)
        if rc != 0:
            print("Publish temperature error: {}".format(paho.error_string(rc)))

        rc,_=mqtt_client.publish(topic_prefix+"humidity", humidity, retain=True)
        if rc != 0:
            print("Publish humidity error: {}".format(paho.error_string(rc)))


    except RuntimeError as error:
        # Errors happen fairly often, DHT's are hard to read, just keep going
        print(error.args[0])
        time.sleep(2.0)
        continue
    except Exception as error:
        dhtDevice.exit()
        mqtt_client.loop_stop()
        raise error

    time.sleep(int(interval))