rpigrovetempvalues.py

rpigrovetempvalues.py

# Copyright (c) Bruno Capuano. All rights reserved.
# Licensed under the MIT license. See LICENSE file in the project root for full license information.
# Using the Python Device SDK for IoT Hub:
#   https://github.com/Azure/azure-iot-sdk-python
# Azure IoT dependencies installed with >> pip install azure-iot-device
# read temp and humi from DHT11 Sensor
# read values are triggered device message with the information

import random
import time
import seeed_dht
import os
import threading
from azure.iot.device import IoTHubDeviceClient, Message

CONNECTION_STRING = "CNN STRING GOES HERE"
refresh_interval = 1

# Define the JSON message to send to IoT Hub.
MSG_TXT = '{{"temperature": {temperature},"humidity": {humidity}}}'

def twin_update_listener(client):
    global refresh_interval
    while True:
        patch = client.receive_twin_desired_properties_patch()  # blocking call
        print("Twin desired properties patch received:")
        print(patch)
        refreshIntervalKey = 'RefreshInterval'
        if refreshIntervalKey in patch:
            refresh_interval = patch[refreshIntervalKey]
            print(f"Refresh Interval Updated to {refresh_interval}")

def iothub_client_init():
    # Create an IoT Hub client
    client = IoTHubDeviceClient.create_from_connection_string(CONNECTION_STRING)
    return client

def iothub_client_telemetry_sample_run():
    global refresh_interval
    try:
        client = iothub_client_init()

        twin_update_listener_thread = threading.Thread(target=twin_update_listener, args=(client,))
        twin_update_listener_thread.daemon = True
        twin_update_listener_thread.start()

        print ( "IoT Hub device sending periodic messages, press Ctrl-C to exit" )
        sensor = seeed_dht.DHT("11", 12)

        while True:
            # read current values from sensor
            humi, temp = sensor.read()
            msg_txt_formatted = MSG_TXT.format(temperature=temp, humidity=humi)
            message = Message(msg_txt_formatted)

            # Add a application property to the message with humi and temp
            message.custom_properties["temperature"] = temp
            message.custom_properties["humidity"] = humi

            # Send the message.
            print( "Sending message: {}".format(message) )
            client.send_message(message)
            time.sleep(refresh_interval)

    except KeyboardInterrupt:
        print ( "IoTHubClient sample stopped" )

if __name__ == '__main__':
    print ( "El Bruno - Sample telemetry message" )
    print ( "Press Ctrl-C to exit" )
    iothub_client_telemetry_sample_run()