scripts/onboard_led_temp.py

"""
https://ac-microcourses.readthedocs.io/en/latest/courses/hello-world/1.4.1-onboard-led-temp.html

permalink: https://github.com/AccelerationConsortium/ac-microcourses/blob/07dc9a0286ded2e21ea64f02d8ae697717e786b9/docs/courses/hello-world/1.4.1-onboard-led-temp.ipynb
"""

COURSE_ID = "<your_id_here>"  # UPDATE THIS TO YOUR ID

command_topic = f"{COURSE_ID}/onboard_led"
sensor_data_topic = f"{COURSE_ID}/onboard_temp"

HIVEMQ_USERNAME = "sgbaird"
HIVEMQ_PASSWORD = "D.Pq5gYtejYbU#L"
HIVEMQ_HOST = "248cc294c37642359297f75b7b023374.s2.eu.hivemq.cloud"

import paho.mqtt.client as mqtt
import json
from queue import Queue

sensor_data_queue: "Queue[dict]" = Queue()


def get_paho_client(
    sensor_data_topic, hostname, username, password=None, port=8883, tls=True
):

    client = mqtt.Client(
        mqtt.CallbackAPIVersion.VERSION2, protocol=mqtt.MQTTv5
    )  # create new instance

    def on_message(client, userdata, msg):
        sensor_data_queue.put(json.loads(msg.payload))

    # The callback for when the client receives a CONNACK response from the server.
    def on_connect(client, userdata, flags, rc, properties=None):
        if rc != 0:
            print("Connected with result code " + str(rc))
        # Subscribing in on_connect() means that if we lose the connection and
        # reconnect then subscriptions will be renewed.
        client.subscribe(sensor_data_topic, qos=1)

    client.on_connect = on_connect
    client.on_message = on_message

    # enable TLS for secure connection
    if tls:
        client.tls_set(tls_version=mqtt.ssl.PROTOCOL_TLS_CLIENT)
    # set username and password
    client.username_pw_set(username, password)
    # connect to HiveMQ Cloud on port 8883 (default for MQTT)
    client.connect(hostname, port)
    client.subscribe(sensor_data_topic, qos=2)

    return client


def send_and_receive(client, command_topic, msg, queue_timeout=60):
    client.publish(command_topic, msg, qos=2)

    client.loop_start()

    while True:
        sensor_data = sensor_data_queue.get(True, queue_timeout)
        client.loop_stop()
        return sensor_data


client = get_paho_client(
    sensor_data_topic, HIVEMQ_HOST, HIVEMQ_USERNAME, password=HIVEMQ_PASSWORD
)

onboard_temp = send_and_receive(client, command_topic, "toggle", queue_timeout=30)
print(onboard_temp)