app.py

import json
import queue
import time
import paho.mqtt.client as mqtt
import streamlit as st
import matplotlib.pyplot as plt
from datetime import datetime, timezone

# Initialize Streamlit app
st.title("Fan Control Panel")

# Description and context
st.markdown(
    """
This application accesses a public test demo of a small computer fan (Canakit
RPi 5 fan) controlled by a Pico W microcontroller via an EMC2101 fan controller.
Send speed commands to the motor and visualize the RPM data.

For context, see the [fan control
code](https://github.com/AccelerationConsortium/ac-training-lab/tree/main/src/ac_training_lab/picow/fan-control)
[[permalink](https://github.com/AccelerationConsortium/ac-training-lab/tree/a8b9cad0dc8c162bdff20c0d0fdff2f45c5f0012/src/ac_training_lab/picow/fan-control)]
. You may also be interested in the Acceleration Consortium's ["Hello World"
microcourse](https://ac-microcourses.readthedocs.io/en/latest/courses/hello-world/index.html)
for self-driving labs.
"""
)

# MQTT Configuration
with st.form("mqtt_form"):
    HIVEMQ_HOST = st.text_input(
        "Enter your HiveMQ host:",
        "248cc294c37642359297f75b7b023374.s2.eu.hivemq.cloud",
        type="password",
    )
    HIVEMQ_USERNAME = st.text_input("Enter your HiveMQ username:", "sgbaird")
    HIVEMQ_PASSWORD = st.text_input(
        "Enter your HiveMQ password:", "D.Pq5gYtejYbU#L", type="password"
    )
    PORT = st.number_input(
        "Enter the port number:", min_value=1, max_value=65535, value=8883
    )
    PICO_ID = st.text_input("Enter your Pico ID:", "test-fan", type="password")

    # Slider for fan speed
    SPEED = st.slider(
        "Select the Fan Speed (0-100%):", min_value=0, max_value=100, value=50
    )

    submit_button = st.form_submit_button(label="Send Speed Command")

# Topics
COMMAND_TOPIC = f"fan-control/picow/{PICO_ID}/speed"
SENSOR_DATA_TOPIC = f"fan-control/picow/{PICO_ID}/rpm"

# Queue for incoming sensor data
rpm_data_queue = queue.Queue()

# Initialize or load session state variables
if "rpm_data" not in st.session_state:
    st.session_state.rpm_data = []

if "elapsed_times" not in st.session_state:
    st.session_state.elapsed_times = []

if "initial_timestamp" not in st.session_state:
    st.session_state.initial_timestamp = None


# Singleton: https://docs.streamlit.io/develop/api-reference/caching-and-state/st.cache_resource
@st.cache_resource
def create_paho_client(tls=True):
    client = mqtt.Client(protocol=mqtt.MQTTv5)
    if tls:
        client.tls_set(tls_version=mqtt.ssl.PROTOCOL_TLS_CLIENT)
    return client


# Define setup separately since sensor_data is dynamic
def setup_paho_client(
    client, sensor_data_topic, hostname, username, password=None, port=8883
):
    def on_message(client, userdata, msg):
        rpm_data_queue.put(json.loads(msg.payload))

    def on_connect(client, userdata, flags, rc, properties=None):
        if rc == 0:
            print("Connected successfully")
            client.subscribe(sensor_data_topic, qos=1)
        else:
            print(f"Connection failed with code {rc}")

    client.on_connect = on_connect
    client.on_message = on_message

    client.username_pw_set(username, password)
    client.connect(hostname, port)
    client.loop_start()  # Start non-blocking loop

    return client


def send_command(client, command_topic, msg):
    print("Sending command...")
    result = client.publish(command_topic, json.dumps(msg), qos=2)
    result.wait_for_publish()  # Ensure the message is sent

    if result.rc == mqtt.MQTT_ERR_SUCCESS:
        print(f"Command sent: {msg} to topic {command_topic}")
    else:
        print(f"Failed to send command: {result.rc}")


# Function to plot RPM data
fig, ax = plt.subplots()


def plot_rpm_data(elapsed_times, rpms, placeholder):
    ax.clear()  # Clear the previous plot

    # Filter data to only include the last 90 seconds
    current_time = elapsed_times[-1]
    filtered_times = [time for time in elapsed_times if current_time - time <= 90]
    filtered_rpms = rpms[-len(filtered_times) :]

    ax.plot(filtered_times, filtered_rpms, marker="o")
    ax.set_xlabel("Time (s)")
    ax.set_ylabel("RPM")
    ax.set_title("Fan RPM Over Time")
    ax.xaxis.set_major_locator(plt.MaxNLocator(10))  # Show max 10 ticks on x-axis
    plt.xticks(rotation=45)  # Rotate x-axis labels for better readability
    placeholder.pyplot(fig)


# Publish button
if submit_button:
    if not PICO_ID or not HIVEMQ_HOST or not HIVEMQ_USERNAME or not HIVEMQ_PASSWORD:
        st.error("Please enter all required fields.")
    else:
        command_msg = {"speed": SPEED}

        st.info(f"Sending speed command {command_msg} to Pico ID {PICO_ID}...")

        client = create_paho_client(tls=True)

        client = setup_paho_client(
            client,
            SENSOR_DATA_TOPIC,
            HIVEMQ_HOST,
            HIVEMQ_USERNAME,
            password=HIVEMQ_PASSWORD,
            port=int(PORT),
        )

        send_command(client, COMMAND_TOPIC, command_msg)

        # Create a placeholder for the plot
        plot_placeholder = st.empty()

        # Continuously fetch RPM data and update the plot
        while True:
            try:
                data = rpm_data_queue.get(timeout=30)
                rpm = data["rpm"]
                current_timestamp = datetime.fromtimestamp(
                    data["utc_timestamp"], tz=timezone.utc
                )

                if st.session_state.initial_timestamp is None:
                    st.session_state.initial_timestamp = current_timestamp

                elapsed_time = (
                    current_timestamp - st.session_state.initial_timestamp
                ).total_seconds()

                st.session_state.rpm_data.append(rpm)
                st.session_state.elapsed_times.append(elapsed_time)

                plot_rpm_data(
                    st.session_state.elapsed_times,
                    st.session_state.rpm_data,
                    plot_placeholder,
                )
            except queue.Empty:
                st.error("No sensor data received within the timeout period.")
                break

        # Stop the MQTT loop
        client.loop_stop()