refactor: Improve code readability and performance in app.py

app.py

@@ -1,12 +1,3 @@
-"""
-Fan control using EMC2101 and a Canakit RPi 5 fan
-
-https://chatgpt.com/share/e29312a2-a589-4a07-afb8-4778506a47e9
-
-https://github.com/AccelerationConsortium/ac-training-lab/tree/main/src/ac_training_lab/picow/fan-control
-
-"""
-
 import json
 import queue
 import threading
@@ -24,15 +15,15 @@ st.title("Motor Control Panel")
 # Description and context
 st.markdown(
     """
-This application accesses a public test demo of a fan controller located in Send
-speed commands to the fan and visualize the RPM data.
-
-See
-[ac_training_lab/picow/fan-control](https://github.com/AccelerationConsortium/ac-training-lab/tree/main/src/ac_training_lab/picow/fan-control) # noqa: E501
-[[permalink](https://github.com/AccelerationConsortium/ac-training-lab/tree/db19bda95f2a81909da7dbcd7c5dc76e8d1ee6b7/src/ac_training_lab/picow/fan-control)] # noqa: E501
-for context.
-
- You may also be
+This application accesses a public test demo of a motor control located in
+Toronto, ON, Canada (as of 2024-07-27). Send speed commands to the motor and
+visualize the RPM data.
+
+For more context, you
+can refer to this [Colab
+notebook](https://colab.research.google.com/github/sparks-baird/self-driving-lab-demo/blob/main/notebooks/4.2-paho-mqtt-colab-sdl-demo-test.ipynb)
+and the [self-driving-lab-demo
+project](https://github.com/sparks-baird/self-driving-lab-demo). 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.
@@ -125,7 +116,6 @@ def plot_rpm_data(ax1, ax2, rpm_data):
     ax1.set_ylabel("RPM", fontsize=14)
     ax1.set_title("Motor RPM over Time", fontsize=16)
 
-    # For any additional plots or processing in ax2, currently showing RPM data only.
     ax2.clear()
     ax2.plot(times, rpm_values, "-o", color="blue")
     ax2.set_ylim(0, max(1.1 * max(rpm_values), 1.1))  # Set fixed y-axis limits
@@ -133,24 +123,32 @@ def plot_rpm_data(ax1, ax2, rpm_data):
     ax2.set_ylabel("RPM (scaled)")
     ax2.set_title("RPM Data Stream")
 
-    plt.pause(0.01)
     st.pyplot(fig)
 
 
 # Function to continuously receive RPM data
 def receive_rpm_data():
     rpm_data = []
+    global fig, ax1, ax2
     fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(10, 8))
     plt.ion()
 
     start_time = time.time()
+    timeout = 15  # Timeout duration in seconds
+
     while True:
-        data = rpm_data_queue.get(True)
-        elapsed_time = time.time() - start_time
-        data["time"] = elapsed_time
-        rpm_data.append(data)
-        plot_rpm_data(ax1, ax2, rpm_data)
-        st.write("RPM Data Received:", data)
+        try:
+            data = rpm_data_queue.get(timeout=timeout)
+            elapsed_time = time.time() - start_time
+            data["time"] = elapsed_time
+            rpm_data.append(data)
+            plot_rpm_data(ax1, ax2, rpm_data)
+            st.write("RPM Data Received:", data)
+        except queue.Empty:
+            st.error(
+                f"No RPM data received for {timeout} seconds. Please check the system."
+            )
+            break
 
 
 # Start a background thread to receive RPM data