ECG & Heart Rate Live Visualization (Python GUI)

This Python application provides a real-time ECG waveform visualization and heart rate monitoring interface for data transmitted from an STM32F401CCU6 microcontroller via the HC-05 Bluetooth module.

The GUI continuously reads the ECG ADC data and BPM values over serial communication, plots them dynamically using Matplotlib, and displays the heart rate (BPM) numerically.
It also includes a low heart rate alarm that triggers a warning beep when the BPM falls below a threshold.

Features

• Real-time ECG waveform plotting
• Heart rate (BPM) display
• Automatic peak detection (handled in STM32 code)
• Bluetooth serial communication via HC-05
• Low BPM audio alarm
• Connect/Disconnect controls
• Smooth animated graph using Matplotlib and Tkinter

Hardware Setup Overview

Component	Description
STM32F401CCU6	Main controller collecting ECG data
AD8232	ECG analog module
HC-05 Bluetooth Module	Sends ECG & BPM data to the PC
Laptop/PC	Runs this visualization

• The STM32 code sends ECG analog readings and BPM values via Bluetooth.
• The Python script reads these values, displays them as a waveform, and updates the BPM in real time.

Hardware Connection Diagram

                +------------------------+
                |     STM32F401CCU6      |
                +------------------------+
                |                        |
                |  PA0  <--- ECG Out ----|--- AD8232 OUTPUT
                |                        |
                |  PA2  ---> HC-05 RXD   |  (STM32 TX -> HC-05 RX)
                |  PA3  <--- HC-05 TXD   |  (STM32 RX <- HC-05 TX)
                |                        |
                |  3.3V -----------------|--- AD8232 VCC
                |  GND  -----------------|--- AD8232 GND
                |                        |
                +------------------------+

                +-------------------+
                | AD8232 ECG Module |
                +-------------------+
                | OUTPUT  --> PA0   |
                | 3.3V    --> 3.3V  |
                | GND     --> GND   |
                +-------------------+

                +--------------------------+
                |  HC-05 Bluetooth Module  |
                +--------------------------+
                | TXD  --> PA3 (STM32 RX)  |
                | RXD  <-- PA2 (STM32 TX)  |
                | VCC  --> 5V              |
                | GND  --> GND             |
                +--------------------------+

Software Requirements

• Python 3.8+
• Pip (Python package manager)
• Keil uVision5 (STM32 Devvelopment Environment)

Install Required Dependencies

Open a terminal (or Command Prompt) and install the following:

pip install pyserial matplotlib numpy

winsound and tkinter come preinstalled with Python on Windows.

Find Your Bluetooth COM Port (HC-05)

1. Open Device Manager in Windows (Win + X → Device Manager).

2. Expand the Ports (COM & LPT) section.

3. Look for “HC-05 Bluetooth Serial Port” or “Standard Serial over Bluetooth link”.

4. Note the COM Port number (e.g., COM4 or COM7).

5. Update the line below in your Python code to match your COM port:

   SERIAL_PORT = 'COM4'

How to Run the Program

1. Ensure your STM32 + AD8232 + HC-05 setup is powered and paired via Bluetooth.

2. Open Keil uVision5 -> Create new project -> Select STM32F401CCU6 -> CMSIS:CORE,Device:Startup -> Finish.

3. Save the C file below as ecg.c in project directory.

4. Flash the board, build the file and load it into the STM32.

5. Save the Python file below as visualize.py.

6. Press the Reset button present in the STM32.

7. Open a terminal in the same folder and run:

   python visualize.py

8. In the GUI:

   • Enter your correct Serial Port (e.g., COM4)
   • Click Connect
   • The live ECG waveform will appear, and BPM will be displayed on the top-right.

9. If the heart rate drops below 30 BPM (configurable), a warning beep will sound.

Notes

• Ensure that the STM32 UART baud rate matches the BAUD_RATE set in Python (9600 by default).

• If the waveform looks noisy, check grounding and electrode placement.

• To modify alarm sensitivity, change:

  ALARM_THRESHOLD = 30

• To adjust the display length, modify:

  MAX_POINTS = 100

Hardware Setup & Python GUI Output

STM32F401CCU6 connected with AD8232 ECG module and HC-05 Bluetooth module.

Real-time ECG waveform and heart rate (BPM) displayed on the Python GUI.

Contributors

• @Sudharsana Saravanan S
• @Shyam Sundar Raju
• @Dwarakesh V
• @Amarthya Sujai