Real-time heart rate and respiration tracking using embedded systems!
- 🌟 Project Overview
- 🛠️ Hardware Design
- 🎛️ Software Capabilities
- 🚀 Results & Achievements
- 🔧 How to Use
- 🤖 Future Enhancements
- 📝 License
This non-medical biosensor device monitors heart rate (BPM) and respiration rate (breaths per minute) in real time. It uses:
✔ Phototransistor + LED to measure pulse rate via blood flow changes in a finger.
✔ Strain gauge + HX711 ADC to detect respiratory movement through a diaphragm-worn apparatus.
✔ PWM buzzer speaker to trigger alerts when thresholds are exceeded.
✔ Shell command interface for adjusting heart/breath rate limits and viewing data dynamically.
The project is implemented on a TM4C123GXL microcontroller and demonstrates practical signal processing in embedded systems.
Figure 1: Hardware setup for biosensor device
- Microcontroller: TM4C123GXL (ARM Cortex-M4)
- Pulse Sensor: TEPT5700 phototransistor with a red LED
- Respiration Sensor: HX711 ADC + 350Ω strain gauge
- Amplifiers & Filtering: LM358 dual op-amp for signal conditioning
- Buzzer: Alerts users when thresholds are exceeded
Figure 2: Circuit diagram of the amplifier circuit that converts the varying analog signal
Figure 3: Circuit diagram of the speaker
Figure 4: This figure shows the circuitry for the respiratory analysis part of the project The connection of the HX711 involves the DATA and the PD_CLK being connected to the controller. Then a 350 ohms resistor is connected from E+ to A+, E+ to A-, and E- to A+. Afterward, the tip of the TRS jack is connected to the A- terminal, and the shield connects to the E-.
Figure 4: Scope Capture of the circuit
The figure examines the sensor input to the circuit and the final output to the timer CCP0 pin of the controller.
✅ Pulse Detection: Reads LED reflection changes and converts to BPM.
✅ Respiration Detection: Measures strain gauge voltage fluctuations to calculate breath rate.
✅ Data Smoothing: Implements low-pass filtering to remove noise.
💻 Set Limits: Configure min/max heart rate and respiratory thresholds.
💻 Real-time Monitoring: View current BPM & breath rate.
💻 Continuous Reporting: Enable live data streaming to terminal.
💻 Buzzer Alerts: Get notified when values exceed safe ranges.
✔ Accurate real-time heart and breath rate monitoring
✔ Fully functional embedded system with live data feedback
✔ Customizable user interface via shell commands
✔ Compact, low-power, and cost-effective design
1️⃣ Assemble the Circuit: Follow the hardware setup diagram and connect components.
2️⃣ Load the Firmware: Flash the provided firmware onto the TM4C123GXL board.
3️⃣ Open a Serial Terminal: Use 115200 baud, 8N1, no hardware flow control.
4️⃣ Run Commands: Monitor vitals and configure alerts in real time.
> monitor start
Heart Rate: 72 BPM
Respiration Rate: 18 breaths/min🚀 Wireless Data Streaming – Send heart & breath rate to a mobile app via Bluetooth.
🚀 OLED Display Integration – Show real-time vitals on a screen.
🚀 AI-based Anomaly Detection – Detect irregular heartbeats or breathing patterns.