This project features the development of a functional prototype for an Automotive Body Control Module (BCM), specifically focused on a Power Window System. Utilizing an ESP32 microcontroller, the system integrates mechatronic actuator control with a robust self-diagnostic algorithm and environmental monitoring.
The software architecture was designed under Safety-Critical System principles, prioritizing hardware safety and passenger integrity through proactive data bus failure detection.
Actuator response to temperature changes and diagnostic alerts.
- Microcontroller: ESP32 DevKit V1 (Dual-Core, 240MHz).
- Language: Embedded C++ (Object-Oriented Programming).
- Sensors/Actuators: * DHT22 (Cabin environment sensor).
- Servo Motor (Torque actuator simulation for window movement).
- 16x2 LCD (Human-Machine Interface / HMI).
- Simulation: Wokwi Embedded Systems Simulator.
The system operates via a Finite State Machine (FSM) architecture to ensure deterministic behavior in vehicle operations:
- Health Monitor Module: Prior to any physical execution, the system validates the integrity of the DHT22 sensor signal. If a null value (
NaN) is detected, the system enters a Safety Lockout state. - Comfort Module: If internal cabin temperature exceeds 30.0°C, the system automatically triggers the actuator for forced ventilation.
- HMI Module: Provides real-time reporting of window status and diagnostic alerts on the LCD screen.
To comply with automotive quality standards, the following event matrix was implemented:
| Detected Event | Fail-Safe Action | Visual Indicator |
|---|---|---|
| DHT22 Signal Loss | Mechatronic operation suspension | Red LED (D2) + LCD Alert |
| Temp > 30.0°C | Controlled window opening | Status: OPEN on LCD |
| System Integrity OK | Standard operation enabled | Green LED (D14) |
| Component | ESP32 Pin | Function |
|---|---|---|
| Servo PWM | D13 | Window position control |
| DHT22 Data | D15 | Environmental data bus |
| Red LED | D2 | Critical Failure Alert |
| Green LED | D14 | Status: System OK |
| LCD RS/E | D19 / D18 | Parallel data bus control |
| LCD D4-D7 | D27, D26, D25, D33 | Interface data bus |
- Import the
sketch.inofile into Wokwi. - Install the required libraries via the Library Manager:
LiquidCrystalDHT sensor libraryESP32Servo
- Run the simulation and manipulate the DHT22 sensor to observe the system's diagnostic response.
Leslye Hernandez Jimenez
LinkedIn: View Profile Email: hdezj.leslye@gmail.com