Introduction
Automotive lighting systems play an essential role in vehicle safety, visibility, and communication with other road users. In general, these systems can be grouped into two main categories: Front Lighting and Rear Lighting. Both help provide road illumination for the driver and signal the vehicle's actions and presence to surrounding traffic.
Front Lights - General Role and Functions
Front lighting improves the driver's visibility in different driving conditions, including low light, nighttime driving, and adverse weather. It includes several key functions commonly found in modern vehicles, such as:
- Daytime Running Lights (DRL) - increase vehicle visibility during daytime driving
- Turn Lights - indicate the driver's intention to change direction
- Head Lights - provide road illumination during nighttime or low-light conditions
- Fog Lights - improve visibility in fog, rain, snow, or other low-visibility situations
Rear Lights - General Role and Functions
Rear lighting is primarily used to communicate the vehicle's status and intentions to other road users. It includes important functions such as:
- Stop Lights - signal braking actions
- Head Lights - make the vehicle visible from behind
- Turn Lights - indicate the intended direction of travel
- Fog Lights - improve vehicle visibility in low-visibility conditions
Overview
The lighting system presented in this article is developed using a Model-Based Design (MBD) approach. This methodology enables early validation of system behavior, systematic refinement of the control logic, and a direct path from simulation to embedded implementation. The control behavior is modeled in MATLAB/Simulink, where the functionality is structured into modular and reusable components. Stateflow is used to describe the control logic, providing a clear and formal representation of operating modes, state transitions, and event-driven behavior.
The Simulink model runs on the NXP S32K3 platform and communicates with other vehicle nodes via CAN Bus. Message reception and signal handling are managed using the Vehicle Network Toolbox, which simplifies CAN communication by utilizing DBC files without introducing additional hand-written interface code. This integration supports a smooth transition from simulation to embedded deployment through automatic code generation, minimizing the risk of discrepancies between modeled behavior and deployed software.
Target audience:
- Engineers interested in Model-Based Design for automotive applications
- Those learning or experimenting with simulation-based development and control logic
- Anyone using NXP automotive hardware platforms who wants to faster develop complex applications on real embedded systems
Figure 2 - Front Hazard Lights Activated
Context
In this project, separate models are implemented for front and rear lighting to showcase the physical layout of the car and keep the logic simple and easier to test. Each lighting area handles its own functions, while staying synchronized with overall vehicle behavior through standard vehicle communication.
Figure 1 - Front and Rear Lights System highlighted within the EV architecture
All lighting commands are received via the CAN bus, ensuring consistent and predictable behavior for functions such as Daytime Running Lights (DRL), Head Lights, Fog Lights, Turn Indicators, and Stop Lights. Using CAN-based commands reflects standard vehicle communication practices and allows the lighting logic to be evaluated under conditions close to those in a production system.
Incoming CAN messages are processed by the lighting module. Based on vehicle states and received commands, the module:
- interprets CAN signals and system status,
- prioritizes lighting functions and handles fault-related conditions,
- turns on the lights.
This structure keeps responsibilities clear: the CAN layer provides high-level commands, while the lighting control logic handles decision-making and execution. The result is a deterministic and easy-to-follow path from vehicle-level inputs to visible lighting behavior.
In our project, the system uses addressable LEDs, allowing individual control of multiple light segments within each lamp. This enables a realistic representation of modern automotive lighting systems, where lighting units are no longer simple on/off devices but consist of multiple independently controlled segments.
Addressable LEDs rely on a dedicated communication protocol to transfer control data such as color, brightness, and activation timing to each individual LED element. To simplify the integration of this protocol and ensure deterministic behavior, the LED communication was configured and integrated using NXP's Model-Based Design workflow. This approach allows the LED control logic and communication timing to be defined, simulated, and validated directly at model level.
The system behavior can be easily followed from input to output, since each step is clearly defined. CAN messages trigger specific actions, and the result is directly visible in the LEDs. This makes the logic straightforward to understand and verify.
References
Conclusion
This article provides a simple overview of how Model-Based Design can be applied to develop an automotive lighting system using NXP hardware, focusing on the general architecture and design approach. In the following articles, we will explain the configuration, implementation, and deployment of the lighting system on the NXP hardware.