September 10, 2025

Rethinking Robot Electronics: Building a Unified, Modular Architecture

In advanced robotics, the most brilliant software can be crippled by the physical reality of its electronic hardware. With tight deadlines and the constant need for last-minute changes, the monolithic electronic architecture easily becomes a complex mess that's difficult to debug, impossible to scale, and a significant barrier to rapid innovation.

As VP of Electronics at ClubTech in CentraleSupélec, I led the initiative to replace this complexity with a clean and standardized ecosystem. The philosophy behind our new system is simple: create a standardized platform that allows any component to connect and communicate seamlessly. We achieved this by designing a common backplane that provides a universal interface for all our custom modules. This interface delivers shared power (

24V

and

5V

), a common ground (

GND

), and a robust communication network using the CAN bus protocol (

CANH

and

CANL

). The choice of CAN was deliberate; it is an industry standard renowned for its reliability in electrically noisy environments, a common characteristic of robots with powerful motors. Each functional component, from a motor driver to a sensor array, is built as a self-contained module. Every module houses its own STM32 microcontroller, allowing it to manage its own operations and communicate intelligently on the network. To ensure physical compatibility, we standardized on single-slot and double-slot form factors, enabling us to build modules of varying complexity that all fit perfectly within the system.

The Anatomy of the Ecosystem

Our architecture is composed of two primary mainboards, each serving a critical role, and a number of Self-Contained modules allowing complete customization

The Command Center: The Raspberry Pi Main Board

3D render of the Raspberry Pi CM5 Main Board

This is the brain of the operation. It hosts a Raspberry Pi Compute Module 5, providing the high-level processing power needed for complex algorithms like navigation, machine vision, and strategic decision-making. To bridge the gap between high-level code and low-level hardware control, the board features two integrated Canable V2.0 interfaces, giving the Raspberry Pi a direct, high-bandwidth link to the entire network of modules. With three of its own module slots, this board forms a compact, self-sufficient core for any robot, capable of managing essential functions right out of the box.

The Expansion Hub: The 10-Slot Backplane

This board is the key to our system's immense scalability. It is, in essence, a pure expansion chassis. Its design is focused on a single task: providing ten additional standardized slots that connect directly into the shared power and communication bus. By connecting one or more of these hubs to the main Controller Board, we can effortlessly scale our robot’s capabilities, adding dozens of motors, sensors, or other peripherals without a single piece of custom wiring.

A Principle of Self-Contained Units

Each module is a self-contained circuit board designed for a specific task, such as controlling a motor or processing sensor data. At the heart of every module is an STM32 microcontroller, which gives it the intelligence to manage its own operations and communicate independently over the shared CAN bus. We standardized their physical design into single-slot and double-slot sizes, allowing any module to be plugged into any available port on the backplane. This "plug-and-play" nature means we can add, remove, or swap the robot's capabilities in moments. Below are a few examples of our modules

MOSFET Power Module

Below is the 3D render of our MOSFET module, allowing us to make use of 3 MOSFETs that can handle up to 10A on the 24V rails. This module takes up one slot on the motherboard

Stepper Motor Driver Module

Below is the 3D render of our stepper driver module allowing us to control two stepper motors just by sending commands to the STM32 via CAN bus. This module takes up two slots on the motherboard

A Transformative Impact

Adopting this modular architecture has yielded profound, tangible benefits for our team and our projects.

Radical Flexibility: We can now reconfigure a robot's entire hardware suite in minutes, not days. Swapping a sensor module for a new motor controller is as simple as unplugging one card and plugging in another.
Effortless Scalability: The system grows with our needs. We can start with a minimal setup on the Controller Board and expand methodically by adding Expansion Hubs, ensuring the architecture never limits the scope of our ambition.
Enhanced Reliability: By eliminating the "rat's nest" of wires and standardizing connections, we have drastically reduced the most common sources of electronic failure. Debugging is now a logical process of isolating a specific module rather than tracing a single wire through a complex loom.
Accelerated Innovation: Our teams can now develop and test new hardware modules in parallel. A new sensor can be perfected on a test bench and, once validated, instantly integrated into the main robot, knowing it will work seamlessly.

This project was more than just an engineering exercise; it was about creating a lasting platform. It has provided Clubtech in CentraleSupélec with a stable, scalable, and professional-grade foundation that will empower us to build more advanced and reliable robots for years to come.

A Modular Electronics Architecture for Advanced Robotics