CAN-DAQ: An Open-Source, Cost-Effective Data Capture Device and Software for Automotive Research

The CAN-DAQ (Controller Area Network Data Acquisition) system is an open-source, cost-effective platform for automotive data acquisition and analysis. Modern vehicles generate large volumes of CAN bus data, yet affordable and reliable tools for academic and research applications remain limited. CAN-DAQ facilitates real-time data capture from vehicle subsystems—including powertrains, safety systems, and sensors—enabling applications such as electronic control unit (ECU) development, hardware-in-the-loop (HIL) testing, and in-vehicle network security analysis. The system supports standard CAN baud rates of 125 kbps, 250 kbps, 500 kbps, and 1 Mbps, and is compatible with any CAN Database Container (DBC) file for automatic signal decoding and interpretation. A central feature of CAN-DAQ is its real-time graphing functionality, which provides high-resolution visualization of vehicle parameters based on DBC definitions, while robust data logging and storage facilitate long-term trend analysis and diagnostic evaluations.

The core hardware is built around the ESP32-S3 DevKitC1, selected for its robust performance and future-proof connectivity options such as USB-OTG, Wi-Fi, and Bluetooth, ensuring both longevity and flexibility over older alternatives. Communication with the CAN bus is achieved using an MCP2561 CAN transceiver, preferred over the obsolete MCP2551 because of its simpler upgrade path to the MCP2561FD. The transceiver is integrated with the ESP32-S3 to support CAN 2.0 communication across standard baud rates. Embedded firmware, developed in C++ with the ESP-IDF framework, configures the ESP32-S3's TWAI (Two-Wire Automotive Interface) and manages real-time CAN data acquisition as well as USB communication. In parallel, the PC-side software is implemented in Python using Tkinter and Matplotlib for plotting, while the Cantools library is used to parse incoming CAN messages according to definitions provided by a user-supplied DBC file.

The design also incorporates a USB 2.0 interface via a micro-B connector with data transfer rates up to 3 Mbps to ensure reliable, high-speed communication with a host PC. To safeguard data integrity, the hardware disables the ESP32’s debug log output using a pull-up resistor on GPIO46. The MCP2561 transceiver’s standby (STBY) pin—unused by the default software—is tied to ground with a 10 kΩ resistor for stability, while also being routed to GPIO 4 for potential future customization. The complete design is implemented on a compact printed circuit board (PCB) created with KiCAD. This integrated solution, combining advanced hardware, efficient firmware, and comprehensive PC-side software, is demonstrated in research environments for real-time parameter monitoring and data-driven system analysis, providing a versatile platform for automotive diagnostics, industrial automation, and cybersecurity research.