CAN-DAQ: An open-source, cost-effective data capture device and software for automotive research

Modern systems, from vehicles to industrial testbenches, generate vast amounts of CAN bus data, yet researchers and developers lack affordable, open-source tools for its capture and analysis. While commercial tools are cost-prohibitive and existing open-source options often lack integrated hardware or mature software, acquiring this data is essential for subsystem validation (such as powertrains, safety systems, and sensors), ECU development, and network security analysis, with real-time graphing providing immediate insight. We present CAN-DAQ, a complete hardware-software platform that bridges this gap, matching the core features of commercial systems at a fraction of the cost. It combines an ESP32-based hardware interface with a flexible Python-based software and SDK, featuring high-resolution real-time visualization and a robust SQL backend. CAN-DAQ supports all classic CAN baud rates from 25 kbps to 1 Mbps and achieves a maximum sampling frequency of 1 kHz, reliably capturing 1000 CAN frames per second. As a fully open-source solution, it provides a foundation for users to build custom real-time data analytics applications. The system's effectiveness was validated through comprehensive testing of its data reception, transmission, and sampling capabilities, demonstrating reliable operation against commercial-grade automotive CAN interfaces.