Design and Implementation of a Custom CAN-LTE IoT Gateway for Remote ECU Diagnosis

The Internet of Things (IoT) has transitioned from being primarily associated with consumer-oriented devices to playing a pivotal role in professional and safety-critical environments, notably within the industrial and automotive sectors. This study dives deep into the conceptualization, architecture, and subsequent validation of a sophisticated CAN gateway, designed to seamlessly integrate IoT functionalities through an LTE module. This gateway is adept at reading and clearing diagnostic trouble codes while simultaneously extracting essential parameter data from Electronic Control Units (ECUs). This multifarious endeavor intersects various technological domains: IoT PCB Design: The nucleus of the system is a custom IoT printed circuit board (PCB). This board is characterized by its integration of the LTE SIM7600-H module and an STM32 microcontroller. The design was meticulously crafted, following which post-manufacturing validations were conducted to ensure its operability and efficiency in real-world scenarios. Diagnosis Protocols in Automotive Systems: This research places a significant emphasis on the Unified Diagnostic Services (UDS) protocol. This protocol, which has widespread adoption within the automotive sector, is pivotal for diagnostics and calibration management. The communication layer, meticulously developed in the C programming language, is embedded on the IoT board, thus transforming it into a diagnostic gateway. Moreover, a similar embedding is done into the BMS ECU, thereby facilitating the read/clear functionality pertinent to diagnostic trouble codes and the extraction of functional parameters from the ECU. Secure Protocol Communication in IoT: Safeguarding data integrity and ensuring confidentiality remain paramount, especially in the context of the Internet of Things. AWS IoT Core emerges as the cornerstone for secure broker communication. This security is fortified with the integration of MQTT utilizing both TLS/SSL for secure data transmission and AES-128 encryption for data at rest and data in transit. Design and Implementation of Backend Infrastructure: The system's backbone is composed of an intricate infrastructure that leverages a Kubernetes cluster coupled with Docker containers, all hosted on an Ubuntu environment. Dedicated Python scripts serve as intermediaries between the AWS IoT Core and the local system, overseeing tasks ranging from data encryption to decryption and consequent storage in a MongoDB database. Additionally, a customized dashboard amplifies the user experience by offering real-time visualization of the ECU data. This is complemented by a SQL-driven login mechanism, which ensures robust user authentication. The culmination of this expansive research manifests itself as a cutting-edge CAN gateway. This gateway adeptly bridges the dissemination of real-time ECU data with intuitive user interactivity. The findings underscore the versatility of the gateway, which considers it suitable for deployment across both vehicular and broad-spectrum industrial ecosystems.