Car Telemetric OBD2 Scanner STM32

This embedded engineering project involved the development of a automotive diagnostic tool designed to extract real-time vehicle telemetry, such as RPM, speed, and engine temperatures—directly from the OBD2 port. The system operates as a Bluetooth Low Energy (BLE) gateway, bridging raw automotive CAN bus data to a custom mobile dashboard for real-time monitoring and analysis.

Technical Implementation & Architecture

To ensure high-speed and reliable data acquisition without bus contention, the firmware architecture is built around a non blocking FreeRTOS state machine running on an STM32G474RE microcontroller. This MCU handles the high-speed engine querying via FDCAN. The extracted telemetry is then precisely serialized and transferred over to a secondary ESP32 microcontroller utilizing a packed struct UART bridge. The ESP32 acts as the dedicated BLE transmitter, pushing the data to the companion Progressive Web App (PWA).

Features:

• FDCAN & UART Protocols: Created a low level communication by interfacing an SN65HVD230 CAN transceiver for automotive bus querying and utilizing UART for inter microcontroller data routing.
• Real-Time Operating System: Utilized FreeRTOS on the STM32 to manage non-blocking state machines, ensuring precise timing for OBD2 data requests and preventing dropped frames during high-speed engine operation.

Technologies I used for this project

Main Technologies

• Embedded C / C++
• FreeRTOS
• STM32 HAL

Hardware & Protocols

• STM32 Nucleo-G474RE Microcontroller
• ESP32 Microcontroller (BLE Gateway)
• SN65HVD230 CAN Transceiver
• FDCAN & UART Protocols
• OBD2 Interface

Companion Software

• OBD2 Dashboard Progressive Web App (PWA)
• OBD2 BLE Transmitter

Results