This is a fully open-source car datalogger that reads engine data using the OBD2 interface in real time and stores it on an SD card. It also stores GPS data. All communication is done directly by the MCU without a translator chip like ELM327 or STN1110. The datalogger supports all CAN and K-Line OBD2 protocols. All hardware fits into an off-the-shelf OBD2 connector enclosure.
This project is available on Github.