Development of a CAN Bus datalogger for recording sensor data from an internal combustion ECU

The CAN Bus protocol is widely used in various technological areas such as industrial, medical, or automotive. Developed by Bosch in the 1980s, this protocol is predominantly used in commercial vehicles to reduce emissions with the introduction of electronic control. It makes data from sensors and diagnostics codes available through the OBD-II connector. Many vendors sell devices and software tools to read CAN Bus data in a friendly way in exchange for a monthly fee. The aim of this work is to develop a low cost OBD-II device controlled with an open-source software. A dedicated board using an Arduino Nano with a microSD slot and on-board LCD screen was developed for this purpose. This device collects information emitted by a vehicle ECU with the MCP2515 through an OBD-II connector. This article presents the stages of the design and construction of the board, and the validation tests carried out to determine its functionality as a datalogger. Finally, a graph that plots the sensor data recorded from the OBD-II datalogger is presented as RPM vs. speed.