CAN Data Logger

All modern cars have many onboard computers known as Electronic Control Units or ECU's. Each ECU controls an aspect of the car's operation.  There's an ECU for the engine, another for the transmission and a third for the body.  Most cars have ECU's for crash detection, anti-lock brakes and environmental controls. Modern cars can have more than 20 ECU's. 

These ECUs communicate with each other using a Controller Area Network (CAN).  For example, the Transmission ECU might send vehicle speed to the Body ECU for display on the dashboard. 

There is a great deal of information in CAN messages that can be useful to drivers. If you tow a large camper, it can be important to monitor transmission temperature.  Our focus is on information like this that is not available on the dashboard. 

Unfortunately, vehicle makers don't often publish their CAN data formats and that's where CAN Data Loggers come in. The picture shows a prototype CAN data logger  we use to collect data from the vehicles we support. It's based on an ESP32 micro controller that connects directly to the car's CAN bus. It stores data on an SD card and has WiFi and Bluetooth connectivity.

That data is analyzed in a process known as reverse engineering. We use this information to build applications that provide drivers with information that's not available anywhere else.