Many modern vehicles lack dedicated coolant temperature gauges on the dashboard, a crucial instrument for preventing engine overheating. While commercial OBD2 HUD displays offer coolant temperature monitoring, vehicle compatibility can be limited. This article explores using an Arduino with a CAN Bus shield to directly decode OBD2 data and display the engine coolant temperature, offering a versatile DIY solution.
Choosing the right hardware is the first step. For a compact setup, a small form-factor Arduino board paired with a compatible CAN Bus shield is ideal. Several Arduino-compatible CAN Bus shields are available, ensuring you select one that fits your Arduino and project needs.
Next, software is key. Fortunately, various CAN Bus libraries are available for Arduino. These libraries simplify the process of sending and receiving CAN messages. Explore libraries provided by shield manufacturers or community-developed options to find one that suits your coding style and shield compatibility. Look for examples and documentation to get started quickly.
The final piece is understanding OBD2 and CAN Bus protocols to extract the coolant temperature. OBD2 standards dictate specific Parameter IDs (PIDs) for accessing sensor data. Engine coolant temperature PID is standardized, but consulting OBD2 documentation or online resources will confirm the correct PID and data format. You’ll need to write Arduino code to send a request for this PID over the CAN Bus and then parse the received data to extract the temperature value.
By combining Arduino, a CAN Bus shield, and freely available libraries and documentation, monitoring your vehicle’s coolant temperature becomes an accessible and customizable DIY project. This approach bypasses compatibility issues with commercial displays and provides a deeper understanding of your vehicle’s data communication.
