Boost gauges are a popular addition to turbocharged cars, allowing drivers to monitor the pressure being generated by the turbocharger. While pre-installed boost gauges are common in some newer models, many older vehicles lack this feature. This guide will demonstrate how to build a custom “Boost Obd2” gauge using readily available components and an Arduino, providing a real-time boost reading directly from your car’s OBD-II port. This approach eliminates the need for complex mechanical installations and allows for a clean, easily removable setup.
Understanding the Components of Your Boost OBD2 Gauge
This boost obd2 gauge relies on three core components:
- OBD-II to USB Converter: This acts as the bridge between your car’s computer and the Arduino. Choose a converter based on the ELM327 chip, as it provides a serial interface for easy communication. We’ll modify it to remove the unnecessary USB interface.
- Arduino Nano: This microcontroller will process data from the OBD-II converter and control the visual display. The Arduino Nano is a compact and versatile choice for this project.
- Neopixel Ring: This circular array of LEDs provides a visually appealing way to represent boost pressure. The Neopixel ring’s individually addressable LEDs allow for dynamic and colorful representations of boost levels.
Building the Boost OBD2 Circuit
The OBD-II converter needs modification. Remove the USB interface chip, leaving the serial connection points exposed. Connect the converter to the Arduino using RX and TX lines for serial communication, and provide power using the Arduino’s 5V and GND pins.
The Neopixel ring connects to the Arduino using a single data line. A photoresistor, connected to an analog pin on the Arduino, allows for automatic brightness adjustment based on ambient light.
Power for the entire system can be drawn from the car’s OBD-II port. However, be aware that pin 16 provides constant power. For a gauge that powers on and off with the ignition, utilize a switched power source like the cigarette lighter or, in some car models (like Subaru), a specific pin on the OBD-II port itself.
Addressing Potential Issues: The Check Engine Light
Adding additional load to the OBD-II converter’s power supply can sometimes trigger a check engine light due to communication errors on the CAN bus. To mitigate this, enhance the power supply’s stability by adding extra capacitors. A 100µF capacitor on the 12V input and two 22µF capacitors on the 5V output are recommended.
Boost OBD2 Firmware and Functionality
The Arduino firmware utilizes standard OBD-II commands (PID 0Bh for intake manifold absolute pressure and PID 33h for barometric pressure) to calculate boost. It subtracts barometric pressure from manifold absolute pressure to determine the boost level.
The Neopixel ring displays boost using a straightforward visual representation. The top LED indicates zero boost, with blue LEDs representing vacuum (negative boost) and red LEDs indicating positive boost. Each LED represents a specific pressure increment, with brightness variations indicating finer pressure changes.
Installing and Using Your Boost OBD2 Gauge
The assembled boost obd2 gauge can be conveniently mounted on the windshield using a suction cup or magnets. Simply plug the OBD-II connector into your car’s diagnostic port, and the gauge will power on with the ignition.
Experiment with different driving conditions and observe the boost behavior. Note how boost levels change with throttle input, engine speed, and gear selection.
Conclusion: Enjoy Your Boost OBD2 Gauge
This DIY boost obd2 gauge offers a cost-effective and informative way to monitor your turbocharged engine’s performance. By understanding the basic principles of OBD-II communication and Arduino programming, you can create a customized gauge tailored to your specific needs. Remember to drive responsibly and prioritize safety on the road. While this gauge provides valuable insights into your engine’s operation, it should not encourage reckless driving. Enjoy the satisfaction of building and using your own custom boost gauge!
