This is Arduino library for communicating with vehicles over the OBD2 K-Line interface, using ISO 9141 and ISO 14230 (KWP2000) protocols.
It allows you to connect your Arduino and ESP boards to your car's ECU (Engine Control Unit) and read diagnostic data like DTCs (Diagnostic Trouble Codes), live sensor data, and more.
- OBD-II communication over K-Line
- Supports ISO9141 and ISO14230 protocols
- Read DTCs, live data, freeze frame, and more
- 5-baud init and fast init supported
- Works with Arduino boards (e.g., UNO, Mega)
- Works with ESP boards (e.g., ESP32, ESP8266)
The R6 resistor in this schematic is designed for 3.3V microcontrollers. If you are using a 5V microcontroller, you need to change the R6 value to 5.3kΩ.
Additionally, I have observed that many test devices use a 1kΩ value for R4. However, according to the K-Line documentation, the recommended value for R4 is 510Ω. It is advisable to follow this value. That being said, using 1kΩ for R4 will not cause any issues in the circuit. However, if you prefer to adhere to the documentation, 510Ω is the recommended value.
