The Obd2 Click board provides an unparalleled opportunity to delve into the intricate diagnostic systems of modern vehicles. Powered by the robust STN1110 Multiprotocol OBD to UART Interface from ScanTool Technologies, this click board acts as a sophisticated bridge, enabling seamless communication with your car’s Electronic Control Unit (ECU). Whether you need to interact via CAN, K LINE, L LINE, or J1850 protocols, the OBD2 click simplifies the process. The integrated STN1110 IC expertly manages requests sent from your microcontroller through a UART interface, translating and relaying responses from the complex ECU network back to you.
The power of the STN1110 chip lies in its core. Built around a high-speed 16-bit processor and equipped with a substantial memory buffer, it ensures efficient and reliable data handling. Automatic protocol detection removes complexity, while full compatibility with the ELM327 and extended ELM327 AT command sets offers a familiar and versatile command structure. Supporting UART speeds up to 10 Mbps, the OBD2 click is more than capable for demanding applications, making it ideal for creating custom vehicle dashboards, advanced OBD data loggers, professional-grade automotive diagnostic scan tools, and a wide array of other innovative projects.
Understanding OBD-II and How OBD2 Click Simplifies Access
OBD, or On-Board Diagnostics, is a standardized system that has revolutionized vehicle control and diagnostics. Since its inception in the 1980s and through its evolution to OBD-II, it has transformed from simple warning lights into a comprehensive digital diagnostic standard. OBD-II meticulously defines communication protocols and connector types, ensuring uniformity across different vehicle makes and models.
At the heart of OBD-II are PIDs, or Parameter IDs. These standardized identifiers are used to request specific data points from the vehicle’s ECU. The ECU responds with values corresponding to these PIDs, providing insights into various vehicle parameters. The OBD-II standard outlines 10 operational modes, with manufacturers having the flexibility to implement a subset or add proprietary modes. Each PID response is strictly defined, ensuring consistent data interpretation across different systems.
The STN1110 chip on the OBD2 click acts as an intelligent interpreter, converting messages between the diverse OBD-II protocols and the straightforward UART interface. Its adherence to the ELM327 command set makes it immediately accessible to developers familiar with this widely adopted standard. Furthermore, the OBD-II standard mandates a universal Diagnostic Link Connector (DLC) in all compliant vehicles. This standardized connector ensures that the OBD2 click and similar tools can interface with a vast range of vehicles using a common physical connection.
To ensure robust communication across the varied physical layers used in vehicle diagnostic networks, the OBD2 click integrates essential supporting components. The MCP2561, a high-speed CAN transceiver compliant with ISO-11898, manages CAN signal conversion. For K Line, L Line, and J1850 signals, the LM339 quad differential comparator IC translates these into the necessary digital format for the STN1110. An additional analog pin on the STN1110 allows for direct car battery voltage measurement. This feature is invaluable for troubleshooting UART communication issues and provides a quick voltage check via a simple command or direct measurement from the onboard voltage divider.
Visual feedback is crucial during development and diagnostics. The OBD2 click incorporates four LEDs to monitor data flow. OBD RX/TX LEDs indicate data activity on the OBD side, while UART RX/TX LEDs reflect communication on the microcontroller side. A PWR LED confirms power to the click board, and a BAT LED signals the presence of battery voltage at the OBD connector. The OBD2 click utilizes a standard D-Sub 9 connector (DB9), compatible with readily available OBDII cables (sold separately).
Note: An OBDII cable is not included with the OBD2 click package.
Once the initial protocol auto-detection is complete (potentially requiring ignition to be on and an initialization AT command), the STN1110 handles the complex communication with the vehicle ECU automatically. Retrieving vehicle system status becomes as simple as sending basic AT commands via the UART pins. MikroElektronika provides user-friendly libraries to streamline communication between the OBD2 click and your microcontroller. Comprehensive documentation details the full range of AT commands available for advanced control and data access.
Specifications
| Type | CAN, OBD
