On-Board Diagnostics, Second Generation (OBD-II) is a set of standards for implementing a computer based system to control emissions from vehicles. It was first introduced in the United States in 1994, and became a requirement on all 1996 and newer US vehicles. Other countries, including Canada, parts of the European Union, Japan, Australia, and Brazil adopted similar legislation. A large portion of the modern vehicle fleet supports OBD-II or one of its regional flavors.
Among other things, OBD-II requires that each compliant vehicle be equipped with a standard diagnostic connector (DLC) and describes a standard way of communicating with the vehicle’s computer, also known as the ECU (Electronic Control Unit). A wealth of information can be obtained by tapping into the OBD bus, including the status of the malfunction indicator light (MIL), diagnostic trouble codes (DTCs), inspection and maintenance (I/M) information, freeze frames, VIN, hundreds of real-time parameters, and more.
STN1110 is an OBD to UART interpreter that can be used to convert messages between any of the OBD-II protocols currently in use, and UART. It is fully compatible with the de facto industry standard ELM327 command set. Based on a 16-bit processor core, the STN1110 offers more features and better performance than any other ELM327 compatible IC.
- Fully compatible with the ELM327 AT command set
- Extended ST command set
- UART interface (baud rates from 38 bps to 10 Mbps)
- Secure bootloader for easy firmware updates
- Superior automatic protocol detection algorithm
- Large memory buffer
- Voltage input for battery monitoring
- Available in SPDIP, SOIC and QFN-S packages
- RoHS compliant
- Solid, field-tested software. STN1110 runs the same proven code that powers the popular OBDLink family of PC-based OBD interfaces. Thanks to its large user base, any problems are discovered and corrected quickly.
- Large OBD message buffer. STN1110 has over five times as much RAM as its nearest competitor, virtually eliminating BUFFER OVERFLOW errors.
- Automatic protocol detection algorithm is continuously fine-tuned to insure that STN1110 will connect to the widest array of vehicles, even those that do not fully conform to the OBD standard.
PowerSave Sleep/Wakeup Triggers
The diagram shows the various triggers available in the STN11xx family of ICs. Please refer to the STN11xx PowerSave Functionality documentation for more details.
All legislated OBD II protocols:
- ISO 15765-4 (CAN)
- ISO 14230-4 (Keyword Protocol 2000)
- ISO 9141-2 (Asian, European, Chrysler vehicles)
- SAE J1850 VPW (GM vehicles)
- SAE J1850 PWM (Ford vehicles)
Non-legislated OBD protocols:
- ISO 15765
- ISO 11898 (raw CAN)
SAE J1939 OBD protocol used in heavy-duty vehicles