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.
|OPERATING VOLTAGE||8-18V DC|
|OPERATING CURRENT||63 mA|
|BATTERYSAVER™ MODE||< 2 mA|
|OPERATING TEMPERATURE||-4º to 131º F (-20º to 55º C)|
All legislated OBD II protocols:
- ISO 15765-4 (CAN 250/500 kbps, 11/29 bit)
- ISO 14230-4 (Keyword Protocol 2000)
- ISO 9141-2 (Asian, European, Chrysler)
- SAE J1850 VPW (GM)
- SAE J1850 PWM (Ford)
Non-legislated OBD protocols:
- ISO 15765
- ISO 11898 (raw CAN)
- SAE J1939 OBD protocol used in heavy-duty vehicles
STN IC Comparison Chart
|Compatible with ELM327 AT command set|
|Extended ST command set|
|PowerSave™ sleep/wake triggers|
|Automatic protocol detection algorithm|
|Support for all legislated OBD-II protocols|
|Support for Single-Wire CAN (SW-CAN)|
|Support for Medium-Speed CAN (MS-CAN)|
|Support for SAE J1939|
|Advanced security options|
|Recommended for new designs|
|Unit pricing (10k pieces; USD)||