A Microprocessor-Based Serial Multiplex System is Combined with Simple Momentary Switches to Provide Ergonomically Improved Driver Input Controls for Traditional Body Electrical Functions

The desire to achieve a less bulky, more rational vehicle wire harness has led designers to consider Serial Multiplexed design approaches. One of the inherent advantages of a Serial Multiplexed design is the separation of the logical switching function from the power switching function. As a result, the designer is able to provide the vehicle´s operators with input control points that are much more convenient in their use. Since these control operations are entirely logical in nature and totally separate from the high-current switching that ultimately occurs at the load devices, small, inexpensive, momentary switches in combination with microprocessor-controlled visual and/or audible feedback devices can be used. This permits the power of a microprocessor-based distributed input/output (I/O) control to be employed to process the driver´s (and passenger´s) commands to the vehicle´s body electrical system. The result is a design facility that permits an effective ergonomic interface to be created in a manner that has never before been possible for the automotive switch designer. The operator is presented with a control input that is in fact the long-awaited ``Smart Switch.´´