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.''