Implementing Cpld Based Interfaces For Sensors And Actuators In A Mechatronic Design Course

Complex Programmable Logic Devices ( CPLDs) are a class of programmable logic device that are commonly used to implement complex digital designs on a single integrated circuit. Current applications of CPLDs in the field of computer engineering include the implementation of bus controllers, address decoders, communication interfaces, etc. This paper outlines a novel application for CPLDs in the field of mechatronics. A low cost, microcontroller-based data acquisition system has been developed that incorporates both a user programmable microcontroller and a user reconfigurable CPLD. The CPLD basically provides reconfigurable digital I/O that permits the implementation of interfaces for smart sensors and actuators. Typical applications include quadrature decoder/counter interfaces for optical encoders, stepper motors controllers and Pulse-Width Modulation (PWM) motor drives. By incorporating a CPLD that supports In-System Programmability (ISP) the target device can be reprogrammed by the user for a variety of applications without removing it from the host system.