The author first described a microcontroller-based implementation of a PLC in a series of articles published in Electronics World magazine between 2008 and 2010. This book is based on an improved version of the project, including:
- Updates to the hardware configuration, with a smaller CPU board and two I/O extension boards that now support 16 inputs and 16 outputs instead of 8
- An increased clock frequency of 20 MHz
- Improvements to several macros
- Flowcharts to help you understand the macros (functions)
In this book, the author provides detailed explanations of hardware and software structures. He also describes PIC Assembly macros for all basic PLC functions, which are illustrated with numerous examples and flowcharts. An accompanying CD contains source files (.ASM) and object files (.HEX) for all of the examples in the book. It also supplies printed circuit board (PCB) (Gerber and .pdf) files so that you can have the CPU board and I/O extension boards produced by a PCB manufacturer or produce your own boards.
Making PLCs more easily accessible, this unique book is written for advanced students, practicing engineers, and hobbyists who want to learn how to build their own microcontroller-based PLC. It assumes some previous knowledge of digital logic design, microcontrollers, and PLCs, as well as familiarity with the PIC16F series of microcontrollers and writing programs using PIC Assembly language within an MPLAB integrated development environment.