This book is about the Arduino microcontroller and the Arduino concept. The visionary Arduino represented a new innovation in microcontroller hardware in 2005, the concept of open source hardware, making a broad range of computing accessible for all.This book, “Arduino VIII: Portenta Machine Control,” is an accessible primer on industrial control and programmable logic controller concepts for those without a deep instrumentation background. An understanding of basic circuit theory is an appropriate prerequisite for the book. The three main goals for the book are: explore accessible Arduino Portenta Machine Control industrial control products; learn the fundamentals of programming using ladder logic; and explore related sensors and interface concepts. We use multiple examples throughout the book and conclude with an instrumented greenhouse project.