This book was first developed as a short technical course for students in the subjects of electronics and computer science in their early study years. The course aims to introduce the concept of embedded electronic control systems based on the ubiquitous 8-bit microcontrollers, specifically the 8051 microcontroller. The course was initially developed in the year 2000, more than two decades ago now. However, despite its age, over time the course proved to be extremely useful for students and I have received many requests over the years to reproduce the document as a free internet resource, as presented here.