As computer technology has evolved, there have been two groups of people: the hardware group that understands the machine, and the software group that codes in high-level programming languages. This book puts the two together by providing an understanding of the nuts and bolts of digital devices and implementing hardware operations by coding a microcontroller.We use the Arduino microcontroller, which is embraced by the world-wide maker community of well over 300,000 people of all ages and technical backgrounds. The projects start at ground level and scaffold upward to fun challenges.We begin with a background on digital circuitry and cover the operation of the Arduino microcontroller. From there, we examine digital logic gates, which are the building blocks of computer hardware, and see how they make decisions.Next, we explore how digital devices work with numbers and do arithmetic along with how they count binary numbers. We also see how data moves between points in serial or parallel form as we build and test the circuitry to do the work.The topic of random number generation is explained, and we design a few simple computer games to see how this all works and have some fun. The book leads up to the reader producing a final capstone project. The format of the book is perfect for a digital electronics high school or college course, but easy enough to follow so that anyone with a basic background in DC circuits will have an enjoyable time with the many projects.