This book is about the Arduino microcontroller and the Arduino concept. The visionary Arduino team 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 VI: Bioinstrumentation,” is an accessible primer on bioinstrumentation 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 microcontroller programming and interfacing concepts; investigate the source and measurement of biomedical signals; and develop skills to design and implement biomedical instrumentation.