Book excerpt: The STM32F103 microcontroller from ST is one of the widely used ARM microcontrollers. The blue pill board is based on STM32F103 microcontroller. It has a low price and it is widely available around the world. This book uses the blue pill board to discuss designing embedded systems using STM32F103. In this book, the authors use a step-by-step and systematic approach to show the programming of the STM32 chip. Examples show how to program many of the STM32F10x features, such as timers, serial communication, ADC, SPI, I2C, and PWM.To write programs for Arm microcontrollers you need to know both Assembly and C languages. So, the text is organized into two parts:1) The first 6 chapters cover the Arm Assembly language programming.2) Chapters 7-19 uses C to show the STM32F10x peripherals and I/O interfacing to real-world devices such as keypad, 7-segment, character and graphic LCDs, motor, and sensor.The source codes, power points, tutorials, and support materials for the book is available on the following website: http: //www.NicerLand.co