The Internet of Things (IoT) is becoming a major application area for embedded systems. As a result, more and more people are becoming interested in learning about embedded design and programming. Technical colleges and universities are moving away from legacy 8 and 16-bit microcontrollers and are introducing 32-bit embedded microcontrollers to their curriculums. Many IoT applications demand precision, high processing power, and low power consumption. Produced by IBM, Node-RED is an open-source visual editor for wiring the Internet of Things. Node-RED comes with a large number of nodes to handle a multitude of tasks. The required nodes are selected and joined together to perform a particular task. Node-RED is based on flow type programming where nodes are configured and joined together to form an application program. There are nodes for performing complex tasks, including web access, Twitter, E-mail, HTTP, Bluetooth, MQTT, controlling GPIO ports, etc. One particularly nice aspect of Node-RED is that the programmer does not need to learn how to write complex programs. For example, an email can be sent by simply joining nodes together and writing only a few lines of code. The aim of this book is to teach how Node-RED can be used in projects. The main hardware platform used with most of the projects in this book is Raspberry Pi 4. Chapters are included to show how Node-RED can be also be used with Arduino Uno, ESP32 DevKitC, and the ESP8266 NodeMCU microcontroller development boards.