Discover how to use a limit switch with an Arduino UNO R4, how to write code for Arduino UNO R4 to read the state and event of a limit switch, and how to program the Arduino UNO R4 step by step. Detailed instructions, code, wiring diagrams, video tutorials, and explanations for each line of code are provided to assist you in getting started with Arduino UNO R4 quickly. For more Arduino UNO R4 tutorials, visit Newbiely.com.