A Literature Survey on Iot-Based Embedded Systems for Monitoring and Control

IoT-based embedded systems integrate sensors, microcontrollers, communication networks and software platforms to connect physical devices with digital applications. They sense the environment, process the readings locally, and transmit useful data to a monitoring platform; depending on the application, the controller can also drive an actuator automatically or act on a remote user command. This paper surveys the literature on such systems under six headings: IoT foundations and reference architectures, low-cost Wi-Fi/Bluetooth microcontrollers such as the ESP32, wireless and messaging protocols, cloud and edge platforms, application domains (smart homes, agriculture, healthcare, industry and environmental monitoring), and security. Twenty-two peer-reviewed works are compared in a summary table. The survey finds that low-cost hardware and lightweight protocols such as MQTT have made monitoring-and-control systems easy to build, but that power consumption, sensor calibration, reliable connectivity and device security remain weak points in most reported prototypes. Based on these gaps, a general ESP32-based monitoring-and-control system is proposed, with local threshold-based automation, MQTT/HTTP data transfer to a cloud dashboard, and design rules for reliability, low power and secure communication.