IoT based Smart Agriculture Monitoring System

The IoT-based Smart Agriculture Monitoring System operates by integrating a NodeMCU ESP8266 microcontroller with multiple environmental sensors and output actuators to automate farm management. At the heart of the power distribution, a 7805 voltage regulator steps down higher voltages to provide a stable 5V rail, supported by 10uF and 0.1uF capacitors to filter out high-frequency noise and maintain supply stability. The system continuously gathers data using a DHT11 sensor for ambient temperature and humidity, a DS18B20 waterproof probe for precise soil temperature tracking, a soil moisture sensor to evaluate volumetric water content, and an LDR to monitor ambient light levels. These analog and digital signals are processed by the NodeMCU ESP8266, which connects to the cloud via Wi-Fi using the Arduino IDE, Adafruit IO, and the Adafruit MQTT Library, while also fetching external forecasts through the OpenWeatherMap API. Based on sensor feedback and remote commands, the microcontroller triggers higher-power peripherals like a submersible mini water pump and a 12V LED strip. Because these actuators require more current and voltage than the NodeMCU pins can safely source, two TIP122 transistors act as electronic switches, paired with 4.7K and 10K resistors to properly bias the base current and ensure reliable switching control.