Build a Simple Automatic Plant Watering System using Arduino

This automated plant watering system operates through an integrated loop of sensing, processing, and actuation managed by the Arduino Uno R4 WiFi. The FC-28 soil moisture sensor continuously measures the volumetric water content in the soil by evaluating changes in electrical conductivity between its probe tracks, outputting an analog voltage signal to the microcontroller. The Arduino Uno R4 WiFi processes this incoming data against a predefined moisture threshold. When the soil dries out beyond the acceptable limit, the microcontroller changes the digital output state connected to the 5V single-channel relay module. This relay acts as an electrically operated switch, closing the circuit to power the 5V water pump from the external power supply (via a 12V DC jack power adapter or 5V USB-C power adapter). As the pump runs, it delivers water to the plant until the FC-28 sensor detects sufficient moisture recovery, prompting the Arduino to deactivate the relay and stop the pump. Additionally, because the Arduino Uno R4 WiFi features onboard wireless connectivity, it communicates with the Blynk IoT platform and mobile app. This allows the system to transmit real-time moisture telemetry to a personal computer or smartphone, enabling remote monitoring, manual overrides, and automated status updates without requiring physical proximity to the hardware setup.