Operational Evaluation of Automatic Watering System Based onESP8266And Blynk Cloudwith Solar Power SupplyOff-Grid

Abstract

Efficient water management in small-scale agricultural applications can be supported through irrigation.loopclosed and remote environmental monitoring. This study evaluates the operational performance of a prototype automatic plant watering system based onInternet of Things (IoT)who usesNodeMCU ESP8266, Blynk Cloud, capacitive soil moisture sensor, temperature-humidity sensorDHT22, relayactive-LOW, and 12 V DC submersible pump. Subsystemoff-grid consisting of a 50 Wp photovoltaic module, solar charge controller PWM, and batteryVRLAA 12 V 12 Ah power supply was used as the prototype power supply during testing. The system was observed for 40 hours on August 3-5, 2026, and generated 41 data records per hour without any interruption.timestampTwo pump actuation events were identified at recorded normalized soil moisture index values ​​of 72.00% and 70.08%, values ​​stored incloudThese values ​​are aggregated and do not always correspond to the instantaneous values ​​when the control triggers the pump. The soil moisture index values ​​in subsequent recordings increased to 74.48% and 78.02%, respectively, reaching a maximum of 87.27%. Ambient temperature ranged from 23.37°C to 39.90°C, while relative humidity ranged from 50.26% to 100.00%. Blinkshows that 1-minute average aggregation can transform short-lived binary pump conditions into fractional values, while the visualizationMAX or LATEST maintain a clearer binary display. The solar subsystem-maintained power availability throughout the test, although the photovoltaic electrical performance has not been quantitatively characterized. Overall, the prototype demonstrates automatic watering, monitoring, andcloud, and operationsoff-grid good during the observation period.