Design and Development of an IoT-Based System for Monitoring and Automatic Control of Nutrient Delivery During the Generative Phase of Chili Plants Using Firebase

Irfan Sanjaya Sipayung (Fakultas Ilmu Komputer dan Teknologi Informasi, Universitas Muhammadiyah Sumatera Utara)
Zuli Agustina Gultom (Fakultas Ilmu Komputer dan Teknologi Informasi, Universitas Muhammadiyah Sumatera Utara)

Madani: Multidisciplinary Scientific Journal
Vol 4, No 9 (2026): October 2026

This research aims to design and develop an Internet of Things (IoT) system based on the ESP32 microcontroller and the Firebase Realtime Database cloud platform to monitor and automatically control nutrient solution quality in real-time. The research and development (R&D) methodology was applied using a Three-Tier architecture approach. The system integrates a pH-4502C sensor and a KS0429 TDS sensor as the input layer, alongside a relay module and a DC pump as actuators for threshold-based automatic control (setpoint). Experimental results demonstrate high reading validity, with the pH sensor achieving an average accuracy rate of 99.29% (RMSE = 0.0486 pH; MAPE = 0.71%) and the TDS sensor reaching 99.38% (RMSE = 8.46 PPM; MAPE = 0.62%). A 24-hour reliability test proved consistent system performance without any instances of system crashes or data loss, maintaining a Relative Standard Deviation (RSD) below 1%. Data transmission latency to the ChiliNutri Pro web dashboard remained remarkably low, with a response time ranging between 1.1 and 1.9 seconds. Furthermore, when external disturbances were introduced, the control logic embedded in the ESP32 firmware responsively executed autonomous dosing of concentrated nutrients until the TDS parameter stabilized back to the target value of 800 PPM. The developed system successfully eliminates human error and is ready for implementation to support nutrient absorption optimization in modern chili cultivation.