Development of an Ultrasonic Pest Repellent System Based on ESP32 and the Internet of Things (IoT)

Fatimah, Siti
Lestari, Inda
Lestari, Cyndi
Larita, Nadia Putri
Husniyah, Dini Milatul
Sinensis, Arini Rosa
Firdaus, Thoha

Justek : Jurnal Sains Dan Teknologi
Vol 9, No 1 (2026): March

Pest attacks on agricultural land often result in a significant decrease in crop yields. This study aims to develop an IoT-based pest repellent system integrating ultrasonic waves and remote control. The method involves an ESP32 microcontroller, a PIR sensor, and a PAM8403 amplifier with a piezoelectric tweeter. The system was evaluated through laboratory calibration and real-field implementation in East OKU. This device features automatic mode (ultrasonic triggers >20 kHz) and manual mode via the Blynk application. Quantitative results show a maximum detection range of 5 meters with a 110-degree coverage angle. The system achieves a stable 30 kHz output and real-time notifications with an average latency of less than 1 second. IoT integration enables farmers to monitor and control the device remotely, increasing crop protection efficiency in dynamic rice field environments.