How to Use SX1278 LoRa 433MHz Module (RA-02) to Control a Relay with Transmitter & Receiver
Published at : 18 Dec 2025
In this video, we will demonstrate how to use the SX1278 LoRa 433MHz module (RA-02) to control a relay remotely. You'll learn how to set up both the transmitter and receiver using Arduino boards to wirelessly control a relay for switching loads over long distances. This project is perfect for IoT applications and offers a practical solution for wireless control systems.
Here are the core specifications of the SX1278 LoRa Module in point form: Frequency Range: 433 MHz (also available in 868 MHz and 915 MHz variants). Modulation: LoRa and FSK. Output Power: Up to +20 dBm (100 mW), adjustable. Receiver Sensitivity: Up to -137 dBm (LoRa). Data Rate: 0.3 kbps to 27 kbps (LoRa); 1.2 kbps to 300 kbps (FSK). Range: Up to 10–15 km (open area), 2–3 km (urban environment). Bandwidth: 7.8 kHz to 500 kHz (LoRa); 1.2 kHz to 100 kHz (FSK). Low Power Consumption: Sleep mode 1 µA, Transmit mode 120 mA, Receive mode 10–15 mA. Spreading Factor: SF7 to SF12 for range and data rate adjustment. Interface: SPI communication. Operating Voltage: 2.6V to 3.6V (typically 3.3V). Operating Temperature: -40°C to +85°C. Antenna: External antenna required (whip antenna for 433 MHz). Package: Small PCB form for embedded use.