I Controlled Devices 4 Km Away Without Internet Using LoRa (RYLR998)

by TechnoSAP in Circuits > Arduino

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I Controlled Devices 4 Km Away Without Internet Using LoRa (RYLR998)

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Introduction

In many remote areas, Wi-Fi and Internet connectivity are either unavailable or unreliable. For applications such as agriculture, industrial automation, remote monitoring, and long-range control systems, a communication method that works without Internet access is extremely valuable.

In this project, I demonstrate how to use the REYAX LoRa RYLR998 module to control devices wirelessly over long distances without relying on Wi-Fi, GSM, or any Internet connection. The system uses LoRa (Long Range) technology to establish direct communication between two devices.

The project was tested in real-world conditions, achieving reliable communication at distances of up to 4 kilometers. This makes it suitable for smart farming, remote equipment control, telemetry systems, IoT applications, and research & development (R&D) projects.

In this Instructable, I will explain the hardware setup, wiring connections, programming, testing procedure, and the results obtained during the field test.

Supplies

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2 × REYAX RYLR998 LoRa Modules

2 × ESP32 Development Boards (or Arduino Boards)

2 × LoRa Antennas

Breadboard

Jumper Wires

USB Cables

Power Bank or Battery Pack

Laptop/PC for Programming

Relay Module (Optional)

LED for Testing (Optional)

Circuit Diagram and Connections

FTDI-RYLR998.png
LORA Transmitter Circuit Diagram.png
LORA Receiver Circuit Diagram.png

Step 1: Understanding the REYAX LoRa RYLR998 Module

Before building the project, it is important to understand the REYAX RYLR998 LoRa module.

The RYLR998 is a long-range wireless communication module based on LoRa technology. Unlike Wi-Fi or GSM modules, it does not require Internet access, routers, or cellular networks to communicate.

Key Features:

  1. Long-range communication up to several kilometers
  2. Low power consumption
  3. UART serial communication
  4. Suitable for IoT and remote-control applications
  5. Works with Arduino, ESP32, and Raspberry Pi

In this project, two RYLR998 modules are used. One acts as the transmitter and the other as the receiver, enabling wireless communication over a distance of up to 4 km during field testing.

Transmitter Side Code


This code will send a signal from the transmitter side to turn the LED on or off.


#define LED_PIN 13

unsigned long previousMillis = 0;
const long interval = 1000;

void setup() {
Serial.begin(115200);
pinMode(LED_PIN, OUTPUT);

delay(1000);

Serial.println("AT+ADDRESS=0");
delay(500);

Serial.println("AT+NETWORKID=5");
delay(500);
}

void loop() {

unsigned long currentMillis = millis();

if (currentMillis - previousMillis >= interval) {

previousMillis = currentMillis;

Serial.println("AT+SEND=1,6,Hello!");

digitalWrite(LED_PIN, HIGH);
delay(100);
digitalWrite(LED_PIN, LOW);
}
}

Reciever Code


#define LED_PIN 13

String receivedData = "";

void setup() {
Serial.begin(115200);

pinMode(LED_PIN, OUTPUT);

delay(1000);

Serial.println("AT+ADDRESS=1");
delay(500);

Serial.println("AT+NETWORKID=5");
delay(500);
}

void loop() {

while (Serial.available()) {

char c = Serial.read();
receivedData += c;

if (c == '\n') {

Serial.print("Received: ");
Serial.println(receivedData);

digitalWrite(LED_PIN, HIGH);
delay(100);
digitalWrite(LED_PIN, LOW);

receivedData = "";
}
}
}

Circuit Explanation


Transmission Side

In the transmitter circuit, the TX pin of the Arduino is connected to the RX pin of the REYAX RYLR998 LoRa module through a voltage divider network. Since the Arduino Uno operates at a 5V logic level and the RYLR998 module operates at a 3.3V logic level, the voltage divider safely reduces the Arduino's output voltage to prevent damage to the LoRa module.

The transmitter Arduino sends data packets through the LoRa module, which are then transmitted wirelessly over long distances.

Receiver Side

In the receiver circuit, the TX pin of the REYAX RYLR998 module is connected directly to the RX pin of the Arduino. The Arduino can reliably detect the 3.3V logic signal transmitted by the LoRa module, so no voltage divider is required on this connection.

When a valid LoRa packet is received, the Arduino processes the incoming data and performs the desired action.




Conclusion

This project demonstrates how the REYAX RYLR998 LoRa module can be used to establish reliable long-range wireless communication without requiring Wi-Fi, GSM, or Internet connectivity.

During testing, successful communication was achieved over a distance of approximately 4 kilometers, making this solution suitable for remote monitoring, smart agriculture, industrial automation, telemetry systems, and Research & Development (R&D) applications.

I hope this project helps you understand the practical implementation of LoRa technology and inspires you to build your own long-range communication systems.

Thank you for reading this project.

Aryan Pandey

Founder – TechnoSAP

Instagram: http://instagram.com/aryanpandey699

YouTube: http://www.youtube.com/@TechnoSAP

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