Wireless Lora RFM95 868MHz Ultra-long Range Transceiver

Features:

• LoRa™ long-range spread spectrum communication
• Up to 168 dB link budget for extended range
• High receiver sensitivity down to -148 dBm
• +20 dBm high-power output (100 mW)
• Supports multiple modulation types (LoRa™, FSK, GFSK, MSK, GMSK, OOK)
• Programmable data rate up to 300 kbps
• Low power consumption (RX current ~10.3 mA)
• Built-in packet engine with CRC (up to 256 bytes)
• Automatic RF Sense and Channel Activity Detection (CAD)
• Integrated temperature sensor and low battery indicator
• Excellent interference immunity and blocking performance
• Compact 16 × 16 mm form factor

Specifications:

• Frequency: 868 MHz
• Modulation: LoRa™, FSK, GFSK, MSK, GMSK, OOK
• Max Output Power: +20 dBm
• Sensitivity: Up to -148 dBm
• Max Bit Rate: 300 kbps
• Link Budget: Up to 168 dB
• RX Current: ~10.3 mA
• Dynamic Range RSSI: 127 dB
• Frequency Resolution: 61 Hz
• Packet Size: Up to 256 bytes
• Operating Voltage: 1.8V – 3.7V
• Module Size: 16 mm × 16 mm

Pinout of the Module:

The RFM95 module uses an SPI interface for communication and exposes essential control pins.

1. VCC: Power supply (1.8V – 3.7V)
2. GND: Ground
3. SCK: SPI Clock
4. MISO: SPI Data Output
5. MOSI: SPI Data Input
6. NSS: Chip Select
7. RESET: Module reset
8. DIO0–DIO5: Interrupt pins

Applications:

• Long-range IoT communication systems
• Smart metering (AMR)
• Home and building automation
• Wireless alarm and security systems
• Industrial monitoring and control
• Agriculture and irrigation systems

Circuit:

Code Example Arduino UNO and RFM95 LoRa Transceiver with Inductor for Wireless Communication

#include "SPI.h"
#include "RH_RF95.h"

// Singleton instance of the radio driver
RH_RF95 rf95;

void setup() {
  Serial.begin(9600);
  while (!Serial) ; // Wait for serial port to be available
  if (!rf95.init()) {
    Serial.println("LoRa radio init failed");
    while (1);
  }
  Serial.println("LoRa radio init OK!");
  // Set frequency
  if (!rf95.setFrequency(915.0)) {
    Serial.println("setFrequency failed");
    while (1);
  }
  // Set the power level: 1-23, 23 being the highest
  rf95.setTxPower(23, false);
}

void loop() {
  // Send a message every 3 seconds
  const char *msg = "Hello World!";
  rf95.send((uint8_t *)msg, strlen(msg));
  rf95.waitPacketSent();
  delay(3000);
}

Arduino IDE Setup (LoRa):

Install Arduino IDE:

• Download Arduino IDE

Install LoRa Library:

• Open Arduino IDE → Sketch → Include Library → Manage Libraries
• Search for "LoRa by Sandeep Mistry"
• Install the library

Upload Code:

• Select your board (Arduino / ESP32)
• Choose correct COM port
• Upload and monitor serial output

Important Notes:

• Use only 3.3V logic (not 5V tolerant)
• A proper antenna is required for operation
• 868 MHz version is region-specific (EU band)
• Ensure correct SPI wiring for stable communication

Resources:

• RFM95 Datasheet
• LoRa Library
• LoRa Technology Overview