Adding wireless communication to your Arduino projects opens up endless possibilities. This guide covers the essentials of Arduino radio modules, with a focus on Coral RF SX1262 modules—the latest generation of long‑range, low‑power LoRa technology.
A radio module lets your Arduino send and receive data wirelessly. Most modules use a simple SPI or UART interface. You don’t need to be an RF expert – the module handles modulation, encoding, and error correction for you.
Popular frequency bands include Sub‑1GHz (315/433/868/915 MHz) and 2.4 GHz. Sub‑1GHz offers longer range and less interference than the crowded 2.4 GHz band.
| Type | Typical Range | Pros | Cons |
|---|---|---|---|
| CC1101 | 500‑800 m | Cheap, good for medium range | Lower power, 3.3V only |
| SX1262 (LoRa) | 5‑15 km | Very long range, ultra‑low RX current (~4.6 mA) | Slightly higher cost |
| nRF24L01 | <100 m | Very cheap, high data rate | Short range, 2.4 GHz interference |
Why choose SX1262 over older SX127x?
SX1262 consumes about 50% less power in receive mode (4.6 mA vs 10 mA), has built‑in +22 dBm output power, and offers better sensitivity (-148 dBm).
Coral RF (Shenzhen Heyan Technology) specialises in Sub‑1GHz modules based on Semtech SX1262 and TI chips. Their modules are Arduino‑friendly, with complete example code and documentation.
Chip: Semtech SX1262
Frequency: 150–960 MHz (433/470/868/915 MHz)
Output power: +22 dBm (built‑in)
RX current: ~4.6 mA
Sleep current: <0.2 µA
Range: 5–10 km (line‑of‑sight)
Interface: SPI, 3.3V logic
Size: 16×16 mm
Perfect for battery‑powered IoT sensors, smart metering, and general long‑range telemetry.
Output power: +33 dBm (2W) with external PA/LNA
Range: Up to 15 km+
Supply: 3.3–5V (works with 5V Arduinos)
Size: 36×24 mm
Ideal for drone control, long‑range monitoring, and applications that need maximum reach.
Wiring (N401AS to Arduino Uno – use level shifters for 5V boards!) :
| Module Pin | Arduino Uno (3.3V) |
|---|---|
| 3.3V | 3.3V |
| GND | GND |
| MOSI | 11 |
| MISO | 12 |
| SCK | 13 |
| NSS (CS) | 10 |
| BUSY | 8 (required) |
| NRST (RST) | 9 (optional) |
Important: SX1262 uses 3.3V logic. For 5V Arduinos, use a logic level converter on all SPI lines. The BUSY pin must be connected.
The easiest way to start is with the RadioLib library (install via Library Manager).
| Need | Recommended |
|---|---|
| Battery‑powered sensor (5‑10 km) | N401AS |
| Extreme range (15 km+) | N427AS (2W) |
| Plug‑and‑play testing | Coral RF USB dongle |
| EU operation | 868 MHz version |
| US operation | 915 MHz version |
Use the lowest data rate (e.g., SF12)
Set output power to +22 dBm (or +33 dBm on N427AS)
Use a good antenna tuned to your frequency
Keep modules elevated and away from metal
Coral RF official website: www.coralradio.com
Email: info@coralradio.com
Coral RF’s SX1262 modules offer a modern, power‑efficient way to add long‑range wireless to Arduino projects. The N401AS is great for most battery‑powered IoT applications (5‑10 km), while the N427AS delivers 15 km+ when you need extreme reach. With simple SPI wiring and the RadioLib library, you can have a working LoRa link in minutes.