RFM69HCW Transceiver Radio Breakout - 433 MHz - 3V3 - Packet Radio

Transfert data over a long distance from 500m to 5 Km with a RFM69HCW 433 MHz radio module

Variant of RadioFruit RFM69HCW 433 MHz restricted to 3.3V max.

I've always been fascinated by the ability to transport data over long distances using the RFM69HCW module (also known as RadioFruit at Adafruit). This module is super easy to use thanks to the easy-to-use Arduino, MicroPython, and CircuitPython libraries.

There are communication alternatives such as WiFi and Bluetooth, but these require significant resources and are intended for exchanges with computers over a relatively short distance with high data rate (which is possible thanks to 2.4 GHz radio frequency, more oscillations per second = more information shipped per second).

An RFM69HCW module will allow data to be transported over a distance of around a kilometer (between 500m and 5Km depending on the conditions). The radio frequency being around 433 MHz, the bit rate will not allow video (or even sound) to be sent but will perfectly handle data transport at a moderate rate. This lowering of the frequency also comes with advantages such as a significantly greater transmission distance and better penetration of radio waves (less sensitive to obstacles).

The 433 MHz or 868 MHz frequency ranges can be used with packet radio to efficiently transmit data over long distances (please refer to local legislation). Packet radio offers a transmission mode "similar" to Ethernet networking... understand: with error correction, re-sending, collision detection mechanisms.

RFM69 (packet radio) transmissions are simpler than WiFi or Bluetooth Low Energy (BLE). With packet radio, you can transmit data in the air without worrying about pairing or WiFi connection. All other modules listening on the same frequency (and using the same encryption key) can receive the message. Subsequently, the receiver can send a response. No need here to scan networks, pair with the phone or configure the WiFi connection beforehand.
This experimental module is, as you can imagine, more in the HAM domain since we transmit data over the radio wave. The HAM knows how to use these frequencies in compliance with the legislation so do not hesitate to contact your local HAM club if you do not have this know-how.

The breakout board is equipped with a specialized circuit that handles packet processing, auto-retransmission and error correction.
This breakout works perfectly with microcontrollers in 3.3V logic (exclusively 3.3V), it can be used to collect data in the neighborhood or in the city. The constraint with such modules is that at least two 2 breakouts are needed to establish a link but you can use more breakouts. Communication is established only if the modules are configured on the same frequency and they use the same encryption key.

The packet radio modules exists in 4 flavours:

• 2 types of modulation: RFM69 & LoRa
• 2 frequencies: 433 Mhz & 900 Mhz

The RFM69 modules are the most simple to use. The RFM69 is well known and well understood (LoRa is more powerful but also more expensive).

Features

This product is RFM69HCW at 433 MHz frequency! Packet radios module +20dBm FSK modulation including nice extras like encryption and auto-retransmit. With a simple wire antenna, this module can reach at least 500 meters (in clear view area), by using a directional antennas (and tweakings the settings), it should be possible to reach 5 km.

• Breakout based on SX1231 (SPI interface)
• +13 dBm to +20 dBm (up to 100 mW Power Output Capability, power selectable by software)
• Transmission current: 50mA @ +13 dBm, 150mA @ +20dBm
• Listening current: ~30mA (active listening)
• Range of approx. 500 meters to 5 Km. Depending on obstructions, frequency, antenna and power output.
• Allow to create multipoint networks with individual node addresses
• Encryption: packet encrypted with AES128
• Ready-to-go Arduino, MicroPython libraries
• Antenna: use a simple wire antenna. Allows to solder a µFL or SMA radio connector

Uses the amateur or license-free ISM band (ITU "Europe" license-free ISM)

Technical information

• Size: 25.3mm x 29.3mm x 3.5mm
• Weight: 3.4g
• RFM69HCW Datasheet (inclus SX1231 datasheet)