Raspberry Pi + Packet Radio
I don't know much about them, but it looks like an interesting method to send/receive data and control signals out past 1 mile or several km.
The latest Raspberry Pi computers come with WiFi and Bluetooth, and now you can add even more radio options with the Adafruit Radio Bonnets! Upgrade your Raspberry Pi with an RFM69 or LoRa / LoRaWAN radio, so it can communicate over very long distances. These bonnets plug right into your Pi and give you long range wireless capabilities to remote nodes that may be battery powered. Or, you can create Internet gateways with ease.
You not only get a radio module, but also a 128x32 OLED display for status messages and three buttons you can use for creating a custom user interface or sending test messages. All of the above is supported with our Python libraries so you can send or receive LoRa/radio data with other matching modules, send data to a LoRaWAN gateway, or even set up your own single channel LoRaWAN-to-Internet gateways.
Compared to the 2.4 GHz WiFi/Bluetooth radios on the Pi already, these modules run at 433 or 900 MHz (sub-GHz). You can't send data as fast but you can send data a lot farther. These packet radios are simpler than WiFi or BLE, you don't have to associate, pair, scan, or worry about connections. All you do is send data whenever you like, and any other modules tuned to that same frequency (and, with the same encryption key) will receive. The receiver can then send a reply back. The modules do packetization, error correction and can also auto-retransmit so it's not like you have worry about everything but less power is wasted on maintaining a link or pairing.
These modules are great for use with other microcontrollers with matching radios (like say our RadioFruit Feathers), say if you want a sensor node network or transmit data over a campus or town. The trade off is you need two or more radios, with matching frequencies.
Radio Modules & Frequency Variants
These radio modules come in four variants (two modulation types and two frequencies):
- The first variant is the RFM69 Radio Bonnet. RFM69's are easiest to work with, and are well known and understood. It is available in 433MHz or 900MHz frequency ranges
- The second variant is the LoRa Radio Bonnet - an exciting and more powerful radio module, but also more expensive. It is available in 433MHz or 900MHz frequency ranges
Here are the four bonnets you can choose from. All radios are sold individually and can only talk to radios of the same part number. E.g. RFM69 900 MHz can only talk to RFM69 900 MHz, LoRa 433 MHz can only talk to LoRa 433, etc.
- RFM69 @ 433 MHz - basic packetized FSK/GFSK/MSK/GMSK/OOK radio at 433 MHz for use in Europe ITU 1 license-free ISM, or for amateur use with restrictions (check your local amateur regulations!)
- RFM69 @ 900 MHz - basic packetized FSK/GFSK/MSK/GMSK/OOK radio at 868 or 915 MHz for use in Americas ITU 2 license-free ISM, or for amateur use with restrictions (check your amateur regulations!)
- RFM9x @ 433 MHz - LoRa capable radio at 433 MHz for use in Europe ITU 1 license-free ISM, or for amateur use with restrictions (check your local amateur regulations!)
- RFM9x @ 900 MHz - LoRa capable radio at 868 or 915 MHz for use in Americas ITU 2 license-free ISM, or for amateur use with restrictions (check your local amateur regulations!)