WiFi, Bluetooth, ZigBee and Cellular are everyday wireless protocols you use every day - at home, at work, with friends. Sometimes, though, you need to leave the well-known and venture to the more exotic! The RFM69 and LoRa Feathers let you create a more flexible wireless network.
Instead of depending on a WiFi router, Bluetooth Central, ZigBee Master or Cellphone tower, LoRa and RFM69 work well in point-to-point or meshing configurations, with eye-popping ranges. They also don't need complex pairing or connection overhead, turn on the radio and transmit when you like, then turn it back off. They are the "rugged individuals" of wireless!
The trade-off is that you'll have to do a bit more work in the software to manage your packets, and re-transmission.
- No need for master or central router, you can use two radios or hundreds of radios, all talking to each other
- Long range: RFM69 can go 500 meters with a basic antenna, 5Km with directional antennas and care. LoRa can go 2Km with a basic antenna, 20Km with directional antennas. (Contrast with ZigBee & WiFi's ~100m max range, and BT ~10m range)
- Great for short burst packets, with ~10Kbps rate
- Best for outdoor usage
- RFM69 have low cost, LoRa are more expensive (but with longer range)
- Adjustable transmission power
- No link overhead, send packets without needing setup/teardown of connection
- RFM69 has built-in encryption capability
- Neither RFM69 nor LoRa are standardized, or built into laptops, so you need at least two of the radios to connect to a computer
- LoRa Feathers do not have LoRaWAN built in, must be added in software (which isn't hard)
- Link management and re-transmission is up to the user, so there's a little more work to do!
- LoRa radio does not have built-in encryption, must be added by hand by the user.
- Not good for audio/photo or video bandwidths, best for small data packets.
- Tweaking and tuning of antenna setup required to get the longest ranges.
There's a lot of options for these radio feathers, because each chipset (32u4 and M0) has two radio types (RFM69 and LoRa) and then two frequencies (433MHz and 900MHz). That's 8 total options.
The easiest decision is what frequency you need to use. If you are in ITU "Americas" you should go with the 900MHz radio. If you are in ITU "Europe" you should go with 433MHz radio. (If you are a HAM radio licensed operator you may be able to use either, check your countries' available frequency bands, and restrictions)
If you are in a country that allows unlicensed usage of 868 MHz, pick the 900 MHz radio. Both RFM69 and LoRa are 'software tuned' - so just make sure you set the Arduino library code to 868 MHz when you upload it.
You can tell what frequency your radio is by the dot on top. Red dot means ~400 MHz, Green dot means ~900 MHz.
Then pick your radio type. The lower cost RFM69 doesn't go as far but has a lot of functionality and can do the job for most projects. LoRa has much better range, and can be used with LoRaWAN, but has additional cost. You cannot mix and match radios: RFM69 cannot 'speak' LoRa.
Both radio modules are identical shape and pinout, so we re-use the same Feather layout for both.
Finally, pick your chipset. ATmega32u4 is a well known 8-bit AVR processor, and may be more familiar to people who use the similar Arduino '328s. The ATSAMD21 M0 is a 32-bit Cortex M0, with a ton more flash and RAM, and is also supported in Arduino but is a little newer and so does not have as many years of projects and example code already. If you want to use LoRaWAN firmware, we suggest M0 Feathers since you will need to store all that extra software