How to connect Adafruit Feather 32u4 LoRa to TTN?

End Devices (Nodes) Hardware
21

Do you recommend the MCCI library?

22

Not really relevant to your hardware - you have a LoRaWAN module that does all the work that LMIC would do.

1 Like
23

Other way around. Theyā€™re trying to use software for the RN module, but their Adafruit board has a bare radio

24

Doh! :roll_eyes:

In that case, @arlx07, you should use MCC LMIC to be found on GitHub and as thatā€™s flying without the safety net of LMIC-node, you need to go through the instructions line by line.

Or replace the device with an Adafruit Feather M0 RFM95 which is directly supported by both LMIC & LMIC-node.

26

@arlx07 It looks like you are wasting our time!

You were already advised to read the instructions in the Big LoRa32u4 boards topic.

Instead of following the instructions in that topic you tried to run other, unsuitable software for your board (for RNxxxx module which your module does not have).
Then you come back and ask for help because you donā€™t get that working, confusing other users with errors about RN module. And now you are asking if we recommend the ā€˜MCCI libraryā€™ā€¦

YES! and this was/is already documented at the start of the Big LoRa32u4 boards topic.

With the current TTS CE V3 (aka TTN V3) network you do not have (many) other options than using the MCCI LMIC library with your board.

1 Like
27

Where can I find APPEUI, DEVEUI, APPKEY for the adafruit feather 32u4 868MHz boards?

28

When you register the node on the Console, under you application, it can create you one.

29

I know this is an old thread, but I recently got two Adafruit Feather 32u4 US915 boards. Also this is my first experience with LoRa and TTN. And also C++.

Iā€™ve been able to make them talk to each other with some TX/RX sketches, but I am having a heckuva time trying to get it to work with the mcci-catena/arduino-lmic library.

Also Iā€™m a bit of a noob and Iā€™m not sure Iā€™m using the sketch properly.

At least, I am confident that Iā€™m not getting anything out of the radio when i run that ttn-otaa-feather-us915.ino file.

Iā€™ve put in my keys for eveui, appeui, and appkey, but I dont think that would have to do with nothing coming out of the radio.

I do have a connection going from pin 6 and DIO1.

At the top of ttn_otaa_feather_us915.ino, i have added

#define ARDUINO_AVR_FEATHER32U4 1

Iā€™m not 100% sure what the right way to do this is. Its been a long time since Iā€™ve done much with C++.

On the serial monitor in the arduino ide, I get:

Starting
Packet queued
315705: EV_JOINING
316285: EV_TXSTART

My dad is a ham, and he used one of his receivers to listen to 915MHz, and he didnā€™t hear anything.

He DID hear something when I tried the TX/RX demo programs before.

Its just, when I try to use that lmic.h library, nothing happens.

Regardless of whether or not I can hit a TTN node (theres supposed to be one very close to me), at least i would like to confirm some traffic leaving the radio.

Is this worth putting a ton of time into or should I go with a different board with better software support?

Thanks!

-Travis

30

Yes, if only because it takes Ninja level LMIC skills to get it in to an ATmega328P aka Uno, Iā€™m not even sure how you got it in to a ATmega32u4 which has even less flash.

However you also have some gaps in knowledge to resolve - devices donā€™t talk to each other, they transmit, are heard by gateways in range which relay the uplink to the LoRaWAN servers, process it and pass that message on to your end point / integration.

Other (smaller) libraries are available that do enable individual devices to talk to each other, known as point to point, but this is the TTI funded TTN LoRaWAN forum so is not discussed or supported here.

The other fallacy to address is using ā€œOther Peoples Gatewaysā€. Yes, the TTN is about communal use of each others gateways, but that only works if they are in range and the discussion of range has already been covered this week for you to read - there are many variables but mostly when developing devices owning your own gateway is somewhat essential as you can control coverage and debug device transmissions. The US915 band covers 902.3 - 914.9MHz with the device randomly choosing channels on each transmission and the nature of LoRa spread spectrum chirps need some prior understanding to be able ā€˜hearā€™.

Most of the Arduino C is pretty basic - as in no more than BASIC or Python or PHP or Java. Early days itā€™s mostly about having the right kit, following the instructions and reading the Learn section (linked top of this page).

A more straightforward system is LMIC-node to start with and that has a list of boards that are known to work with it. To recommend a specific board it always helps to know what your end goal is.

31

Thank you so much for the response!

Yes, if only because it takes Ninja level LMIC skills to get it in to an ATmega328P aka Uno, Iā€™m not even sure how you got it in to a ATmega32u4 which has even less flash.

I guess in its current state its still small enough to fit? Or at least the bits of it Iā€™m trying to use. In the output during the upload, it does come pretty close to filling it up completely.

However you also have some gaps in knowledge to resolve - devices donā€™t talk to each other, they transmit, are heard by gateways in range which relay the uplink to the LoRaWAN servers, process it and pass that message on to your end point / integration.
Other (smaller) libraries are available that do enable individual devices to talk to each other, known as point to point, but this is the TTI funded TTN LoRaWAN forum so is not discussed or supported here.

Yes, using other libraries like here Using the RFM9X Radio | Adafruit Feather 32u4 with LoRa Radio Module | Adafruit Learning System, I have confirmed that the two boards do have functional radios.

With regard to gateways, Iā€™ve been window shopping those pretty hard. I donā€™t have an outdoor requirement for a gateway, so Iā€™ve been looking at

  • TTN Indoor Gateway
  • HT-M7603 Indoor LoRa Gateway ā€“ Heltec Automation
  • Raspberry Pi LoRaWAN Module SX1302 SX1303 Mini PCIe 868M 915M Lora Gateway Hat Expansion Board (from waveshare)
  • your fav gateway here

As far as an ā€˜end goalā€™, Iā€™m not really sure yet. Currently a solution in need of a problem. But at least making something hit TTN properly would definitely be an accomplishment.

If not these Adafruit 32u4 things, what do you suggest? Lots of interesting hardware from LILYGO (especially that T-Deck). Also Heltec and Waveshare. I just got the Adafruit boards because they were on the rack at my local MicroCenter.

Curious for non-ESP32 things, as youtuber celebrity Andreas Spiess has some complaints about how the ESP32 behaves when it wakes from sleep. Though its not a deal breaker if thatā€™s the best platform to develop on right now.

Thanks and hope youā€™re having a great day!

-Travis

32

A ā€˜no sensorā€™ out-the-box sketch usually just about fits but as soon as you add something it grows quickly. You need to also ensure you have at least 900 bytes of free RAM.

This:

And if you search the forum, youā€™ll understand why.

Given our propensity for battery powered devices, ESP32 is rarely the best platform to develop on. Which circles back to using the forum, the Learn section and the LMIC-node info to cross reference your lists to see what is recommended & how people get on with them.

2 Likes
33

To me LMIC is a beast that I canā€™t tame. In my testing it seems that latest LMIC is too big for feather-32u4. I had LMIC mismatch probably due to a memory corruption. I have success with feather-32u4 (deep sleep) and SlimLoRa + GPS + IMU + EEPROM. Even with power down the device does not need to rejoin. But I didnā€™t added support for US915. You can try, adapt and submit PR (pull request) to add support for US915.

I think the official name us US902. I didnā€™t tested the freqs. Maybe itā€™s working out-of-the-box.