Can't recieve data in LoRa mode

[ThatStudentGuy]

I just started experimenting with the LoPy.
My first step is to use a LoPy as just a receiver for any traffic sent with LoRa and fetch the incoming data. I have very little knowledge of radio itself and i put my trust towards the board to handle most of the radio technology.

I followed the gateway code example of LoRa nano-gateway found at https://docs.pycom.io/pycom_esp32/pycom_esp32/tutorial/includes/lora-nano-gateway.html. To my understanding this should be able to pick up any kind of data sent from a LoRa device. Currently my LoPy is only picking up the following output: b". The board has been tried with LoRaWAN activated towards The Things Network and can receive packets - somewhat scrambled but consistent.
In the example code i can't see any specific settings used for channels, preamble, sf etc and thus conclude that specific settings are not needed?

To reiterate, i don't intend to use the node code provided in the example only the gateway code to fetch any data being sent.

Do any of you have any suggestions of what might be the problem? Am i missing something fundamental?

Thankful for any help!

[jmarcelino]

@ThatStudentGuy
Yes, that's right, if you want to communicate between LoPy boards use "raw" LoRa ( mode=LoRa.LORA ) and set the boards up with the same parameters in LoRa.init(...)

If you want the LoPy to participate in LoRaWAN networks (with a real gateway like the Kerlink) then use mode=LoRa.LORAWAN which doesn't have parameters, those are defined by the region you're in.

LoPy as a pseudo-LoRaWAN single channel gateway is coming but it is a bit of a hack more for development and internal testing where users are aware of the limitations and shouldn't be a replacement for a real LoRaWAN gateway.

[bmarkus]

@ThatStudentGuy said in Can't recieve data in LoRa mode:

@jmarcelino Thank you for the answer. I'm a bit familiar with the LoRaWAN protocol and how it works. Okay so if i understand it correctly, the LoPy can basically only speak to other LoPy's that are pre-configured with the same init() parameters? For my testing and experimenting purpose that will probably suffice.

For direct communication between devices built on SX27xx modems, like LoPy all must use the same frequency and SF

[ThatStudentGuy]

@jmarcelino Thank you for the answer. I'm a bit familiar with the LoRaWAN protocol and how it works. Okay so if i understand it correctly, the LoPy can basically only speak to other LoPy's that are pre-configured with the same init() parameters? For my testing and experimenting purpose that will probably suffice.
After reading most of the forum i understand that there is "real" nano-gateway implementation in the pipeline. My intention was to make a workaround and work with raw LoRa and maybe just add basic LoRaWAN functionallity to the gateway as needed until further updates and therefore needed to know the limits of the LoPy LoRa raw mode.

[jmarcelino]

@ThatStudentGuy
Though both operate using a LoRa radio signal, the nodes around you actually follow the LoRaWAN specification which is a more complex protocol with a very different payload from the simple one implemented in the nano-gateway example.

The LoRaWAN spec also implies that nodes are able to transmit using a range of radio frequencies and spreading factors, which is fine for a gateway like the Kerlink to pick up, but the nano-gateway can only listen on one (in the example these are set by the defaults on LoRa.init()).

There is work in progress to extend the nano-gateway code to work with LoRaWAN packets, but in any case it'll still have to live within the restrictions of a single channel and spreading factor.

[ThatStudentGuy]

@jmarcelino
Should have described that part better. I'm only using one LoPy with the nano gateway code. The sending nodes are various nodes scattered around in the area. I can see that they are sending because there is a Kerlink Wirnet in the same space as the LoPy picking up data.

[jmarcelino]

@ThatStudentGuy
Can you explain your setup a bit better?

I undestand you have the LoPy running the nano-gateway script, but what device is acting as a node? Another LoPy - and if so what script is.it running - or something else?