RAK4600 (nRF52832+SX1276 LoraWan Chip) last resort GW via bluetooth

[mvcorrea]

Looking around to develop hardware/software using the RAK4600 module!

RAK4600 (lora Node) uses Lora as its main way to communicate with my Lora server (normal flow).

Consider the hardware (lora node) will be almost always near a cell phone!

The question is if is it feasible use the nrf52 (backup flow) as a backup to connect to a lora server when lora is unavailable ?

Any suggestions/examples are welcome.

[Edvin]

Hello,

That may be. Does the Lora node support  BLE? To be honest I am not sure I understand the use case. The nRF52 supports BLE. 

What sort of device is the Lora node? The nRF can communicate with a Cell phone over BLE. The rest is something you would have to set up.

BR,
Edvin

[mvcorrea]

Hi Edvin, thanks for your prompt response.

Explaining the topology in a better way.

The RAK4600 module (lora node) consists in the nrf52832 and a lora chip (?SPI connected?), and a few more sensors!

The Lora Gateway is a mikrotik wAp LR9 kit.

The Lora Server is a server running ChirpStack LoraWan Network Server.

I "think" the required is:

- the cellphone connects to RAK4600 (nrf52) and receive the flow of lora messages (~50bytes long)

- the phone encapsulates the message(s) in a tcp/ip package and forward it to the lora server.

I don't know how it works but I suppose I need a daemon/service running on the cellphone waiting for the "bounced" messages! If they appear forward them. So coding is needed on the "nrf52" and on the cellphone "daemon/service".

feasible? any suggestion?

thanks,

Marcelo

[Edvin]

Still not entirely sure that I understand the use case, but you can use BLE to send messages from the nRF52 to the phone. In what cases you would send this messages is up to the application logic, so you would need to decide that. E.g. how to find out that a message is not in the cloud -> signal the nRF52 -> nRF52 receives signal -> BLE -> phone -> upload to cloud.

I can help you with the nRF52 receives signal -> BLE part, and how to receive the signal (pin / UART / SPI / whatever protocol you use). The rest of the logic from the LORA chip or on the cloud side of the phone is not my field of expertise. 

Best regards,

Edvin

[mvcorrea]

HI there,

let me try another approach, because I am lost. Of course I need to read more about ble :)

lets suppose one way communication! Node to Server (thru cell phone)

- Can I initiate communication from node to cell phone (phone listening for connections)?

- Can I remove the payload from the bluetooth frame attach to an http POST request and call a REST API?

the payload is 50 bytes MAX in length, I could implement a queue and call the rest api in once in a minute.

at the beginning its all I intent.

I am in void here, any sample code implementing any of this?

[mvcorrea]

Hi there, thanks again.

Sorry but I am a little confused here.

the nrf will be connected with some spi sensors (eventually a gps via UART).

and sending updated data via lora radio (lets suppose the lora part is already working "data arriving on the lora server").

When a lora gateway is not available I need to route those bytes thru the cell phone in order to reach the lora server.

Having the bluetooth payload on the phone I just need to call an REST API with it.

sorry if I am still not clear enough!