Receive Data

[Famosi]

LoRaWan communications.

How to receive data instead of send? In the examples folder there are examples about how to send data from a device to a server. But how to handle data received from a server? In particular I’m sending data through the helium console “downlink” tool.

[beegee-tokyo]

Hi,

In the LoRaWAN examples you receive the data in the callbacks for RX, e.g. in the LoRaWAN_OTAA_ABP example it is in

void lorawan_rx_handler(lmh_app_data_t *app_data)
{
  Serial.printf("LoRa Packet received on port %d, size:%d, rssi:%d, snr:%d, data:%s\n",
          app_data->port, app_data->buffsize, app_data->rssi, app_data->snr, app_data->buffer);
}

In LoRaWAN are three node classes:

• Class A (lowest power consumption) - the node receives downlink packets from the Helium Console only after he has sent an uplink packet to the Helium Console
• Class B - not supported
• Class C - (highest power consumption) - the node is always in RX mode and the downlink packets from the Helium Console are received immediately

But Class C is not supported by the Helium Console (at least I cannot find how to set it).

So you receive a downlink packet from Helium Console only after the the RAK4631 node has sent an uplink packet. You set the node class in the lmh_init(&g_lora_callbacks, g_lora_param_init, doOTAA, g_CurrentClass, g_CurrentRegion); call. The forth parameter g_CurrentClass sets the node class. Default is Class A. If you want to change to Class C, you have to do on both the node and in the Helium Console

[Famosi]

Hi @beegee-tokyo thank you so much for the fast response! :smile: I will let you know if I manage to set a Class C node on the helium console.

If it's possible I have another question for you. I put it here but let me know if it would be better to open a new Issue.

I'm using this example to implement a GPS Tracker but without using the 3AXIS sensor. Everything works fine but I have two problems:

1. When I upload a new version of the code to the RAK4631 it takes too much time to localize itself. Sometimes 1 hour, sometimes 3 hours, sometime 6 hours. Is it normal? Can you explain me why it takes so long or how to fix it?
2. The RAK4632, when localized, send a packet every 20 seconds. However when I move the RAK (e.g driving around the city) the position is updated rarely (like every minute). What i mean is that for 1 minute sends always the same [LAT,LONG] coordinates.

Thanks again for your time. Really appreciate your work!

[beegee-tokyo]

@Famosi

Where are you testing the GPS tracker example code? I am getting a location fix within 12 to 30 seconds when outside of the building. Inside the house I never get a location fix when the device is on my table. Moving it to a (not tinted) window, I can get a location fix within ~40 seconds.

Sending every 20 seconds, when moving is too fast in my opinion.

And last question, how is your GPS antenna located? The antenna has a white sticker on one side. This side should be oriented towards the sky to get a fast location fix.

[Famosi]

I was testing it on my table (indoor).... that's should be the reason! :smiling_face_with_tear: Now outside the window it takes about 1 min. I didn't test it cause I didn't have a 3V battery to move it outside.

I think you can close this issue, hope it helps someone else. Thank you for your time!

[beegee-tokyo]

Will close this now. If you have more questions, you can open a new issue here or (better, because more people can support) open it on our Forum