No connection to the TTN

How to get started?
#1

Hello everybody,

This is my first time using The Things Network for a project and I am experiencing quite some trouble. I am trying to connect my Arduino Pro Mini (https://www.makerfabs.com/maduino-lora-radio-433m-868m-915m.html) to a gateway in my area (approx. 50meter) and it just doesn’t work. Since it is my first time working with the TTN, I am following tutorials to upload “Hello world !” (the code made by Matthijs Koojiman) to the TTN. By following the tutorials step by step and understanding about everything. I compiled the code and didn’t get any errors, but I am getting the following on my serial monitor :

image

And then absolutely nothing happens, I am not getting anything on my TTN account. As said above I am new to this so maybe I made a very obvious mistake but I really don’t know what it could be. I did change the frequencies, the pins, the device EUI (lsb), application EUI (lsb) and app Key (msb).

If you have any idea what I could be doing wrong please let me know, it would be very much appreciated.

Thanks in advance !!!

#2

Hello! The device is sending out a join request but not hearing anything back.

The first thing to do is to swap over to ABP as that doesn’t require your device to hear a join response.

However there is a possibility that the local gateway isn’t operating as it should or expected or even on - if you look at the map on TTNMapper.org you should get an idea of when it was last operational.

If you can look at these two first and let us know the results / detail.

1 Like
#3

This could be a problem. Your link is to a product which seems to imply that it works on all of 433, 868, and 915 MHz, yet it shows a picture of a board with what looks to be an RFM95 or smiliar module, and those do not have such frequency flexibility. Rather, they use a chip where high (868/915) and low (433) MHz energy literally comes out of distinct pins, and traditionally for high band they are manufactured with tuned circuits for one of 868 or 915. The manufacturer gives no indication of what you’ll actually receive, though I do see 915 appearing in the part number. A high/low band mixup should be expected to result in complete failure - at best, maybe a range of a meter. A mixup between the two high bands is likely to result in curtailed range, but should still work over tens and maybe even hundreds of meters absent obstructions.

At this point it would be key for you to explain:

  • In which LoRaWAN region are you operating? Failing that, which country?

  • What if any markings on your node indicate actual hardware frequency band support?

  • What exactly have you done in terms of configuring LMiC for this bandplan?

  • What exactly is your gateway? How exactly has it been configured for your LoRaWAN region?

  • What if any other indications do you have that the gateway is operating? Has it received packets that are not yours? Can you get into the gateway (serial port, SSH, web gui) and view the packet forwarder log?

#4

We swapped over to ABP, and it worked !! We used again the example code of Matthijs Koojiman except this time the ABP-version. Thank you so much for that.
But now we are only getting the “Hello world” just once on our application data and then nothing happens. When we reupload the code on our arduino, it resends it but again only once instead of every 60 seconds. Do you know what could be the reason for this ?

#6

Check all connections (DIO) and make sure the pin mappings are correct. It looks like the stack does not finish the one send/receive cycle.

1 Like
#7

Yes, you are right !! We modified the pin mapping too:

const lmic_pinmap lmic_pins = {
.nss = 10, // chip select on feather (rf95module) CS
.rxtx = LMIC_UNUSED_PIN,
.rst = 5, // reset pin
.dio = {2, 6, 7}, // assumes external jumpers [feather_lora_jumper]
}

Weirdly the pinmappping of the manufacturer of the radio was wrong.
But thank you so much, you all were really helpfull.