cancel
Showing results for 
Search instead for 
Did you mean: 

P-Nucleo-LRWAN2 stops working on TTN

Andrew Neil
Evangelist III

Cross-post on The Things Network (TTN) forum:

https://www.thethingsnetwork.org/forum/t/st-p-nucleo-lrwan2-stopped-working

I followed the 'Getting Started' instructions:

UM2587 Getting started with the P-NUCLEO-LRWAN2 and P-NUCLEO-LRWAN3 starter packs 1.0

It was all working on Tuesday (19th).

I could see traffic in the Gateway console view, and in the Device console view:

0693W000007CKsFQAW.png 

On the I-Nucleo-LRWAN1 device, the green LED blinks each time it transmits - I could see that a new payload appeared in the Device console view corresponding to each blink.

Some time in the latter part of Wednesday (20th), I noted that the LED had stopped blinking.

Investigating on Thursday (21st), looking at TTN Console, I saw that the Gateway status was ‘Not Connected’, and there was no data in the Device view.

I tried restarting the Gateway (AT+RESET), but that made no difference.

I found TTN forum posts saying that ‘Not Connected’ could simply mean that there’s no data going through the Gateway.

So I power-cycled the I-Nucleo Device.

This did start the LED blinking again, but TTN Console views showed only Join requests - no actual data messages:

0693W000007CKw7QAG.png 

The Gateway did seem to be sending Join accepts, but the device never seemed to see them - it just carried on sending requests.

Another TTN forum post mentioned that the device message counters might be out-of-sync - so I did a ‘Reset Frame Counters’ on the Device Overview console page:

0693W000007CKzpQAG.pngThis made no difference.

A different device (WizziLab SH2050 shield, in LoRaWAN mode) was able to join & send data OK.

So I left everything powered-up for a while - and it just started working again later in the day (Thursday).

This morning (Friday, 22nd), I see that the I-Nucleo has stopped blinking again!

(the WizziLab is still working).

The kit is all as-received - no configuration changes or firmware updates (other than as described in UM2587).

As supplied, the I-Nucleo blinks the green LED (ie, transmits?) every ~ 40s.

Is this too much? Could TTN be “blacklisting�? it, or something?

Another TTN forum post said it's important to keep the Device >8 feet from the gateway (to avoid cross-talk, interference, etc).

Mine was initially under 1 foot, but moving it to >12 feet away has made no difference:

The LD2 blue LED on the Gateway NUCLEO-F746ZG board blinks shortly after each blink of the I-Nucleo green LED (also after sending from the WizziLab device).

I haven’t seen a description of exactly what this indicates, but it seems to show that the Gateway at least thinks it has sent a reply?

Is there any way to get logs/diagnostics from the Gateway to see what's going on?

Likewise for the I-Nucleo.

Any other suggestions on what's going on here, or how to debug it?

I have already requested Gateway documentation - but no replies yet:

https://community.st.com/s/question/0D53W00000VgFJeSAN/pnucleolrwan2-gateway-documentation

2 REPLIES 2
Andrew Neil
Evangelist III

Update from TTN forum:

While the I-Nucleo-LRWAN1 is in this state of not seeing Join Accepts:

0693W000007COOTQA4.pngThe Gateway is always sending its Join Accepts on 869.525, but the I-Nucleo sends its Requests on various frequencies. This is correct behaviour for the EU868 join RX2 window, which uses fixed settings

But TTN normally uses non-standard RX2 settings of SF9BW125 for non-join traffic - so could it be that the I-Nucleo is mistakenly also using SF9BW125 because it's on TTN, rather than reverting to standard for the TTN "special case" of joining?

https://www.thethingsnetwork.org/forum/t/st-p-nucleo-lrwan2-stopped-working/43127/10?u=dashcanttn

Andrew Neil
Evangelist III

The fact that the WizziLabs devices work fine suggests that the problem lies in the I-Nucleo-LRWAN1 - not the gateway, or elsewhere in the network?