The TTN gateway generates Join accepts in this case.
The software I run on both identical ESP32’s is identical and I bought both of the at exactly the same time. I even swapped the node
What confuses me is that I fiddled with the antenna and suddenly it worked.
Sounds like a timing problem
Attempting to do meaningful comparisons at such short distances is very difficult and prone to error.
Perhaps if the Gateway was in an anechoic chamber or out of doors in a large open area with no nearby objects, and the two nodes antennas were at the exact same height and angle, you might get some form of consistent result …
Your problem is exemplary, related to defective materials: board, antenna and/or antenna cable. The issue is not specifically related to OTAA. It will impact ABP down-link messages just as well. Latter you seem not to have tested.
The issue is not OTAA specific, therefore ‘people new to OTAA’ makes no sense here.
(And lack of experience would be better expressed as ‘new to LoRaWAN’ than as ‘new to OTAA’.)
Like @cslorabox already mentioned the observations described are usually caused by timing issues (in software). Defective hardware (and poor antenna connections) can cause different kinds of problems but are not representative for OTAA issues.
@bluejedi I am with you.
but today it was crazy I have nothing done with my node. No change in software no change in position of antenna and even I didn’t get a join. I just had the node off some day. Ten minutes later a get suddenly a join with no problem at all. And also it worked several times later.
Probably time to modify the node firmware to blip a GPIO on transmit and receive and start looking at the timing with a scope or logic analyzer.
Also review the issues list for whatever firmware you are using.
I am testing at the moment the heltec cubecell with arduino support. And modify firmware is not so easy here and hobiest as I am are have no Oscilloscope at home. In my company I have a 1.5 GHz Oscilloscope a spectrum and a network anyliser so all needed to see the UhF transmission. But no time to do this at work.
So I have just the option to hope my hardware is good enough. And the provided lorawan library is good. So I can understand when people are frustrated.
I was it also if it doesn’t work because I have nothing changed in firmware of the node just connect power. Last day it worked. Suddenly not. Ten minutes without power it worked again. No change in hardware and software.
So even sometimes luck when it is working.
It’s only random so long as you don’t consider the actual causes.
A cheap $10 USB based logic analyzer works too, you don’t need a scope.
Just tried the new Heltec module I received today with the exact same code and it just works now.
@MOS-FET Same problem here too. I got a couple of the Heltec Cubecell’s, I fired it up with the sample code, set it to 915mhz, and it just worked and thought it was amazingly simple. Then 19hours later it just stopped… I saw a couple partial joins, then it’s never joined again. I pulled out the 2nd one, known good 900mhz antenna, same issue. It’s really discouraging. My other nodes are working fine, so I suspect my gateway is running fine.
EDIT: Yes I tried different pigtails and moving between 3 - 20m from the gateway.
@noebl1 ok. Which of cubecell you are using I used the capsulate one. I think they have problem in receiving. Because the join in my case was always accepted from my Gateway.
I have written an issue on GitHub to this matter.
Thanks for your answer. I have an TTIG indoor Gateway. I will do more test next day’s if I have time. Because the electrical node specs and low power are quite super.
@cslorabox can u suggest an logic anylizer.
Is there a way with TTNv2 to
@MOS-FET They are both the CubecCell dev boards.
I had wondered if for some reason there was an issue on the TTN side (I figured a remote chance, even though unlikely), so created a new application with a new app key and same issue. I’ll post to the Heltec forum as well for some ideas.
Apparently somehow depending on the type of gateway, or on the type of forwarder software (like Semtech UDP or TTN MQTT), the gateway Traffic page(s) might show an orange Join Request. The application’s and device’s Data page will always show an orange Activation if TTN accepted the Join Request (including the new DevAddr). And the Traffic page of the gateway that was selected for the downlink will show the green Join Accept:
For errors see OTAA shows "Activation DevNonce not valid: already used" or Activation not valid - no gateways available.
I just retried my first Heltec Lora esp32 V2 node now that I have 2 other Heltec nodes working and everything points to a defective board. It transmits but it has a hard time to receive. Sometimes it does but most of the times only when it goes to SF9
Which library are you using? LMIC?
I had this kind of problem with older Heltec (v1) boards, too. I assume root cause is a timing issue due to the onboard oscillator.
@obaeyens Whenever I have joining problems, 9 out of 10 times it is my local network for some reason messing up the incoming traffic, so my gateway never transmits the join accept message that is in fact send from the TTN backend.
For around 10 dollars on Ali you can buy a USB stick spectrum analyzer that makes an incredibly helpful tool, because it makes visible the transmissions of your node AND the replies of your gateway, so you can troubleshoot much faster.
This one:
“IBM_LMIC_framework” (arduino-lmic-master)
