ok, you made me curious, so I've setup a Helium account and was able to join with a COMX.LoRaWAN868 module using a couple of AT commands. Unfortunately the COMX.LoRaWAN868 module has a different AT command set than the Atom DTU LoRaWAN base so the AT commands I used won't help you much. Also the COMX.LoRaWAN868 module is not covered in UiFlow which means I had to send the AT commands using the UART blocks. Essentially I had to choose LoRaWAN, OTAA, set DevEui, AppEui and AppKey (all three copied verbatim from the Helium Console) and then issue a Join command.

However what I can share is the output of the COMX.LoRaWAN868 module when I switch it over to LoRaWAN mode:

Copyright @2019-2020 Heltec Automation.All rights reserved.
AT Rev 1.3
+AutoLPM=0
+LORAWAN=1
+KeepNet=0
+OTAA=1
+Class=A
+ADR=1
+IsTxConfirmed=1
+AppPort=2
+DutyCycle=15000
+ConfirmedNbTrials=4
+ChMask=0000000000000000000000FF
+DevEui=0123456789012345
+AppEui=0123456789012345
+AppKey=01234567890123450123456789012345

From that I think you might want to try a different class (A instead of C) and a different channel mask (0xFF instead of 1).

Thanks
Felix

I have some experience with TTN though.

Hi Felix,
There are a number of gateways nearby, Helium is very similar to TTN in terms of providing all the gateway info in their interface: Console 2.

this could be a question of tweaking channel values, data rates... Unfortunately i am don't know what documentation to read so i can learn what to do, any help is appreciated.

I have never used the Helium network. I have some experience with TTN though. In case of TTN a LoRaWAN device connects to a TTN LoRaWAN gateway which in turn talks to the TTN backend. The hierarchy is probably similar for the Helium network. Have you verified a suitable Helium LoRaWAN gateway is close by?

Thanks
Felix