WiFi LoRa 32 V2 cannot join single-channel gateway for TTN

I am using these devices:

I am using these settings:

  • US915 frequency band, userChannelsMask[6] = { 0x00FF, 0x0000, … 0x0000}
  • Semtech single channel packet forwarder software, global_config.json = " “SX127x_conf”: {
    “freq”: 905100000, … "

The TTN frequency plan is here: https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html

The Heltec frequency plan is inhere:

I am using the latest Heltec Arduino library and framework.


The Heltec library never uses frequency 905100000Hz, even when userChannelsMask[0] = 0x00FF. 905100000Hz is userChannelsMask[0] = 0x0400, right?

How can I connect to my gateway at 905100000Hz?


please refer the picture.

Hi Jason,

Thanks for this. I seems that 905.1MHz is channel 14 (channels[13])? So if I set userChannelsMask = {0x2000 …}, the LoRa node should attempt to join the LoRaWAN gateway on the 905.1MHz channel.

Is this correct?

My major goal is to get these LoRa nodes to join a 1-channel LoRa gateway. I am having a lot of problems.



it should be 904.9MHz

TTN does not support single channel gateways in anyway, they should not be used as it causes lots of issues for others

Hi Jason, does this mean that channels[14] is 905.1MHz? How do I force TX on 905.1MHz channel?

@jezd, I don’t understand - TTN offers a single-channel gateway as a choice during gateway creation on the TTN website. My gateway seems to be connecting just fine to their service, just not the nodes. Also there is no documentation saying single-channel gateways are not allowed or compatible with TTN.

Can you provide some evidence TTN does not support single-channel gateways in any way?

See here >> https://www.thethingsnetwork.org/forum/t/no-access-to-10-130-1-1-anymore/42456/6

There are various posts on the TTN forum, TTN is moving to V3 soon and I am 99% sure it will not support them full stop, they cause too many issues and are not compliant.

Single channel gateway by there very design are tuned for the owners needs, on this alone it goes against everything the public TTN stands for, ie standards, open and shared

By all mean pop over the TTN forum and ask the question

Manufacturers are advised not to advertise single channel gateways as being TTN compliant too - they are not

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Hey @jezd, thanks for the forum link and thorough explanation - much appreciated. I’ll check it out.

I understand TTN’s goals and reasons for shunning 1-channel networks, right now I’m building a proof of concept system that would benefit from the ability to update node firmware among other things. I think the open TTN network won’t allow that much data passing through it, thus my desire to host a private network.

Is a private LoRaWAN + TTN arrangement the right approach?


Proof of concept sure but remember your missing our on all the reasons/benefits of what a full lorawan compliant devices is - basically your doing lora point to point in essence. Data volume on a public network is low, that should not worry you - keep in mind the broadcasting activity will not be lessoned by you keeping your set up private, other devices will still be operating etc, also you lose out on your devices having there signals routed via other public TTN gateways.