Heltec LoRa WiFi v4 not ever seen

Long story short I had a working v3 Heltec board on TTN that I fried. I thought I’d upgrade to the latest v4. I’m using the exact same configuration but no matter what I do, there’s no reply ever from the Gateways. Nothing shows in Live Data. Board says Tx sent but Rx always times out.

The LoRa RF functionality must work because Meshtastic runs fine. But when I flash with Arduino / ESP32 / Heltec firmware, I get serial traces suggesting the LoRaWAN join sequence goes well, but nothing reaches TTN.

I’m on US915 (in the US obviously)
Checked DevEUI, AppEUI, JoinEUI a billion times
Using Heltec’s own LoRaWan_APP.h

Has anyone here ever been able to connect a Heltec v4 to TTN?

Perhaps take a look at this message which refers to issues with the Heltec V4 modules.

Thanks Jac, much appreciated. Reading it now, I’ll see if it helps. The initial topic isn’t about Heltec v4 and the first ~20 messages don’t mention it so I had discarded the thread. I’ll read and summarize the relevant parts re/ Heltec here for future users.

As the developer of LoRaWAN for RadioLib and owner of a v4 I guess I’ll bump it up my to-do list to add support for using a PA with a proper example for the v4’s FEM pins. But I totally dislike doing it because I totally dislike this new product line, with that phrasing being an understatement.

(Nothing personal - it’s personal with Heltec instead.)

Hi Steven, thanks for your work on LoRaWAN + RadioLib. I have no loyalty to Heltec but found their v3 board excellent (in that: it worked). I guess what you’re saying is the PA functionality of the v4 breaks all the existing libraries (including Heltec’s and RadioLib’s) and short of me doing the work you’re describing (with my month-long experience with LoRaWAN and Heltec), there’s little hope for me and I should go back to either Heltec’s V3 or a better alternative (if you have recommendation I’m interested, I like native solar support from the V4).

I know, that is where the search should help you. There are just too many messages on this board to find what you are looking for by reading all of them.

The v3-line and all related are amazing, love them to pieces, have more than 100 boards across all projects. With the only thing missing being proper solar support.
But the way Heltec does the PA stuff in the new v4 line is crazy from a software/hardware view. Maybe there is some sense in the RF but that’s Dark Art for me.

The problem with the v4 is both that you need to handle the pin switching which is absolutely non-trivial at first sight, and that any existing library is unaware of the existence of this PA and blasts away at an additional 12dB of which the network server is unaware, and as a result breaking RF laws in many parts of the world.

Excuse if it’s a very naive question but is there a way to disable the PA / prevent the +12dB using current libraries? If not I’ll just go back to v3 and wait for Heltec to get their act together

For those with a short attention span / unable to search within their browser - hint SpecialKey-F / forum search / scroll etc:

Why? I know you like self-flagellation like this, but Heltec don’t deserve this. And they never sent me one to try out.

We absolutely love the v3 - it was the primary test platform for getting RadioLib to basic LW. But Heltec released v4 without any code and didn’t send anyone who knows stuff a board to figure stuff out, despite asking us what we wanted to see in a v4 product.

Yeah, it’s called amping up the Meshtastic :ox: :poop: to the absolute max by pumping out messages at a higher power because bigger is better and that helps MAGA for the true believers.

Meanwhile, the MeshPocket is borked, the MeshSolar never worked properly and HaLow seems to be random. Heltec have the potential to be adopted as a core to a best selling product worldwide if they let their tech fans help.

It’s not just that, the LNA (receive amplifier) also means it can hear stuff that most other devices can’t which makes the whole thing asymmetrical and out of sync with the rest of the network.

Technically yes & no. We can probably disable the PA & LNA but it will need modifications to the existing libraries to control these chips.

The v4 is also touted as having better solar facilities, which it doesn’t. :man_shrugging:

Simplest to just buy v3’s for the foreseeable which in no way has been slated for EoL. Even with library mods, there may be issues arising in v4 until it has been well exercised.

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It’s a bit like sex ed: sometimes it’s better to explain and support than not doing anything at all.

I’ll draft some basic support for RadioLib next week or so, so some of us can run it side by side with a v3 for a while. But as none of us in the LW world have seen a proper comparison yet, as Nick says, the known good route is to go v3 now.

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I managed to reach TTN! Once it was clear the issue was with the board, I emailed Heltec’s support, and all it took to make their library work was to set the correct flag:

If your board is V4.3, you need to select the KCT8103 option in the Tools menu. After that, the LoRaWAN examples included will work properly.

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Cool - that will allow us to trace the code to figure out the secret sauce.