Spreading factor with WifiLora(V3)

[NewGuard]

Hi Barbara and Peter. Thanks for the inspiration, posting your code, and being very informative with the issues you’ve had to work through with various hardware and software configurations. I’ve soldered a few hoperf modules and hooked them to esp32s (I use the sandeepmisty LoRa.h library with these). And I have one heltec lora wifi (v3) board with the oled which I want to use as a roaming range test device (I use the LoRaWan_APP.h libarary for this one). I can get all the modules to communicate with each other as long as the spreading factor is left at 7. If I change the spreading factor, the hoperf modules still communicate fine, but on the heltec device setting any spreading factor other than 7 (6 or 8-12) any tx or rx activity at any power level just doesn’t work at all. Would you have any insights or suggestions for me? I’m stumped. I’m happy to use all hoperf modules, but I was really wanting to have the heltec with the oled to test range and line of sight issues for certain placements. Cheers mate. And well done on what you’ve achieved so far! I’m going to have to go over your pages several times and dig a bit deeper.

[UniquePete]

I’ve not actually tried to vary the spreading factor. In the early days, there was a problem with the sync word, but that was all that had to be changed so that’s where I left things.

I’ll have a little play around this evening any let you know if I come up with anything.

[UniquePete]

I’ve just run several tests using a Heltec WiFi LoRa 32 V3 receiver, which uses the Heltec Radio library (LoRaWan_APP.h) with both a Heltec WiFi LoRa 32 V2 and ESP32 + HopeRF RFM95W (my A4a LoRa ESP32-WROOM-32 board) senders, which each use the Sandeep Mistry (LoRa.h) library, and they seem fine with Spreading Factors of 7, 8 & 10 (just a sample of the available Spreading Factors).

If you haven’t already, maybe check my page on LoRa configuration for compatibility between the two libraries.

[NewGuard]

Thanks Peter. I’m currently experimenting with RadioLib.h by jgromes to see if that works. I might also try the lora.h on the V3 at some point too. I’m looking to use these Lora modules as security/ notification devices in rural Australia, so I know that tens of kilometers of range will be needed at some point. If I have successes with these other libraries I’ll let you know. Cheers, Bryan

[UniquePete]

Note that the HopeRF RFM95W and pre-V3 Heltec modules use the Semtech SX1276 LoRa Node chip while the Heltec V3 modules use the newer Semtech SX1262 LoRa Node chip. Most libraries seem to support the older SX1276, but only a few support the newer SX1262. The Sandeep Mistry (LoRa.h) library, for example, does not include SX1262 support. So check that any library you do use with Heltec V3 modules explicitly notes that it supports the Semtech SX1262 LoRa Node chip.

[NewGuard]

Hi Peter,

Mate, you’re a champion. I had looked at the code snippets you had provided before and checked and rechecked my own settings, and couldn’t find a difference. But I figured I’ve had nothing to lose and a working setup to gain, so I grabbed the header file with your variable settings and used that in place of the lorawan_app and lora.h #defines/variables and it instantly started working (heltecv3 tx –> hoperf rx). I’ve gone back and tried to find settings that were different and the only thing I can see is that my lora.h settings didn’t include the enableCrc() function. So far so good. I’ve tried both enableCrc() and disableCrc() using the lora.h on the esp32 with the hoperf board being the receiver and it works with either setting so that doesn’t really make sense to me –so there must be something I’m missing (I’m leaving crc on as the heltecv3 has crc true as per your txconfig settings). The hoperf boards talk to each other with no worries, so I think the wayward settings must have been in the heltec factory test sketch. Disappointingly, the heltec documentation is pretty minimal and not very helpful. Anyhow, with a spreading factor of 12 I’m getting an rssi of -30dbm and a snr of 10.5db with the antennas about a meter apart. I’m so chuffed. I’ll make sure the radio traffic can go the other way this morning and then head out to the bush and see what my line of sight range might be in real world conditions. Thanks again for the help and advice, it did the trick. Cheers

[Author]

Posts