I just learned about OtherNet and am really interested in building out a TU for use on my boat while we are off-grid. It looks like the store is our of Dreamcatchers right now, so I was wondering if there was a how-to on using an RTL-SDR with the Bullseye LNB I just ordered. Also, would it be much work to port the code over to the LoRa32/oled/SX1276 modules that can be had for twentysomething USD on AZN? I’ll admit I havent looked closely at the code yet as I’m not a strong developer (but have done some arduino stuff in the past). Yes, I understand it would need at least a SD card slot added, as well as a bias tee.
-Craig
RE: sdr decoding, I see a bit in the forums on how to set it up, it looks like there have been two or three iterations and I’m not sure which one I should be looking at.
In theory, you can download with an RTL-SDR and external bias tee. In practice, I’m not so sure. The biggest obstacle is in demodulating the LoRa carrier at very low SNR. All of currently available software demodulators are not effective at the low SNR that Othernet operates at. The next hurdles is related to frequency offset, which the existing gr-lora does not accommodate.
There is one demodulator that recognized these issues and had plans for solving them, but I’m not sure how far the solution went:
If you just want to receive packets now, then it will be far easier to just buy a used Dreamcatcher. But if you are up for the challenge of LoRa software demodulation, then go nuts!
Where would I find a functional used dreamcatcher?
Ordered, Thanks!
Do you already have an LNB?
I ordered the LNB last week thinking I could easily decode it by adding an a bias tee to a SDR or with one of the LoRa32 boards I’ve already got. Turns out you use a narrower bandwidth than my units support. I may try swapping the LoRa module to the sx2781.
tbh, I was hoping to use one of these, add a 9-dof or a compass if they are cheaper, and a PCA9685 to drive a few beefy hobby servos for az/el/skew, then do some great circle math to aim the lnb, all in one little radome.
It looks like someone on youtube had the same idea and already did the work for the az/el/skew tracker… I havent been able to find their github repo yet though.
I’m not sure where you are sourcing your boards from from, but if you buy in volume you can get variants of boards made from many alibaba/aliexpress companies/distributors for not much $.
Are there anymore Dreamcatcher units available? Used is fine. I cuirrently only have the previous iterations prior to LoRa. Thanks!
Not yet, but additional pre-production boards will be built in August. I should have at least 50 then.
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Do you have any
Sorry, not yet. Hopefully in a month or so.