Dreamcatcher Chat Application


#62

Oh and that’s simply an Unsigned Long constant.

–Konrad, WA4OSH


#63

BTW, I’m about 45 miles from Semtech in Camarillo, CA, if anyone needs a task done.


#64

Isn’t this forum for people who have or want Dreamcatchers? how does the direct 2.5 GHz antenna interface work? if it uses LoRa people could , with the right settings, safely use it in the ISM bands if they have a directional antenna they can extend the range and point their transceiver at their fellow Dreamcatcher users one at a time, or even have a multi antenna setup on a splitter.


#65

I think the answer is yes…

I have got it to generate a 400khz wide lora signal at the US 915 ISM and EU 866 MHz
And to communicate with a similiarlly configured second Dreamcatcher.
Probably could easily tune to the 433 MHz band
So for I haven’t figured out how to change the program and/or recompile it with different parameters.

I have not used the direct sma interface yet since I don’t know how to change antenna ports … yet

But I just started using it this week.

My goal is to eventually use external rf amplifier and a transmit/receive switch.


#66

I have an Amateur Radio Licence in Canada. Is it possible to use the direct antenna connector without LoRa as well? This isn’t a requirement for me because I do have other options for radio communications. A city to the south of me had some bad forest fires in 2003 and 300 homes were lost and in the past few years spring flooding has become quite a bit worse. They have started a HamWan There is a link to a tower here but so far no sector radios so we can connect to it… Still waiting. Their website has a map of their towers and possible coverage.

http://www.hamwan.ca/


#67

My real only reference is to the data sheet at the bottom of this link
https://www.semtech.com/products/wireless-rf/fsk-transceivers/SX1280


#68

Thanks for the link… FSK can be used by Amateur Radio…


#69

Gary,
You must be in Victoria or Vancouver then. I’m in the Seattle Metro area, home of the original HamWAN. Besides using modified 5.9 GHz gear to connect to HamWan, it should be possible to run LoRa gateways at HamWan locations to extend the network into areas where there’s no line of sight to a tower.

Perhaps someday we will be able to communicate over HamWAN across the border, without ever touching the Internet.

–Konrad, WA4OSH/7


#70

Not quite that far west, right province though. Victoria appears to have a usable signal according to the Puget Sound Data Ring website. The British Columbia Interior HamWan was started in Kelowna. It is actually listed on the Certification page of your HamWan’s website. Some of us from other cities in the valley were invited to their technical meeting last summer but only about six of us from Vernon showed up to hear what they were up to. I’m happy that Vernon BC, where I live, has a link to a tower. Unfortunately, as I said, no sector radios yet… I’ll have to save up for a client radio anyway. Kelowna already has four active towers and a dedicated link to the Internet at building that services IT companies.

Gary is what my Uncle Edgar was called, I’m named after my uncles… just in case you look up VA7GHA and find the names don’t appear to match.


#71

Yes. You can use the 2.5 GHz antenna interface by connecting to the Direct SMA connector and turning off the mixer and LO.

This is not your Mom’s $15 LoraWAN card. Why would you want to use the following ISM bands?
433 MHz: It’s shared with the ham band, but it’s full of remote controls
868 MHz: Not in the US
915 MHz: Shared with all sorts of stuff.
It’s all part 15. You can’t push any power behind the signal.

Why not use the mixer that you paid for to get you to a nearly completely empty ham band?
1288-1294 MHz

Directional antennas … Loop beams with lots of elements are really easy to make.
Amplifiers at 1.2 GHz for LoRa … wow LoRa has a PAPR of nearly 1. This means it’s envelope modulation. Your amplifier does not need to be ridiculously clean or have tons of headroom.

Yes, you can have sector antennas on 1.2 GHz. You don’t want a splitter, you want separate transceivers.

–Konrad, WA4OSH


#72

Konrad,
I have a TH-F6A. it receives up to 1300 MHz. Wonder what I would hear at 1290 MHz. Not exactly test equipment, but it works. Also I’ll try a regular RTL-SDR dongle and SDR# to see and hear. First got to load Chat into Armbian.


#73

Gary,
Are you all allowed to use spread spectrum in Canada? Here in the US, we were allowed only FH and DS, but that’s been expanded a while to include newer SS modes. The DreamCatcher makes that possible.

–Konrad, WA4OSH


#74

@donde
There’s an Icom D-Star repeater here in Bellevue, WA. 1247 MHz
There’s an Analog TV repeater at 1253.25 MHz
There’s four old-school FM repeaters with output near 1292 MHz

And a whole lot of nothing up there.

You probably can hear the audio from a TV repeater if there is one
You might hear the FM repeaters ID once every 10 mins.

You won’t hear LoRa with your handie. It’s too wide.
You can see it with you RTL-SDR dongle. I would suggest doing that first.

This is a screenshot of my HackRF One … my DreamCatcher transmitting LoRa.

–Konrad, WA4OSH


#75

I’m fairly new at this but here is something from the RAC website about it in the 70 cm band with the center frequency listed as 444 MHz. Radio Amateurs of Canada are like the ARRL.

… (9) Spread Spectrum centre frequency, secondary, operations per IC bandwidth limit of 12 MHz (max. spreading), may occur within these sub-bands, but must not cause interference to primary Amateur systems.


#76

OK … In Canada, I see you have spread spectrum frequencies…
Band plans

444 MHz
922-928 MHz
1288 - 1294 MHz and 1260 - 1270 MHz ???
2438-2450 MHz
I don’t see much SS on the Microwave Bands Page

Maybe LoRa qualifies for being wideband in the 13cm band?

–Konrad, WA4OSH


#77

I didn’t think you could use LoRa on amateur bands because it was proprietary, I guess if it isn’t encrypted… it might be ok.


#78

There are all sorts of protocols that are proprietary E.g. DMR (Motorola), D-Star (Japanese std, but the vocoder is proprietary), P25, etc.

LoRa’s PHY is pretty well understood and it’s all over the place due to unlicensed use in the 433, 868 and 915 bands world-wide. (868 falls in the cellphone bands here).

It’s not encrypted in the PHY layer.

You might want to run it by RAC asking about LoRa in your 1288-1294 sub-band … does it qualify as “broadband”? It can be 400 KHz, 800 KHz and 1.6 MHz wide.

–Konrad, WA4OSH


#79

Thanks Konrad for tips. Continuing … and the same for you. :grinning:


#80

Hey Konrad,
Heard LoRa signal just fine at 437 MHz. LSB, USB, AM, CW. S9 plus on the F6. Sounds like a carrier in background and a fast pulsing signal on top with a pattern. I think 6-7 times it pulses, then stops for maybe 1/4 second and continues pattern. Inserted a few inches of wire in SMA Direct connector. Guess I’m done till the next big challenge! Back to normal Outernet operations.


#81

Here is a table of why the Dreamcatcher has much potential

Typical Internet of Things LORA WAN (sx1276/7/8, sx1272, RN 2483,RN2903)

Bandwidth------- Spread Factor-----data bits/sec
125 kHz -------------- 6 ----------- 9380
125 kHz-------------- 12 ------------ 293

The Dreamcatcher (sx1280/1)

Bandwidth------- Spread Factor ------ data bits/sec
406 kHz ------------- 6 --------- 38600
406 kHz ------------ 12 ---------- 1190
812 kHz ------------- 6---------- 76130
812 kHz ------------ 12 ---------- 2380
1625 kHz ------------ 6 ------- 152340
1625 kHz ----------- 12 ---------- 4760