First experiment with a LoRa APRS tracker running on a 50 EUR board:
100 mW on 433.775 MHz from the car with a 2m/70 cm antenna on the roof: 231 km !
DB0SKY-11 1 2023-02-21 22:01:03 2023-02-21 22:01:03 JO20DP > JO31RH 231.0 km 71° 2023-02-21 22:01:03
This looks very promising for SOTA activators who want to show their progression ( ON6ZQ | SOTA2APRS )
Technical info: GitHub - lora-aprs/LoRa_APRS_Tracker: A LoRa based APRS tracker for ESP32 boards.
Tracking:
Very impressive!
I permanently installed my Lora tracker as DL1CR-4 in the car and my ODX is100km from the summit Auersberg to Leipzig.
Among other things, I use my tracker to find the car in the morning, hi. It’s hard to find a parking space here in the big city and there are so many options within a radius of up to 500m.
I get a bit confused the next day.
By the way. Tnx for my very first contact with the tube tx yesterday, Christophe.
73 Chris
I built myself a small LoRa tracker last year which I use when riding my moutainbike.
Here is the case for 3d printing:
It’s essential that lot’s of people build their own iGates, it’s even easier to setup than the tracker. Peter, OE5BPA also wrote a software for LoRa iGates:
For SOTA I still use a regular APRS tracker (144.800) in combination with a portable iGate built into my car:
Of course, the range of the LoRa tracker depends on the number and position of the iGates. In my hometown area there is enough of it, I run an iGate DL1CR-1 myself.
The effort for this is low and the installation is quite simple. With significantly less than 100 euros, a 70cm antenna and an old mobile phone power supply you can be there.
There are lots of hints on the internet.
73 Chris
It’s good to see someone else playing with LoRa, here’s my iGate (439.9125MHz - MB7UWS-2)
https://aprs.fi/#!mt=roadmap&z=11&call=a%2FMB7UWS-2&timerange=3600&tail=3600
Sadly, it’s only one of a small number here in the U.K at the moment.
Regards
Dave (M0JKS)
Isn’t the “recommended” frequency for APRS LoRa 433.775 MHz (like 144.800 in Europe for APRS AFSK) ?
Hi Christophe
Sadly not here in the U.K. The RSGB and Ofcom (the U.K Spectrum regulator) would only allow me to operate on 439.9125MHz for an unattended LoRa iGate. I argued for 433.775MHz (same argument as you - recommended frequency etc etc) but alas I lost.
Here’s a list of all the 70cm AX25 repeaters in the UK.
https://ukrepeater.net/packetlist.html?filter3=70CM
There are three on 439.912MHz. My APRS AFSK iGate (MB7UWS) is on 144.8MHz so who knows why they decided on a different frequency from the rest of Europe for LoRa.
Regards
Dave
Output power and the duty cycle may not have been wanted in the LPD433 ISM band.
Bang on Andy - here’s the RSGB’s explanation (thanks Steve):
It’s because the bandwidth of LORA in the LPD part of the band, plus the issues around the primary user in that part of the band. When someone proposes something new, it’s very difficult to assess the potential impact. Are we looking at only 20 of these stations or 200 or 2000 of them. So they have to do look at the worse case. We have also been told to now allow any amplifiers either because of the increased spectrum noise that potentially comes from these low power device ICs etc.
As it’s not a DX mode I don’t see an issue with having a different channel? 439.9125 MHz is well out of the way of low power devices so those issues shouldn’t occur.
I already have too many pies to stick my fingers in so I have avoided looking into LoRa and friends. My quick skim of the internets suggest lots of LoRa in the UK is on the 868MHz band (433-434 x2). A former work colleague (self-employed embedded consultant now) lives about 500m away and has a Things Network node running… I’ll wander down and have a chat with him about how much traffic he sees and what bands etc. he uses.
Happy to host a LoRa Digipeater at my woods. This is the 2m APRS coverage from the site. 12 Volts available. DM me if anyone wants to do this.
Hi Richard,
I did a test run from home (near Bakewell) up to the car park at the Cat and Fiddle just before Christmas with the LilyGo TTGO T-BEAM + 70cm mag mount (no parking fine this time), and it was tracked by my LoRa iGate (MB7UWS-2) for a lot of the journey. This was somewhat impressive considering the NoV stipulates a maximum EIRP of 13dBm.
http://www.lilygo.cn/claprod_view.aspx?TypeId=62&Id=1281&FId=t28:62:28
I even carried it up to G/SP-004 but sadly nothing else picked it up (there are only three on 439.9125MHz in the U.K, so no surprise there). Another in your location would be great for activating the Clwydian Range, Moel Y Gamlin and beyond; and for covering the Peak District from the west side.
Dave
Hi Dave (@M0JKS)
Just trying to piece together all these bits of hardware and terminology.
You’ve applied to OfCom and received an NoV to operate an iGate (which I think is an APRS device bridging RF (LoRA in your case) to the Internet) statically located in or near Bakewell UK.
Separately, you have a LilyGo gizmo (that looks quite cool) which you’ve wandered around with and it beacons out APRS formatted data with your callsign, location etc and that is picked up by your static iGate.
Assuming the above is correct, what s/w is running on the wandering LilyGo?
Like Andy (@MM0FMF ) I have too many fingers in too many pies but I did acquire a pair of LORA boards from Adafruit which have long collected dust. At some point, I’d love to try using them and maybe as M0SNA and back in the UK is a good time.
EDIT: After a little internet research I found this video which pretty much answers my questions. Fun looking project. Tech Mind LORA APRS
Paul
W6PNG/M0SNA
This is my LoRa tracker from a few years ago. Best range was 10km, it was originally made for the ebike and wakes up every 5 minutes to do a report. Battery endurance is 5-7 days.
Glenn, VK3YY.
Hi Paul.
It was the Tech Minds video on Youtube that got me interested in APRS over LoRA.
There are two LoRA modules made by LilyGo; one that’s used for the iGate/digirepeater:
https://hamparts.shop/lilygo-ttgo-lora32-gateway.html
and the other as the tracker:
https://hamparts.shop/lilygo-ttgo-t-beam-tracker.html
The latter has GPS and a 18650 battery - which lasts for several days. The iGate doesn’t need these so is a tad smaller.
The reason I chose these modules was that Peter Buchegger (OE5BPA) had done all the hard work in getting them up and running on APRS. The github repository is here: peterus (Peter Buchegger) · GitHub.
To get the software for the iGate module do the following:
git clone https://github.com/lora-aprs/LoRa_APRS_iGate.git
and for the tracker:
git clone https://github.com/lora-aprs/LoRa_APRS_Tracker.git
As the instructions in the git repos say, to compile the code for both the iGate and tracker you need to install Microsoft’s Visual Studio Code,and then the platformio IDE. Follow the instructions here :
A professional collaborative platform for embedded development · PlatformIO
I’m a Linux hacker, so having anything to do with anything that comes out of Redmond makes my uneasy, but actually it worked fine. I installed
https://code.visualstudio.com (for Linux) and then followed the instruction in the above post to install the PlatformIO IDE. I’m sure the Windows install would work just as well if you prefer using that.
You need to do this as the configuration needs to compiled into the final image. Attached is an example of the is-cfg.json json file that you need to edit to supply various bits of information like callsign, WiFi SSID, GPS co-oridinates and various other parameters. Here’s a screen shot of mine :
Instructions on how to compile (which buttons to press in the IDE) are in the above URLs. Once compilation is complete, plug the APRS node into a USB socket and follow the instructions on how to download the image to the node.
Dave
I forgot to add, the Ofcom/RSGB NoV is required as the LoRA APRS iGate is unattended - I’m allowed to leave it running as long as I can shut it down remotely. I think MB7UXX is assigned for i-Gates (which forwards APRS packets to and from the APRS-IS via the internet), and MB7VXX is assigned for digirepeaters.
You apply for the NoV this RSGB URL ;
ukrepeaters AMATEUR RADIO REPEATERS IN THE UK
and
RSGB ETCC FORMS CENTRAL
Dave
As I understand it this only applies if the iGate actually TX`s mine has all TX Disabled and is RX Only!
Although its currently off as the Micro USB socket has gone iffy
Matt 2E0MDJ
For information, Belgian regulations provide an exception for individual APRS amateur radio stations which can remain unattended without a dedicated licence.
Is this the case in other countries too?
Use of 70cms in the UK is sensitive due to use by the Ministry of Defence. One main concern is the AN/FPS-126 missile warning radar at Flyingdales which operates close to 430MHz. So it is more difficult to get unattended operation permission for 433MHZ compared with 439MHz.
