The real problem is the variety of frequencies and spreading factors only one of which can be monitored at a time with a node-class radio.
The encryption isn’t much of an issue for “does it work” testing of one’s own node because the device address is cleartext not encrypted, so unless there’s someone hiding in the bushes trying to be excessively funny by also sending packets from that address, you can tell when you have a transmission from your node. Also you can generally extract your own keys from the node or server.
Of course having mis-entered ABP keys could be a reason why the node isn’t manage to get through to the TTN servers…
An RTL-SDR also works at the level of noticing that a nearby transmission happened (likely across most if not all uplink frequencies, and all spreading factors) though most don’t attempt to use that to actually demodulate LoRa, but just see something with the characteristic chirp appearance.
This (with the result of getting the raw packet and status logs) is indeed the best solution, really the only cost effective one when considering the economics of time spent frustrated wondering what is going on
I’m going on a drive today to try to connect with the TTN gateway in Nottingham, but would definitely like code to use a bare RFM95 Chinese module for testing.
You will find an example of using an SX1276\8 (RFM95) as a packet checker in the SX127X examples folder here, it needs the included library;
Program “33_LoRa_RSSI_Checker_With_Display” is probabbly your best bet, you need to set the LoRa frequency and parameters your listening on in the programs ‘Settings.h’ file.
I guess it would not be difficult to make it swap spreading factors on a regular basis.
Hi Tony have checked a few time through the morning/just now with no incremental traffic - guess your not there yet or are getting success with some of the other GW’s in the area
Out for a short time (eWaste recycling trip!) and will check again later.
Personally I wouldnt go the RFM-9x route but YMMV (search forums for comments/experiences) e.g.
That said whilst I and many others avoid it professionally I know of many others who have had good success with the module so it’s your call, I will be retesting/trying for a personal project later in the summer (adapting someone else’s already complete system design/project and dont want to re-engineer RF/S/w) so am open to have my opinion/bias adjusted
I have been driving around nearby - currently in the entrance of Nottingham Trent Uni. No hits on my console. Heres a photo of the antenna on my dashboard.
The Lenton GW isnt high enough to catch once you come down from the rememberance way hill (around NTU) and down towards the ring road…as you come round the ring road and past the car show rooms and the bowling alley you get good coverage esp as you come off clifton blvd onto the A6005 in towards the town center past the QMC (on your left)
Thanks for your advice. I’m back home now, and with so many possible unknowns, I think it is best if I try and make a receiver using a Hope RFM95.
If I can show it is working before you shut down the gateway, I’ll take another trip your way. I’m in an Ioniq electric car, so miles cost virtually nothing.
Ok, as no traffic I assumed it was a fail. In your shoes I would rather start with a known quantity like the microbit + rak811 module ( I have used many of these) with proven ref design than start a roll your own and potentially having to debug both rf & library issues (lmic based & on which controller? ) … as well as a diy antenna! Have you tested/tuned & optimised the vswr for that unit?
Rather than clog the forum thread PM me to continue as and when you go back again. Let me know by PM your post code and I will look at if a potential site to loan you one of my community GW’s…
Ah, missed that bit of thread. When parked up you would seen it is carved out of the south side of hill top… wrong side of the hill and screened from gw’s in town! If you look at approx location on map above that was a small lane along side other side of remembrance way… am looking at how I can get a GW around area of that hill…
While the application’s and device’s Data pages in TTN Console are nice, they often just do not work for me when I have one open. So, just to be sure you’re not running into problems with TTN Console not updating the Data page (even though you have it open):
Keep an eye on the device’s Status (click its value, if any, to see an exact date; for OTAA devices this will also be changed if an OTAA Join Request was received and accepted, even if the device did not receive the Join Accept), and Frames up counter.
And Jeff - I’ve just realised I was reading your map wrong - it’s the distance measurement line - I thought your gateway was at ‘0 km’, so I initially parked in the small lane opposite Green Lane. But your gateway is at 4.25 km - not being familiar with the area I didn’t pick up ‘100m from QMC’. So I turned round the roundabout after Clifton Campus and headed back south - west, stopping at the Park and Ride for a few minutes. Now I understand, I will probably try again next week.
I doubt it as 90% of Remembrance Way, along with the Park n Ride are masked by the local topology and specifically Gotham Hill. And that assumes map placement is accurate as users often dither exact GPS location on Map for security reasons (I do for most by anything from 20-200m)
I haven’t had time yet to build my own receiver, so I am going to take a trip now to your gateway so I can catch it before you shut it down. Should be there a bit before midday. I have also added a button that gives larger spreading factor, so I will try that as well, so it would be interesting to see if the signal strength changes. I’ll approach Nottingham along the A453 with SF12, and change when I have got near your gateway.
Tony
YMMV!
Hi Jeff