Hi Nick,
There is no feedback on the BBC Micro:bit with the Pi Supply LoRa Node - it either works or doesn’t. I was able to see a pulse of RF around 868MHz with an SDR receiver, but was not able to see what data it was transmitting. I can see from the TTN maps that some places are well served by gateways, but not here in Leicester. I was using a ground plane antenna on the top of a pole outside, and am fairly high. I guess the way ahead is to set up another LoRa Node with a cheap LoRa module, and look at data from it, rather than relying on the TTN network.
Hi Tony, if you fancy a short (?) drive I know the gateway in Lenton (NG7 Post Code area), Nottinghm, about 100m from the QMC is online and picking up ok inside the ring road - it will be online until next Thursday then will have to shut down for a future relocation… (Called out here: TTN Nottingham, UK, needs new host site(s) to relocate gateway(s) ) Approaching from the M1/Services you will likley also get a couple of ‘pings’ from the Rememberance Way roundabout near the park ‘n’ ride as you head down into the town…~4km LOS.
If you peel of the Clifton Blvd onto the A6005 you should get easy connection to the GW Good luck if you want to make the effort… Let me know if you try and I will look for live data/RX Count updates on GW.
Hi Jeff
I have got my device going sending GPS data (hopefully), so I will take you up on your suggestion - probably come up to Nottingham tomorrow (19 June), mid morning.
Tony
You’ll have to code it for Point to Point (P2P) as whilst your other node may hear the transmission (if it’s lucky, there are 8 frequencies it may use), the encryption will leave it unreadable. In theory, any one of the other Pi-Supply modules, all based on the RAK811, will talk to each other P2P - so you could use an Arduino or Pi as the other node.
I have written packet loggers that will take a ‘cheap LoRa module’ and record the packets it receives as HEX to serial terminal or connected SD card. Or just simple RSSI meters that display signal strength and packet details on a cheap OLED.
Problem here, is that with only one such node and it being single channel, you may not see a nodes intial packets.
Beware that TTN Mapper only shows gateways that appeared when explicitly doing mapping. (Right, @jpmeijers?) Also, the coverage that is shown is only that of explicit mapping. So, if there’s no regular mapping in some area, then TTN Mapper may not know about all gateways. (So: go mapping! )
The global map or community maps may show other gateways. But even those maps may be incomplete if gateway owners does not allow the location to be publicly visible.
I will dip into the console traffic page a few times through the morning and look for anything coming through…its a v.low traffic GW so anything you send will be obvious and I will see count increasing but only see traffic ‘live’ so may miss other than the count increase.
if you look here: http://noc.thethingsnetwork.org:8085/api/v2/gateways
whilst you are testing and look for the GW EUID (eui-c0ee40ffff293c43) in the list you should see the uplink count incrementing yourself as and when you Tx - then at least you will know your node if functional wrt Tx and sending valid MIC checked uncorrupted packets If you have set up an application and registered the device you should also see data arriving in your console.
ttnctl gateways status eui-c0ee40ffff293c43
INFO Discovering Router...
INFO Connecting with Router...
INFO Connected to Router
INFO Received status GatewayID=eui-c0ee40ffff293c43
Last seen: 2020-06-18 21:55:31.219382555 +0200 CEST
Timestamp: 0
Reported time: 2020-06-18 21:55:31 +0200 CEST
Frequency Plan: EU_863_870
Bridge: gs.v3.
IP Address: 127.0.0.1
Location: not available
Rtt: not available
Rx: (in: 0; ok: 0)
Tx: (in: 0; ok: 0)
I don’t know what timeframe is used for the statistics in the last two lines.
Thanks Arjan, I considered that also but figured easiest for Tony to just dip into a web page (can try and load from home/office before hitting the road) and load/refresh in the field vs battling with ttnctl…also whilst I thought of sending direct to the eui link I just thought showing the generic route in would be a good learning exercise for him
Uplink count timeframe in ttnctl I dont know but would be good to find out if anyone can shed light.
Also count (uplink) is currently 6992… very low traffic site per earlier where traffic tends to come in bursts every few weeks depending on certain vehicles and (pretty well known) sensors coming into the immediate area on a seasonal basis (close to a local canal with boat traffic and some vehicle traffic on the ring road embankment, or delivering to local pubs/shps/Queens Medical Centre, can generate local gateway traffic, hence my expectation of being able to identify if/when Tony is close by (assuming working node )
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…
- it will be online until next Thursday then will have to shut down for a future relocation… (Called out here: 
Good luck if you want to make the effort… Let me know if you try and I will look for live data/RX Count updates on GW.
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Hi Jeff