I’m unable to join TTN.
I’ve recently purchased the PicoW and E5 module and following the video and guide to set it up. I get as far as having created my TTN a/c, obtained the AppID and inserted into code of Lora_Transmit_data.py. What I get is…(ID’s masked)
MPY: soft reboot
LoRa radio is ready
JoinEUI: XX:00:00:00:00:00:00:XX
DevEUI: XX:XX:XX:XX:XX:XX:XX:XX
AppKey: XXXXXXXXXXXXXXXXXXXXXXXXXXX
+DR: DR0
+DR: AU915 DR0 SF12 BW125K
+JOIN: Start
+JOIN: NORMAL
+JOIN: Join failed
+JOIN: Done
Join Failed
It seems I’m unable to join TTN. Per image I’m in High St, Mt Kuring-gai, Sydney 2080 and there is a Lora gateway nearby.
What am I doing wrong? I guess I could drive over there to get closer…?
1 Like
I drove closer to the gateway and picked it up ok. Where you see “Church Street” at bottom of the image is the location where the signal drops out. About 500m but near the top of a ridge.
SNR 1.8, RSSI -112
Granted I am useing the smallest antenna: * CE09458 - 915MHz uFL antenna
Can someone confirm if I buy the following antenna and cables plus raise it high enough I should be able to get a reasonable signal?
LoRa Fiberglass Antenna Kit; 902-928MHz-3dBi with Antenna Base SKU: SS318020652
RP-SMA to uFL/u.FL/IPX/IPEX RF Adapter Cable SKU: ADA852
Interface Cable - SMA Female to SMA Male (10m, RG58) SKU: CAB-21281
2 Likes
Hi Mark,
You should just need closer to LoS to the gateway to get service.
Were you testing the module in your house?
I wasnt able to find any nice tall antenna masts for a gateway like the ones mounted in Lake Mac
(Might be inside the house or mounted directly to the top of a roof)
What kind of project were you looking to use this for?
WiFi around you house might be a better alternative for connecting your device to some kind of dashboard.
EDIT: Just loaded up Google Earth to check the elevation
2 Likes
Hi Liam,
I was testing inside my house, so granted the potential for lots of interference. Same result when testing outside at my location.
Going closure is not really an option. Hence thinking to go “up” via an antenna. My application is sensing soil moisture content with a * CE09640 (x1) - Capacitive Soil Moisture Sensor (v2.0) and reporting this over time, i.e. weeks/months back to MQTT/InfluxDB/Grafana.
I can try wifi to start but the eventual field application in another part of Australia means there won’t be wifi…however potentially better LOS. I’ll start with wifi. Thanks for your advice!
2 Likes
Hi Mark
That antenna has a quoted gain of 3dbi which will be cancelled if you need to use that 10M of extension cable. This will have an attenuation of between 3.5db and about 6db depending on the quality of cable used. The actual figure differs a bit between manufacturers
But having said all his your signal could be very much improved by antenna position which this cable might provide.
This sort of thing is a very much suck it and see situation without some specialised equipment like a decent spectrum analyser or some other tuneable signal strength meter. In fact a means of isolating and measuring (at least a comparison measurement if actual signal level not practical) your wanted signal. Actually some tuneable TV signal strength meters might sneak up into the low 900MHz region.
Cheers Bob
3 Likes
Hi Liam
Those path profiles are assuming a “flat earth”. and have to be corrected for earth bulge which is usually considered at 4/3 actual radius for RF although this can change. Although this would not be significant over this distance it should be kept in mind along with Freznel clearances.
If the ends of those profiles represent Mark’s actual position and the Node’s position he has not got a lot going for him as far as “line of Sight” signals go. BUT 900MHz to 1000MHz or so is the frequency area where Tropposcatter systems operate for a reason. In Mark’s situation this could work to advantage. Moving around even a few metres might be the difference between no signal and a useable one. I don’t think he is going to get much of a result with any sort of built in antenna so should look at the external one
To illustrate some perspective I once (many years ago) installed a Troppo system from Groote Eylandt to Gove which was basically over water but 193kM. TX power 10W. Got a good reliable result BUT to get this a quad diversity system was used comprising 2 transmitters on different frequencies feeding 2 dishes several wavelengths apart regarding distance. At the receiver end was 4 receivers fed by another 2 dishes 2 receivers on different frequencies on each dish. The idea here being that the signal used at any one instant in time was the receiver with the strongest or quietest signal. This situation changed rapidly and the receiver in use was never apparent. And the dish antennas. Andrews Grid Packs, 7M wide and 6M high with a design gain of 30db and a measured gain of 32db. Not your typical back yard installation.
Getting back to Mark’s problem I think that “bulge” on the right hand side of the profiles might beat him.
The antenna he is using is supposed to be 6dbi whereas the one proposed is 3dbi so on paper should be worse. BUT if the 3dbi antenna was to be mounted on a proper ground plane it could perform better than the one in use. Or maybe a directional device.
Cheers Bob
3 Likes
