Adventures in LoRaWan & TTN Part 6 - Re-mapping & Improvements

Adventures in LoRaWan & TTN Part 6 - Re-mapping & Improvements

One thing I didn't realise is that Part 5 posted before Part 4. Seeing as I missed Part 4 I thought I'd merge it into a Part 6.

Since I got my gateway I've done a lot of mapping and experiment mapping at different SF factors. However a lot of this data has had changes inbetween with improvements made to the gateway by shortning the cable to the antenna, a better U.FL to SMA Connector and more.

However as shown below quite a lot of the data is outdated with the range with some measurements being over a month old.
Screenshot-from-2018-02-07-12-12-18

So I decided to reset my coverage for Great Yarmouth, to do this you move your gateway 100M from where it was, wait for TTN Mapper to reset and then move it back.

Next I wanted to improve the reliability of mapping. Currently using TTN Mapper phone application if you loose phone signal the system can't log the packet. However even with signal I've noticed that it doesn't always seem to pickup packets. I then powered up my transmitter and setup the app on my phone. After a couple of minutes I checked and indeed 57 packets were transmitted by my node and picked up by TTN while only 44 were logged in the app. GPS Accuracy can also be an issue as the mapping app requires it to be within 20 meters however even with my phone sitting in the same place on my desk the position did vary quite a lot.

Even with the screen on I noticed packets were getting lost. With in one test 26 out of 36 arriving, a second further test had all 16 packets come through however I did loose some while simulating a mobile network change.

After some more investigation I found the main improvement was made when changing the battery settings. This can be done by going into the settings of android and allowing it to take up full battery usage.

I then done some more tweaks and brought yet another SMA connector. This was from where the one I was using was from amazon had no specified impedence and cost £1.50, where as the one I ordered cost £6 from a reputible component supplier and was specced. However when it arrived it actually worked worse.

I then sent that one back for being faulty and brought this Adafruit branded one from The Pi Hut, I then tested all 3 SMA Connectors and the one from Amazon & The UK supplier both got around -73 RSSI from a node placed in my kitchen. When changing to the adafruit connector I got an improvement up to -70 RSSI!

At the same time I had also changed the software to use the Resin.IO Image as this uses a slightly newer packet forwarder which is more reliable.

Finally I changed the node I was using in my Car. I was using a PyCom LoPy board however because the board itself has no USB port on and I didn't have one of the breakout boards I changed to my LoRa32u4 II, the ideal thing with this is I was able to connect it to the USB port in my Car so that instead of charging up some batteries and manually turning it on and off It starts with my car's ignition. Excellent.

And here's the results so far. I have a few more roads I plan to drive down over the next few weeks however at the moment there's a lot of roadworks happening preventing me going down some.

Screenshot-from-2018-02-24-11-52-33
TTN Mapper Colour Radar View

Screenshot-from-2018-02-24-11-52-07
TTN Mapper Area View

rssi_vs_distance--1-
TTN Mapper RSSI Vs Distance

And that's it for this post! I'm going to try and target to do a new post every Wednesday!


Enjoy this blogpost? - I'm currently funding for a RAK831 LoRa Concentrator. This will lead to another series of blogposts on setting up a different LoRa Board and possibly include a development series of a Backpane I'm developing. You can donate via Ko-Fi by using the button below

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