Normally you would print the co-ordinates to the serial monitor before the packet is sent.
Do Dragino provide a test program for their tracker that does this ?
the lgt-92 sends the position data over the usb/serial prot but I dont want to copy paste edit this - I thought there might be a smarter approach availabble.
I used two methods one using serial port and other through TTN cloud, I was receiving the data on the local server from there i am plotting it google maps.
I have one more question, did you guys try to open LGT-92 ? is it has a passive antenna or active ? the one i got has a passive antenna and i am thinking that might be the reason.
It uses a L70 GPS.
The L70 GPS works just fine on a small passive antenna.
What accuracy are you seeing ? Could you please perform an experiment. Take 30 mins reading and plot on maps ?
BTW i also have L70 chip with passive antenna.
Once I dropped the lgt-92 on the street the case was open and the film-antenna was ripped because it is glued at the inner side of the case. But I soldered a piece of wire on the platine and the tx-signal is now stronger as with the original antenna. Looks not that nice but works.
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Typically within 10m, normal for a GPS really.
I own the LGT-92 since a few days. Yesterday and last night I made some experiments concerning reproducibility and accuracy of position. 95% of the reported positions were in a circle with a radius of 12m around the real position. The device had no totally free view to sky.
I did some logging.
One lgt-92 with 30sec intervall and the other with 6min.
The data where recorded by data storage integration.
In my european region the variance of the coords from lets say N48.1223 to N48.1225 causes 20m and E7.5515 to E7.5517 is 15m. And the values do have only 4 decimal.
Within 100 measurements of the 30sec-tracker the position didnt change, there were less then 5 points that had another value.
The other tracker works with 6min intervall (and maybe deepsleep and cold fix) and gives 9 measurements that vary in lat xx.xx86 to xx.xx89 and in long x.xx69 to x.xx77.
This is much more as the 30sec-tracker and maybe due to the cold fix and that the device sends the first fix instead wait for 2-3 positions to get a better result.
So the worse the reception is, the more differs the position when the tracker does a cold fix. Dragino should improve the firmware (or someone else) to keep the gnss-chip in hot fix mode between the intervalls or send the gnss-fix after a few seconds to generate a better position. Maybe its better to keep the chip in hot-mode instead looking in cold fix mode 2min for a position were the chip has 20dB less sensitivity.
For a GPS fix from cold, the first fix does often have a much larger position error, this is normal GPS behaviour.
Now my LGT-92 is indoor since 3 hours and still delivering 11 position values per hour which are more or less ok. I dont think it makes a cold start every time. Imho it is very hard to find a first fix inside a building.
I was in the pub on Monday evening after the Reading TTN conference.
My L70 GPS equipped TTN tracker got a fix indoors after 2-3 minutes. Only using a small 13mm ceramic patch antenna on the GPSs too.
Maybe the L70 is in backup-mode during the sleep-phase of the LGT-92. The current consumption is abt 7uA then.
As the lgt92 based on open source, maybe someone is able to mod the firmware to keep the L70RL chip in hotfix mode to shorten the time to fix due to higher sensitivity what would save energy as well.
https://www.quectel.com/product/l70rl.htm
Hello everyone!
I wanted to inform you that I received a preview of this information: the new firmware for Dragino LGT-92 has been released: v1.5
you can download here: Dragino Download Server ./downloads/LGT_92/firmware/
here is the changelog:
Note: Explain for feature detail can be found in manual.
v1.5:
The v1.5 has a lot of change compare with the previous version. After upload to v1.5, user need to run AT+FDR to reset it to factory default for proper use.
*Add AT+FTIME to set GPS fix timeout
*Set location info to 6 decimal for higher accurancry, Payload structure change.
*Improve positioning accurancry by change the GPS fix logic.
*Support downlink command for change of : AT+CHE, AT+CONFIRM, AT+MD
*Add AT+LON to enable/disable LED flash.
*Add feature, so the tracker will send a uplink packet immedietely when Alarm is active.
*Add movement detect feature.
thanks, I will test tomorow !
I have a few problems, look at this: https://www.thethingsnetwork.org/forum/t/dragino-lgt-92-lorawan-gps-tracker/21817/52?u=giobert
Test done today. I have two LGT92. One as ever work well and work well with the new firmware. The second LGT92, never find GPS data. And V1.5 don’t fix it. I know my second LGT92 is break about GPS.
I also own a LGT92 and it even finds GPS-signals indoor. Maybe there is something wrong with the GPS-antenna. If you know how to do just open the case and have a look at the antenna and its connection to the board.
Hello. I do what you explain. I know my LGT92 is in default. Edwin have send to me a new lgt92 in remplacement. The new one works very well!