PyBytes Location Source



  • Hi,

    I'm running a FiPy, with a PyTrack board, using LTE Cat-M1 with Hologram in the United States (Denver, CO to be specific). It's using a Verizon tower according to Hologram's dashboard.

    I'm able to pull a location via PyBytes "update location" button on the device dashboard. It's showing the location as being just down the street from where I really am (maybe 30 meters away, really close).

    My question is, where does that location data come from? I have PyBytes disabled now, and am trying to get a location fix locally, to no avail.

    I am unable to get a GPS fix, apparently, so I'm just wondering how PyBytes derives that location?

    Thanks!



  • @protean Hi, when you click on "get location button", Device scans the wifi networks around and sends the result to Pybytes. Pybytes is using Google location API to figure out and the location.



  • You can find a PDF from Quectel called Quectel_L76_Hardware_Design_V1.1.pdf. It describes pinout and circuit for external antenna. I have no idea how easy it is too modify the pytrack board.

    My device sends a lot of \n, if I read the data too fast. I filtered the \n out before parsing the the sentences, because they pop up in the middle of a sentence as well.

    There are a lot of MTK sentences according sleep and wakeup. Some seems to store the almanac inside the L76, so that it can get a fix faster. But I never managed to wakeup the L76 after sending it to sleep via MTK messages. You can find them in a file called QuectelL76-LGNSS.pdf

    I don't know how legal these two files are. The watermarks say it is confidential. If you can use only legal documents, you have to ask Quectel and not Google for the documents.



  • Just updating, I found the following:

    https://forum.pycom.io/topic/1269/pybytes-middleware-platform-update

    Geolocation: Pybytes can locate your devices doing a simple wifi scan to your device. The system uses Google Geolocation Services and provides an accuracy of approx 20 meters.

    Is there any documentation about the antenna? Does it need a certain orientation? Is it possible to solder on an active antenna via SMA connector? I guess I could just use some GPIO pins with an external active antenna, but seems like an antenna would be useful. As-is, the enclosure that is sold alongside the PyTrack is not very usable, as the battery blocks the GPS antenna. I'm running it off a USB power bank for now, to ensure the antenna is not covered.

    Anyway, after about 30 minutes, I was finally able to get a GPS fix with the device placed close to a window.


 

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