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  • Thanks for the response. I think I had seen the AppNote before, but was not able to make the
    connection with the code in GPS-comms.js. Its a great bit of code, just needs a few more comments
    to explain what it is doing.

    What I would like to acheive is to have a OS GRID ref showing as a widget or a line of TEXT in the front screen of the watch. Normally GPS will be switched off so the grid ref line will be skipped
    and not displayed. When I do a new fell walk it is useful to have a grid ref every now and then.
    Using a 1:25000 OS map you can only really only see a 6 digit OS grid ref and that puts you in a 100m square which is good enough for general map reading. Say I walk at a speed of 4km/hr; thats 67m per minute. So I'd be happy to take a GPS update between 1-2 minutes apart. When I stop and look at the watch I would only have to wait a max of 2 mins before the GRID REF was refreshed. I could have a little coundown value that would show me how many seconds ago the GRID REF was updated.

    What I read in the AppNote:
    Power Management Considerations for u-blox 7 and M8 GNSS receivers (UBX-13005162 - R01) Page 6:

    Smallest average current consumption is obviously achieved when the update period is long

    Section 2.3.1 shows a chart, with PSMOD set to 30seconds the average power consumption is 2mA.

    The question is how to set this value using the Bangle JS framework.

    Once I understand how to use the code in GPS-comms.js I can try a few experiments, to see what is practical.

    I see Gordon has requested votes on the next in depth tutorial, so I have upvoted for a GPS tutorial.

    Back to more studying of GPS-comms.js against the datasheet, I guess I am going to
    end up knowing more about GPS than expected.


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