• The GNSS receiver on my Bangle.js 2 was able to get a fix fairly quickly. However it only finds 5-8 satellites at a time (I've occasionally had up to 10, briefly). Looking at the output NMEA sentences:
    $GNGSA,A,3,01,07,08,17,21,30,,,,,,,3.4,1­.7,2.9,1*33
    $GNGSA,A,3,,,,,,,,,,,,,3.4,1.7,2.9,4*3E
    $GPGSV,3,1,10,01,49,149,28,07,52,194,20,­08,39,058,14,10,05,035,,0*6A
    $GPGSV,3,2,10,13,17,304,,14,43,298,25,17­,26,242,36,21,57,097,29,0*67
    $GPGSV,3,3,10,27,08,060,,30,61,255,27,0*­6C
    $BDGSV,1,1,00,0*74
    $GPTXT,01,01,01,ANTENNA OPEN*25

    It's found 10 GPS satellites ($GPGSV) but only 6 are used for the fix ($GNGSA; sats 01,07,08,17,21,30). It doesn't look like it's even trying to find GLONASS satellites; there's a line for Beidou ($BDGSV) but no satellites are listed. Galileo satellites are also missing. uBlox receivers allow the choice of frequencies; the inexpensive ones allow the choice of two (e.g. GPS and GLONASS or GPS and Beidou). There must be a way to turn on at least the GLONASS frequency.

    The last line worries me a bit:
    $GPTXT,01,01,01,ANTENNA OPEN*25

    From the datasheet Gordon linked in, the choices are:
    示例 $GPTXT,01,01,01,ANTENNA OPEN*25
    表示天线状态(开路)
    $GPTXT,01,01,01,ANTENNA OK*35
    表示天线状态(良好)
    $GPTXT,01,01,01,ANTENNA SHORT*63
    表示天线状态(短路)

    This implies that part of our problem is that the antenna is not connected, or that there is no antenna (open circuit). If anyone has done a teardown of the production units, this could be verified.

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