ublox NEO-M8T Pi Hat

Paul Theodoropoulos paul at anastrophe.com
Sun Apr 21 01:42:07 UTC 2019

On 4/20/2019 18:33 PM, Gary E. Miller wrote:
> Put u-vcenter where the sun does not shine.  ubxtool should do everything
> that your need.
Ah, wasn't aware of ubxtool. Will check it out.

> Yes, the default is u-blox binary.
>> Now I have it putting out NMEA - but there's still one
>> string in the output in hex, and i'm not really sure what it is or
>> how to fix/hide it, or if i even need to bother? - example from
>> gpsmon:
> ubxtool will decode those u-blox binary bits.
>> b562021570015eba490c02009a400208120b0101fcc8397c24fc914e744191f281f0aaad9a4167f8b6c3000200000000120b0f0c01009
> b5, 62 is the header.
> 02 is Class RXM
> 15 is ID RAWX
> So you have UBX-RXM-RAWX messages.  Perfect if you want to get RINEX.
> Otherwise not very useful.
> You can use ubxtool to revert to defaults, turn off binary and enable
> 	# ubxtool -p RESET
>          (wait)
>          # ubxtool -d BINARY
>          # ubxtool -e NMEA
Sweet. Yeah, I found the strings to disable as mentioned in followup. This 
would have made it much less tedious than going through vcenter msg list 
one by one.

> One "neat" thing is that I'm getting three SHM outputs - SHM(0) GPS,
>> SHM(1) PPS, and SHM(2) PPS.
> Weird.  Sounds like you have PPS on the serial port, and you also put
> /dev/pps on the gpsd command line?

Ah, so maybe I'm folling myself? That would make sense, since there's only 
one PPS pin wired up, so how could it see two? Yes, I had pps0 on command 
line for gpsd startup.

> ebay listing: https://i.imgur.com/sdBlMFW.jpg
> I have seen similar, as a board, not a HAT, for under $80 at
> csgshop.

Yup, saw those. Since my primary (public) stratum one was dead, and my 
backup one is slightly less accurate, I wanted to get back up and running 
as quickly as possible, so for $20 more having an (almost) fully wired HAT 
was desireable.

Paul Theodoropoulos

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