Re: [gpsd-dev] Field reports from Raspberry Pi GPS HAT users?

[Eric S. Raymond]

Frank Nicholas <address@hidden>:
> The issue is that they made a design decision on the Raspberry Pi 3 that ties 
> the serial baud rate to the CPU clock rate (by default).
> 
> This was done because the normal lines that fed the serial port were used for 
> the built-in Bluetooth.

Well, that would explain a lot.  Thanks.

> You have 2 x options - fix the CPU speed at a known, safe speed for serial IO 
> to be consistent, or disable BT.

I'll take "Disable the *fuck* out of Bluetooth" for $1200, Alex.

> Most people opt to disable BT.  See these posts to disable BT & re-map the 
> lines properly to the serial port:
> http://www.briandorey.com/post/Raspberry-Pi-3-UART-Overlay-Workaround 
> <http://www.briandorey.com/post/Raspberry-Pi-3-UART-Overlay-Workaround>
> https://openenergymonitor.org/emon/node/12311 
> <https://openenergymonitor.org/emon/node/12311>
> 
> There is an official Raspberry Pi post, but I couldn’t find it very quickly…
> 
> If you look around, you can probably find the post about fixing the CPU clock 
> speed also.
> 
> Note that this does not affect ANY other Raspberry Pi (A, B, B+, Zero or 2), 
> as they do not have built-in BT or WiFi.

Thanks, that was really useful and I think gives us a path forward.  I plan
to throw out systemd first.
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>