Re: [gpsd-users] NTP1 keeps going away.

[stinga]

On 09/11/17 20:20, Alexander Carver wrote:
> On 2017-11-09 11:34, Gary E. Miller wrote:
> > Yo Alexander!
> >
> > On Thu, 9 Nov 2017 10:58:38 -0800
> > Alexander Carver <address@hidden> wrote:
> >
> > > > One other thing that is a common problem.  Do you know the voltage
> > > > on your PPS pin is compatible with your pps input?  I'd like to see
> > > > your PPS output at almost swing zero to five volts.
> > > So you'd like to see his Raspberry Pi burned out, then.  The Pi has a
> > > 3.3 VDC input limit on GPIO pins.
> >
> > Ah, thanks, I forgot he was on a RasPi.  So it should be 3.3V logic.
> >
> > Maybe his problem is he used 5V and did burn out a pin?
> Now that is indeed a possibility.  He talked about a "PPS to GPIO cable"
> in his first post which suggests, to me, that he's not using a Pi Hat
> but some external GPS with the PPS signal routed to GPIO. A Hat with
> integrated GPS would have already had voltage limiters and level
> shifters  to prevent damage.  Many external GPS boards are 5V devices so
> if he wired directly then that GPIO pin could be badly damaged causing
> all sorts of strange issues.
All good ideas, but nope. gps is running off 3.3 votlts and I have 
tested the GPIO pin.

I need to put the gps PPS pin on a scope and see what it is doing.

--
'ooroo

Stinga...(:)-)
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