[ntp:questions] Do I have a lock to my NMEA GPS?

Terje Mathisen "terje.mathisen at tmsw.no" at ntp.org
Mon Nov 12 16:45:16 UTC 2012

Ralph Aichinger wrote:
> Terje Mathisen <"terje.mathisen at tmsw.no"> wrote:
>> I.e. the maximum power of the Sure GPS is 0x32 or 50, corresponding to
>> the 100 mA which is guaranteed by the USB 1.0 spec. :-)
> This is good news for anybody using the Raspberry Pi.
> So is it actually possible to power the Sure GPS from the Pi USB
> port in practice, as long as the power supply has enough current
> for 700mA (the Pi itself)+100mA? Does that really work, has anybody
> tried?

I would be willing to (make a small) bet that the Pi has to support up 
to the 500 mA of the 2.0 spec, simply because there are so many 
peripherals, particuarly USB disks, that require this in order to work 
at all.

OTOH, it has to depend on the Pi power supply being big enough. Is there 
a wall wart or similar in the kit?


- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

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