[ntp:questions] ESR looking for good GPS clocks
nomail at example.com
Tue Mar 6 09:45:24 UTC 2012
unruh <unruh at invalid.ca> wrote:
> He is suggesting that the on board gps chip have ntp on board, so that
> your computer timestamps the request, the gps chip then timestamps when
> that trequest was received and returns it. No gps chip that I know of
> has an onboard ntp server. So if you want to get a chip fab to make you
> a special purpose chip which contains a gps receiver and ntp onboard,
> you could probably do it-- but it might cost a bit more than $100 ieach
> lots of 100.
Of course not. NTP is software, not hardware.
The only thing you need is special firmware for any existing GPS chip
that includes the NTP functionality you want, and maybe drops some other
functionality to make room in the flash.
Some manufacturers provide a software development kit that allows the
user to write his own code, link that with the object modules written
by the manufacturer, and create a new flash file for the GPS device.
At least SiRF provides such a development kit to its commercial customers.
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