[time-nuts] Building a mains frequency monitor

[Chris Albertson]

It works the same on PC hardware

The PPS causes an interrupt and the handler captures the value of a counter
that is driven by the system clock.  It is typically a nanosecond level
clock that just free runs.  It saves the captured value were a user level
process can read it.  The user level process can do whatever it likes it
typically load the captured counter value.  I would not use the syslog time
stamp as that has more lag but for this purpose maybe it is close enough.

The source for Linux PPS has a test program that does exactly the above.

On Fri, Apr 8, 2016 at 10:32 AM, Ben Hall <kd5byb at gmail.com> wrote:

> On 4/6/2016 11:34 PM, Nick Sayer via time-nuts wrote:
>
>> fed into a Raspberry Pi serial port that was running a simple daemon
>> that logged every line it got to syslog. Syslog is handy because it
>> timestamps everything for you and keeps rotating log files and the
>> like.
>>
>
> Would you be so kind as to elaborate how to do this?  Been looking for
> such a solution off and on for a while...and I'm not having a lot of luck
> with Google search at the moment.
>
> thanks much and 73,
> ben
>
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-- 

Chris Albertson
Redondo Beach, California