[time-nuts] Very slow freq. counter / event counter

Andrea Baldoni erm1eaae7 at ermione.com
Tue Apr 22 17:33:53 UTC 2014

On Fri, Apr 18, 2014 at 02:48:09PM -0700, Chris Albertson wrote:

> > This chip does what you want: http://leapsecond.com/pic/picpet.htm
> > Input frequency is 0.01 Hz to 100 Hz. Output is microsecond time-stamp and
> > event-count over RS232.

> PCs can do that without the chip.  Connect the pulse to the DCD line of an
> RS232 port and it will get logged with a uSec timestamp.  It works for any
> frequency from maybe 1kHz to 0Hz.
> The port tolerates volts from -12 to +12.    I don't think you need any add
> chip to log pulses.

Hello all, and thank you for the ideas.
I have read here many times about the linux PPS interface, but I never managed
to try it. I use linux as my main OS since 1994 so it's interesting to note
I ought to have tried it before :)
However, and the same could be told about the very interesting picpet, I would
have liked more a self contained solution: you stick two alligator clips and
read numbers, like a DMM.
The HP 5334/5335 Javier and Magnus suggested are a step in the right direction,
but unfortunately, they cannot be found cheaply here in Italy and they are
big for the needs like my Racal Dana 1992.

What are using high school labs to time motion physics experiments?
I remember we had an electromechanical stopwatch with contacts for start and
stop, but it was obsolete already then so they must have something electronic,
or everyone use a PC now? Maybe the educational field has his own very
specific devices.

Best regards,
Andrea Baldoni

More information about the Time-nuts_lists.febo.com mailing list