Re: [time-nuts] precision timing pulse

The PIC can easily be programmed to be armed with a switch and stop at a particular count, or you can use actual logic - debouncer, gating flip-flop and programmable counter! David N1HAC On 11/15/16 1:57 PM, Chuck / Judy Burch wrote: I'm building a laboratory scintillation counter that uses

Re: [time-nuts] Thermal impact on OCXO

Hi Bob, Do you recall if you fitted with true ordinary least squares, or fit with a recursive/iterative approach in a least squares sense. If the aging curve is linearizable, it isn't jumping out at me. If the model was hypothetically: F = A ln( B*t ) F = A ln(t) + Aln(B) which could

Re: [time-nuts] precision timing pulse

Exactly and counting gps seconds may be useful. Anyhow will be curious to see what he is counting. On Tue, Nov 15, 2016 at 9:25 PM, Chris Albertson wrote: > The PicDiv does something not needed for this use case. It produces a > nice usable output frequency. You don't need that, you only nee

Re: [time-nuts] precision timing pulse

I'll add my 10 cents here. Because the accumulation time can be very long 555 class timers become a serious issue due to the large R&Cs involved. I will guess some accuracy is desired. As Chris says a start button to an arduino. The difference I might suggest is a GPS 1sec PP into the arduino for c

Re: [time-nuts] precision timing pulse

The PicDiv does something not needed for this use case. It produces a nice usable output frequency. You don't need that, you only need to know when X number of cycles have completed. It is an order of magnitude simpler problem.Just count to X then stop, that's it. On Tue, Nov 15, 2016 at

Re: [time-nuts] precision timing pulse

If you are trying to avoid writing code, the 74hc might be worth taking a look at. On Tue, Nov 15, 2016 at 3:00 PM Chuck / Judy Burch wrote: > > I'm building a laboratory scintillation counter that uses my HP 5335a > counter as a read-out. The FREQ mode gives only approximate results > (max

Re: [time-nuts] precision timing pulse

So you are already using a micro controller (a PIC) then 1) for the button input use an unused pin on the PIC. Connect the pin to 5V via a 10K resister and then when you press the button it shorts the pin to ground.The PIC then starts counting. A modern uP has the 10K resister build into th

Re: [time-nuts] precision timing pulse

The author of PicDiv publishes the ASM code for his dividers. If fluent in assembley(er) it's probably quite doable. Many of the examples have a ARM or SYNC feature http://www.leapsecond.com/pic/picdiv.htm -=Bryan=- From: time-nuts on behalf of Hal Murray

Re: [time-nuts] precision timing pulse

You could build a simple one shot using something like a 555 timer IC Or take a input pin from your PiC and use the RTC to drive a routine which changes state of the pin for the duration of test Content by Scott Typos by Siri > On Nov 15, 2016, at 1:57 PM, Chuck / Judy Burch > wrote: > > >

Re: [time-nuts] precision timing pulse

ciandjabu...@gmail.com said: > How do I get a pulse to start with a push button and then stop for example > 500 or 10,000 seconds later? How about another PIC? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.

[time-nuts] precision timing pulse

I'm building a laboratory scintillation counter that uses my HP 5335a counter as a read-out. The FREQ mode gives only approximate results (maximum gate time is about 5 seconds). The TOT mode counts pulses for an arbitrary time that can be set using the "external arm input" on the rear panel