[ntp:questions] CHU gadget box files

Tim Shoppa shoppa at trailing-edge.com
Mon Dec 7 17:01:45 UTC 2009

On Dec 6, 3:31 pm, jimmyterrence <jimmyterre... at gmail.com> wrote:
> On a related note, is there anyone using the gadget box, or are you
> just using CHU audio drivers? I was wondering if it would be possible
> to build just the PPS part of the circuitry and use a generic PPS
> driver with the CHU AUDIO driver.

Some folks like to tinker with (and I have myself done so) a PPS
source from one refclock, and a serial stream from a second refclock
under development, as this lets you get a handle on latency etc. This
is how I measured the audio driver latency and jitter using different
tweaks. I think this is a fine cross check.

I didn't actually build "the gadget box" but I just strung together a
LS123, a blinky LED, and a MAX232 in a nearly identical configuration.

Other folks use far cruder TTL to EIA converters (e.g. a diode and a
resistor or similar, taking advantage of the bias commonly found on PC-
clone serial ports.)


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