At the risk of hijacking a thread, shooting of the subject and just generally 
bad etiquette for news group posting, I am running all my S1 NTP servers on HP 
thin clients!
They only draw ~14 watts of power.
I have managed to fit a 3.5 inch laptop drive in the T150's so they run a 
(minimal text based) full version of centos.

And the serial port seems to be okay:
NTP 1 running of a HP 58534A integrated timing antenna:
State   Remote          Refid   Stratum Type            When    Poll    Reach   
Delay   Offset  Jitter
o       127.127.20.0            GPS     0       Local clock     8       16      
377     0.000   -0.001  0.002   

NTP2 running off an Acutime (hmm, marketing) Gold:
State   Remote          Refid   Stratum Type            When    Poll    Reach   
Delay   Offset  Jitter
*       127.127.29.0            GPS     0       Local clock     2       32      
377     0.000   0.166   0.005   

I Don't know about Load handling, I farm most of the NTP requests off to a 
Stratum 2 (well technically S3 as GPS PPS is not true stratum 1, please correct 
me if I am wrong?)

But works well for me, I'd love to find a ref driver for the Z3805A port 2 even 
second string...
Perhaps using the parse driver w/ PPS refclock (is possible?)

Anyway, there is my 0.02c :p

-marki


-----Original Message-----
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Iain Young
Sent: Tuesday, 2 July 2013 4:14 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] looking for low-power system for gps ntp timekeeping

On 02/07/13 06:43, NeonJohn wrote:

> Before anyone wastes his money on a BeagleBone, I suggest you join the 
> mailing list and read the hundreds of messages each day that pass 
> through, most of them citing problems, mostly with the Linux implementation.
>
> Basically, the ancient implementation of Angstrom Linux is a POS.  
> Just barely enough code to be able to say, for example, that SPI 
> works.  It does - sorta - but not well enough for any application 
> where clock timing or jitter matters.

You are not restricted to just Angstrom. My fleet run Debian. FreeBSD is also 
available. First thing I do is blow away Angstrom from any SD card.

> I had intended to embed the BB white in my next revision induction 
> heater.  After several months of frustration and a considerable amount 
> of money to a kernel programmer to write drivers that actually worked, 
> I gave up.  I could easily had a man-year in the application that I 
> can do bare metal in a few months.

Hmm, is this a case of Angstrom being beind the kernel curve, or is it still an 
issue when running things like Debian ? I've not had the need to use SPI on the 
BB yet, only the Pi.

> The thing that finally canned the BB for me was the short SD card life.
>   Even though the implementation uses a virtualized root file system, 
> it still writes to the SD card about once a second.  The result is 
> that even industrial grade SD cards rarely live over a year.  With the 
> Black they tried to address the problem by putting some NAND memory on 
> board but that only prolongs the problem and with components that are 
> not easily changed.

I've only ever had one SD card go dead on me on my entire fleet, and I suspect 
that was actually my fault, not Debian's :)

  > A final negative is the support.  The team member, a guy named Gerald,
> who provides official support on the mailing lists is one of the most 
> hateful persons I've encountered on the net. No, I never personally 
> had an encounter with him but I daily shook my head in amazement that 
> TI would let such a person rep them.
>

I've heard he can be somewhat robust to deal with. That said, he is very 
knowledgeable from what I've seen/understand. Never actually had to mail the 
mailing list itself though - found all the answers I needed in the archive - 
often from him!

> PS: Before you go to buy the Black, take a careful look at what all 
> they left off in an effort to compete with the Pi.

Hmm. I checked a lot of the things I'd need on the black for this type of 
application, and found they were all still there (Serial Ports, PRUSS, Timers 
etc). Yes you may need to twiddle the pinmux as by default it goes to  he HDMI 
stuff etc, but they are still there

Is there something specific here you are thinking of ? Maybe I just don't need 
what they left off. I do remember looking and going "Meh, not important for 
what I'm doing"


Best Regards

Iain


_______________________________________________
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Reply via email to