On 2/22/18 5:52 PM, Chuck McCown wrote:
That looks great.  Did not find a cost anywhere.
*From:* Bill Prince
*Sent:* Thursday, February 22, 2018 6:47 PM
*To:* Motorola III
*Subject:* Re: [AFMUG] OT Raspberry PI
Try this:

On Thu, Feb 22, 2018 at 3:56 PM, Bill Prince <> wrote:

    Pretty sure you need  RTOS to accomplish this.That will get pretty
    close to bare metal.

    On Thu, Feb 22, 2018 at 3:36 PM, <> wrote:

        Had the command syntax wrong.
        But got nice to work.  Have to sudo if you use negative nice
        It made zero difference in my jitter.  I went from 19 to –20 on
        nice and no change.
        *Sent:* Thursday, February 22, 2018 4:29 PM
        *Subject:* Re: [AFMUG] OT Raspberry PI
        The problem is there is a crap ton of stuff out there that needs
        network sync.  And it all has a T1 as an input.
        But most T1 trunking circuits are getting replaced with SIP.
        So, I am building a cheap and dirty T1 signal generator that is
        GPS and rhubidium referenced.  The hard part is easy.  The easy
        part should be easy but all the T1 framing chips that used to
        exist no longer exist.
        The ones that are out there have massive CPU interfaces and tons
        of registers that need to get set to get them fired up and
        Where is Exar when you need them....
        *From:* Adam Moffett
        *Sent:* Thursday, February 22, 2018 4:21 PM
        *Subject:* Re: [AFMUG] OT Raspberry PI
        Tell whoever's got the T1 that 1967 is way behind us and get a
        new interface.
        Problem eliminated LOL
        ------ Original Message ------
        Sent: 2/22/2018 6:16:45 PM
        Subject: Re: [AFMUG] OT Raspberry PI
        I have to generate an alternate mark inversion signal on 1.544
        MHz with every 193rd bit following a t1 framing sequence.
        Sure wish a 555 could do that.
        *From:* Dave
        *Sent:* Thursday, February 22, 2018 4:10 PM
        *Subject:* Re: [AFMUG] OT Raspberry PI
        Find a 555 timer ... I used many in the olden day when
        radioshacks were king LOL!

        On 02/22/2018 05:05 PM, wrote:
        I am thinking of using some shift registers instead of using
        the PI output directly as the timing signal.
        Use the PI to load them.
        I love me some hardware design anyhow....
        *From:* Colin Stanners
        *Sent:* Thursday, February 22, 2018 3:59 PM
        *Subject:* Re: [AFMUG] OT Raspberry PI
        Other than setting the process priority, you may need a
        custom kernel. See

        On Feb 22, 2018 4:48 PM, <> wrote:

            Anyone know how to get my program to run on bare metal?
            Or at the very least tell Linux that my program is the
            most important thing in the world and service it above
            all other things.
            I am trying to create a timing signal with the Pi.  It is
            doing it but the jitter is pretty bad.
            I have researched trying to use an interrupt but there is
            a pretty low limit on how many times per second you can
            fire a hardware interrupt.
Too low for my application.


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