Try this: http://www.ecoscentric.com/news/press-170314.shtml
--bp
--
bp
part15sbs{at}gmail{dot}com
On Thu, Feb 22, 2018 at 3:56 PM, Bill Prince <part15...@gmail.com> wrote:
> Pretty sure you need RTOS to accomplish this.That will get pretty close
> to bare metal.
>
> -bp
>
> --
> bp
> part15sbs{at}gmail{dot}com
>
> On Thu, Feb 22, 2018 at 3:36 PM, <ch...@wbmfg.com> wrote:
>
>> Had the command syntax wrong.
>> But got nice to work. Have to sudo if you use negative nice numbers.
>>
>> It made zero difference in my jitter. I went from 19 to –20 on nice and
>> no change.
>>
>> *From:* ch...@wbmfg.com
>> *Sent:* Thursday, February 22, 2018 4:29 PM
>> *To:* af@afmug.com
>> *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 running....
>>
>> Where is Exar when you need them....
>>
>> *From:* Adam Moffett
>> *Sent:* Thursday, February 22, 2018 4:21 PM
>> *To:* af@afmug.com
>> *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 ------
>> From: ch...@wbmfg.com
>> To: af@afmug.com
>> 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
>> *To:* af@afmug.com
>> *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, ch...@wbmfg.com 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
>> *To:* af@afmug.com
>> *Subject:* Re: [AFMUG] OT Raspberry PI
>>
>> Other than setting the process priority, you may need a custom kernel.
>> See https://medium.com/@metebalci/latency-of-raspberry-pi-3-on-s
>> tandard-and-real-time-linux-4-9-kernel-2d9c20704495
>>
>>
>> On Feb 22, 2018 4:48 PM, <ch...@wbmfg.com> 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.
>>>
>>
>> --
>>
>>
>
