Re: [AFMUG] OT Raspberry PI

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

Re: [AFMUG] OT Raspberry PI

Subject: Re: [AFMUG] OT Raspberry PI Your other option would be to find a way to setup an internal DMA controller to trigger off of an external input. From your clock source, you would trigger individual DMAs from a static buffer to GPIO connected to some sort of circuit to invert the Mark bits

Re: [AFMUG] OT Raspberry PI

Your other option would be to find a way to setup an internal DMA controller to trigger off of an external input. From your clock source, you would trigger individual DMAs from a static buffer to GPIO connected to some sort of circuit to invert the Mark bits. The DMA controller would loop over the

Re: [AFMUG] OT Raspberry PI

1/4 microsecond is too much jitter? I don't think the pi is going to be your solution. bp On 2/22/2018 5:22 PM, Chuck McCown wrote: I have about 250 nS of jitter on my output signal.

Re: [AFMUG] OT Raspberry PI

: Re: [AFMUG] OT Raspberry PI This calls out for an FPGA solution. On Thu, Feb 22, 2018 at 10:45 PM, Forrest Christian (List Account) <li...@packetflux.com> wrote: You can get a fpga board which might be suitable for this project (after adding appropriate clocks) for around $20 anymore.

Re: [AFMUG] OT Raspberry PI

2018 7:48:19 AM Subject: Re: [AFMUG] OT Raspberry PI Yes, and one would think that Metaswitch would have a 10 MHz input. From: Lewis Bergman Sent: Friday, February 23, 2018 6:44 AM To: af@afmug.com Subject: Re: [AFMUG] OT Raspberry PI Every Rubidium GPS timing piece of gear

Re: [AFMUG] OT Raspberry PI

Yes, and one would think that Metaswitch would have a 10 MHz input. From: Lewis Bergman Sent: Friday, February 23, 2018 6:44 AM To: af@afmug.com Subject: Re: [AFMUG] OT Raspberry PI Every Rubidium GPS timing piece of gear I have ever seen outputs 10MHz. Every device that I have ever seen

Re: [AFMUG] OT Raspberry PI

O, I was googling for cheap fpga but did not find anything that cheap. From: Forrest Christian (List Account) Sent: Thursday, February 22, 2018 9:45 PM To: af Subject: Re: [AFMUG] OT Raspberry PI You can get a fpga board which might be suitable for this project (after adding appropriate

Re: [AFMUG] OT Raspberry PI

wrote: > https://en.wikipedia.org/wiki/ECos > > 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:* R

Re: [AFMUG] OT Raspberry PI

https://en.wikipedia.org/wiki/ECos 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: http://www.ecoscentric.com/news/press

Re: [AFMUG] OT Raspberry PI

1 will be >>>> a D flip flop and a few AND/NAND gates. So that ought to get me super low >>>> jitter. >>>> >>>> Trying for stratum I with rubidium hold-over isochronous performance at >>>> the end of the day. For cheap. >>>>

Re: [AFMUG] OT Raspberry PI

I with rubidium hold-over isochronous performance at >>> the end of the day. For cheap. >>> >>> *From:* Forrest Christian (List Account) >>> *Sent:* Thursday, February 22, 2018 6:27 PM >>> *To:* af >>> *Subject:* Re: [AFMUG] OT Raspberry PI >>

Re: [AFMUG] OT Raspberry PI

. >> >> Trying for stratum I with rubidium hold-over isochronous performance at >> the end of the day. For cheap. >> >> *From:* Forrest Christian (List Account) >> *Sent:* Thursday, February 22, 2018 6:27 PM >> *To:* af >> *Subject:* Re: [AFMUG]

Re: [AFMUG] OT Raspberry PI

th rubidium hold-over isochronous performance at > the end of the day. For cheap. > > *From:* Forrest Christian (List Account) > *Sent:* Thursday, February 22, 2018 6:27 PM > *To:* af > *Subject:* Re: [AFMUG] OT Raspberry PI > > Ok, I think you missed this portion of my e

Re: [AFMUG] OT Raspberry PI

t;> the end of the day. For cheap. >> >> *From:* Forrest Christian (List Account) >> *Sent:* Thursday, February 22, 2018 6:27 PM >> *To:* af >> *Subject:* Re: [AFMUG] OT Raspberry PI >> >> Ok, I think you missed this portion of my email last time: >>

Re: [AFMUG] OT Raspberry PI

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 > *Subje

Re: [AFMUG] OT Raspberry PI

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: http://www.ecoscentric.com/news/press-170314.shtml --bp -- bp part15sbs{at}gmail{dot}com On Thu, Feb 22, 2018

Re: [AFMUG] OT Raspberry PI

er. 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 ther

Re: [AFMUG] OT Raspberry PI

Trying for stratum I with rubidium hold-over isochronous performance at > the end of the day. For cheap. > > *From:* Forrest Christian (List Account) > *Sent:* Thursday, February 22, 2018 6:27 PM > *To:* af > *Subject:* Re: [AFMUG] OT Raspberry PI > > Ok, I think you missed

Re: [AFMUG] OT Raspberry PI

To: af Subject: Re: [AFMUG] OT Raspberry PI Ok, I think you missed this portion of my email last time: "I'm skeptical that you'll be able to generate a bitstream with enough accuracy under Linux, without extreme programming measures. I'd suggest a digilent chipkit wifire and the arduin

Re: [AFMUG] OT Raspberry PI

Ok, I think you missed this portion of my email last time: *"I'm skeptical that you'll be able to generate a bitstream with enough accuracy under Linux, without extreme programming measures.I'd suggest a digilent chipkit wifire and the arduino ide for this. You should be able to bitbang at

Re: [AFMUG] OT Raspberry PI

, February 22, 2018 5:58 PM To: af@afmug.com Subject: Re: [AFMUG] OT Raspberry PI On 2/22/18 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

Re: [AFMUG] OT Raspberry PI

Pi is not that fast when you talk about the gpio. While trying to measure some ac signals i was amazed i could only measure 4 inputs and still get a resolution of .5 amps on each one. On Thu, Feb 22, 2018, 6:59 PM Seth Mattinen wrote: > On 2/22/18 3:36 PM, ch...@wbmfg.com

Re: [AFMUG] OT Raspberry PI

On 2/22/18 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. nice really only helps prioritize (or not) compared to other

Re: [AFMUG] OT Raspberry PI

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 dir

Re: [AFMUG] OT Raspberry PI

How much? From: Colin Stanners Sent: Thursday, February 22, 2018 5:21 PM To: af@afmug.com Subject: Re: [AFMUG] OT Raspberry PI I found these devices that do what you want, but they look fancy and expensive, I'm guessing that you wish to get around the latter. https://www.engageinc.com

Re: [AFMUG] OT Raspberry PI

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 >

Re: [AFMUG] OT Raspberry PI

22, 2018 4:58 PM To: Motorola III Subject: Re: [AFMUG] OT Raspberry PI 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 syn

Re: [AFMUG] OT Raspberry PI

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

Re: [AFMUG] OT Raspberry PI

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

Re: [AFMUG] OT Raspberry PI

: 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

Re: [AFMUG] OT Raspberry PI

C I just ran nice ./blink -20 and it did not seem to change the jitter at all. -Original Message- From: Josh Reynolds Sent: Thursday, February 22, 2018 4:19 PM To: af@afmug.com Subject: Re: [AFMUG] OT Raspberry PI Well, first of all what is your program written in? On Thu, Feb 22

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

Re: [AFMUG] OT Raspberry PI

Well, first of all what is your program written in? On Thu, Feb 22, 2018 at 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

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

Re: [AFMUG] OT Raspberry PI

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-standard-and-real-time-linux

Re: [AFMUG] OT Raspberry PI

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

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-standard-and-real-time-linux-4-9-kernel-2d9c20704495 On Feb 22, 2018 4:48 PM, wrote: > Anyone know how to get my program to run on bare metal?

Re: [AFMUG] OT Raspberry PI

You can change the niceness of the process with the "nice" command. There's preemption in the Linux kernel, but I don't know how to make it happen. -- Original Message -- From: ch...@wbmfg.com To: af@afmug.com Sent: 2/22/2018 5:48:11 PM Subject: [AFMUG] OT Raspberry PI A

[AFMUG] OT Raspberry PI

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