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 that takes a timing signal requires 10MHz. I probably have lead a sheltered life but I haven't seen anything else. On Fri, Feb 23, 2018 at 12:06 AM Robert <i...@avantwireless.com> 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:* 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 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-standard-and-real-time-linux-4-9-kernel-2d9c20704495 >>> <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, <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. >> >> -- >
