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 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. --
