I believe this was a major part of the improvements in android
On 2/22/18 3:58 PM, Bill Prince 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
<mailto: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.
--
