$250ish gets you a 6core ARM and fpga with 4 gig ports anymore On Feb 22, 2018 7:42 PM, "Lewis Bergman" <lewis.berg...@gmail.com> wrote:
> They aren't cheap but you could always use an fpga. > > On Thu, Feb 22, 2018, 7:35 PM Chuck McCown <ch...@wbmfg.com> wrote: > >> No, I saw it, but I already had the Pi so I ignored it and hoped for the >> best. >> I tried it first with arduino. Just not enough speed. And it had the >> jitter problem too. >> >> I have a method using three TTL/CMOS chips that is going to work... I >> think... >> >> The only thing separating the gps disciplined signal and the T1 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. >> >> *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: >> >> >> *"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 least a T1 with this processor (500mhz)"* >> >> Generally the raspberry pi is great for 'tiny server stuff', or 'user >> interface' stuff, and the arduino and/or microcontrollers will work better >> for what you're looking at, since there isn't an operating system in the >> way. All arduino really is is a c++ ide with some simplified libraries. >> >> The wifire product I mentioned is really a PIC32MZ dev board, optimized >> for arduino. If you've had enough of the arduino ide, you can download the >> microchip ide and program it with a full development kit. >> >> Honestly for what you are talking about a EUSART in even a low end PIC >> might be able to handle this. If you program the EUSART into synchronous >> mode you'll just have to stuff a byte into it every 8 bit times and it will >> clock it out for you. Not sure if the clock rate is adjustable enough for >> you, but if you get a PIC with the NCO peripheral you might be able to >> dynamically adjust the frequency enough to make it work. >> >> NCO app sheet: http://ww1.microchip.com/downloads/en/AppNotes/ >> 90003131A.pdf >> >> >> >> >> On Thu, Feb 22, 2018 at 3:48 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. >>> >> >> >> >> -- >> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >> <https://maps.google.com/?q=3577+Countryside+Road,+Helena,+MT+%0D+59602&entry=gmail&source=g> >> forre...@imach.com | http://www.packetflux.com >> <http://www.linkedin.com/in/fwchristian> >> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >> >>
