Most of the "free" tool chains are not truly free I.e. open source including all libraries and coupled with an open source compiler and debugger. In addition few of them are currently offered in hobbyist friendly DIP packages. Once you resign yourself to having to build hardware glue for some of the special functions required, CPU performance becomes mostly a non issue. For quick and dirty lash ups on perf board (as I believe the OP is looking for), It's hard to beat a pic or Avr and for code re-use from a large online community it's hard to beat the arduino eek-o-system Dale Sent from my iPhone
On Dec 6, 2012, at 1:00 PM, "Bob Camp" <li...@rtty.us> wrote: > Hi > > It's a rare microcontroller these days that does *not* come with a free tool > chain. Same goes for the debugger. Most MCU lines have family members with > similarly low (or lower) prices and good availability. They pretty much all > either work with a crystal two caps and a resistor. Most will run fine with > none of the above on the internal clock. > > Bob > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Dale J. Robertson > Sent: Thursday, December 06, 2012 12:45 PM > To: time-nuts@febo.com > Subject: Re: [time-nuts] GPSDO Alternatives > > Arduino is Dirt Cheap! > At it's cheapest it is just an atmel AVR, a crystal, 2 caps and a resistor > with the arduino bootloader programmed into it. Easily obtainable from > several sources for 5 bucks or so. All the code, toolchain etc. (the > ecosystem as it were) is free. it's real easy to put one together on a piece > > of perfboard. If you're gonna put the phase detector, dividers etc. together > > anyway there's really no need to clutter things up with some ginormous > commercial arduino board. > Dale > > -----Original Message----- > From: Keenan Tims > Sent: Thursday, December 06, 2012 10:38 AM > To: time-nuts@febo.com > Subject: Re: [time-nuts] GPSDO Alternatives > > As a lurker, I just want to chime in and say that I for one would love > to see an open-source GPSDO implementation. There are quite a few open > hardware designs out there, but as Bob suggests, all the interesting > bits are tied up in the closed-source software they run. And most of > them are no longer maintained, meaning it's getting hard to find parts. > > I've thought on designing a hardware platform to support a GPSDO as > well, but don't have the time-nut or control theory skills (or > equipment) necessary to make the software any good. My hope at the time > was that a build it and they will come approach would solve those > problems, but I haven't had time to make that gamble. > > As far as uP choice, Arduino's only saving grace is the pool of existing > 'developers' in the amateur community for it - but that's perhaps a big > deal here. It's expensive, doesn't include debug hardware, and is slow > with not many peripherals. I'd second the STM32 ARM Cortex platform, or > suggest MSP430 if you want to stay cheap and slow. > > Keenan > VE7XEN > > On 2012-12-06 1:28 AM, Chris Albertson wrote: >> On Wed, Dec 5, 2012 at 2:50 PM, <saidj...@aol.com> wrote: >>> >>> If there is one thing I learned, it is that one is never finished >>> improving >>> the software. That is why we are time-nuts I guess. >> This is the reason I suggested using the Arduino. It is so easy to >> program >> that MANY people will be able to contribute. That is my goal, a GPSDO >> that >> can be a "living project" that is not dependent on one or a few experts. >> I'd like to see a budget of well under $100, again so that more people can >> contribute and experiment. >> >> A design that can evolve will have just about any performance people want. >> So don't worry about if it is 1E-12 or 1E-15. Just make it transparent >> and easy to understand and modify. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
