On Thu, 02 Feb 2012 15:05:49 -0500 "Daniel Schultz" <[email protected]> wrote:
> I found this homebrew GPS receiver project recently: > > http://www.holmea.demon.co.uk/GPS/Main.htm > > No custom specialized chips that are unavailable in small quantities, or which > will go obsolete in a few months. I think the best solution for the open > source GPS community is to design open source receivers with commodity parts > that won't be discontinued in the near future, or for which another commodity > part can be substituted if need be. Maybe somebody can extend this design with > a 2-bit ADC on the end (not me, too many projects here already...) This page went over this list a couple of weeks ago. And actually, i marked it as "use as reference desgin" :-) Also a very interesting design is the one in [1], which is a mostly discrete build GPS/GLONASS receiver. The only integrated components are the PLL, a 10MHz integrated amplifier and a 68k CPU (plus necessary logic, ram, rom around it). Desgning a heterodyne receiver like this (actually super heterodyne as the last "mixing" stage is in software) is "easy". At least today. electronic components working in the GHz range are available for a couple of bucks at single quantities like mixers (eg LT5560, ~3USD), PLLs with integrated VCO's (ADF4350, ~7USD, or LMX2531, ~14USD). Not to mention ADC's with sampling rates as high as 200Msps for just 16USD (ADC08200). All you have to do is find appropriate devices, read the data sheet, apply a fair bit of brain and you get a working design. I know that even a couple of years back, electronic engineers would have killed for these devices that are available to us. Attila Kinali [1] http://lea.hamradio.si/~s53mv/navsats/theory.html -- Why does it take years to find the answers to the questions one should have asked long ago? _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
