Mr. Sproul: I really like your solution! Do you mind emailing me code and schematics?
Bob, you right: I should be watching slips with a PPS-actuated buffer. For now, I don't have the resources for a ready-made dual-input counter, but the strangest/best things seem to show up at the flea market when I'm least expecting them ;) For now, I will be conducting research on integrating a rudimentary counter on top of Mr. Sproul's design. Chris: It should be no issue to take your comparator and 'tape' an A/D pin to it for digital monitoring, either (I'm not sure how Bob's design is implemented, but it appears roughly equivalent). Do you have any examples I should be looking for? -CH Chris Hoffman [email protected] http://ar.ctur.us On Jul 17, 2012, at 11:51 AM, MSproul wrote: > > On Jul 17, 2012, at 11:09 AM, Chris Hoffman, KG6O wrote: > >> >> What advice does anyone have on building/finding cheap [visual?] comparison >> devices to display or detect a timing [lesajo?] from my 10MHz sine wave >> ports? >> I am thinking about building an embedded system to automate monitoring, >> configuration, and alerts... perhaps using an Arduino. >> >> -CH__ > > > > > > Hi Chris > I am doing what you are asking about. I have built a Frequency Comparator > that compare two10 MHz > square waves but would probably work with sine waves. I am using a Digilent. > Inc. chipKIT Uno32. > > > http://digilentinc.com/Products/Detail.cfm?NavPath=2,892,893&Prod=CHIPKIT-UNO32. > > This board is comparable to the Arduino and most of the shields for the > Arduino will work with the chipKIT. > To program the chipKIT requires the Mpide program from Digilent. The program > is free (from the above site) > AND will program both the Arduino and chipKIT, just select the proper option. > No change in source code is required > to compile for the Arduino or chipKIT. The program looks just like the one > from Arduino. > > The attached photo shows the display of my comparator. > > The first line is the name of the source code > The second line is error between reference and Device under Test and whether > the DUT is high or low > The third line is current time between cycle slips > The fourth line is the current error and is continually updated during a > cycle slip > > The LEDs at the top give a visual presentation of the cycle slips: > Left-moving - DUT is LOW., > right-moving - the DUT is HIGH > > The hardware only requires 6 ICs plus LEDs and a few passive parts. > > The program is not finished yet. I still have to do some long-term testing > and some minor 'tweaking" > but does what I want. > > It is very interesting to watch an oscillator from a cold start. The lights > will race one direction, slow down, > stop, then race the other direction until it finally slows down and stops. > > M. L. Sproul, W5UGQ > Amarillo, TX > [email protected] > > <FreqComp.JPG> _______________________________________________ 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.
