Well, I do everything in PICs with a assembler, but you have a point. A flash memory chip is one route. An FTDI Vinculum and USB memory stick, another. Andy www.g4jnt.com
On Wed, 24 Feb 2021 at 14:05, Dan Kemppainen <[email protected]> wrote: > Andy, > > Perhaps one of the little openlog units from sparkfun, or one of the > clones would work for logging? > > https://www.sparkfun.com/products/13712 > > Honestly, I have two and a pair of 32Gb Cards, but have not tried them > yet. Seems like a good solution for a project like this. I don't know > how they buffer writes to the microSD, or what the write life on an > SDcard would be like. > > Dan > > > On 2/24/2021 7:35 AM, [email protected] wrote: > > > > My monitor uses a 16F628A PIC device clocked from a 10MHz TCXO. 50Hz > > mains is fed to the capture/compare module which is set to measure the > > number of periods of the prescaled clock in every fourth cycle of the > > mains. A simple integer division and the answer is the mains frequency > in > > milliHz units.. I only measure to about 0.002Hz resolution as the > > variation is so wide (~~ 0.2Hz RMS) this is quite enough . > > Completely separately, a four bit counter is incremented by this divided > > mains signal every 80ms, and also decremented every 80ms by the divided > > down clock. Software is written so that increment and decrement cannot > > clash. > > > > The result is a 32 bit twos-complement count, to 80ms resolution, of > mains > > timing difference from that of the TCXO. A bit of arithmetic and the > > answer can be shows as a timing discrepancy in seconds on the display. > > > > It would be a matter of just a few minutes of extra code writing to add a > > serial output to transfer data to a logger . Which I may yet do, but > that > > would require getting an old laptop out of storage and leaving it on 24/7 > > to do the logging - don't keep my main PCs on continuously. > > > > Not sure this list passes-through attachments; if not the oicture is > here > > http://www.g4jnt.com/DropF/img2783.JPG > > > > Andy > > www.g4jnt.com > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
