[sdiy] continuous tuning of analog oscillators

Richie Burnett rburnett at richieburnett.co.uk
Wed Jul 10 23:51:55 CEST 2019


I personally think you'ld do better using those micros to *synthesise* whatever oscillator waveforms you want at the correct pitch, rather than use them to measure the pitch of a sloppy VCO and then calculate the error and try to correct it. But that is a different debate :-)

If you still want to use low cost micros to measure frequencies quickly to a fine resolution then take a look at how laboratory frequency counters work. They use a technique called "reciprocal counting" to time each cycle of the input waveform (or sometimes a bunch of several cycles) against an accurate high speed reference clock in the MHz range.

Using this method they are able to produce frequency readings with many decimal places of resolution even on low frequency input signals without having to measure for a long "gate time" to produce each measurement.

Hope this helps you get started.

-Richie,

Sent from my Xperia SP on O2

---- ulfur hansson wrote ----

>_______________________________________________
>Synth-diy mailing list
>Synth-diy at synth-diy.org
>http://synth-diy.org/mailman/listinfo/synth-diy
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20190710/222eea23/attachment.htm>


More information about the Synth-diy mailing list