Timeline for Calculate absolute time based on cycles and RTC
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
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| Jun 17, 2020 at 8:21 | history | edited | CommunityBot |
Commonmark migration
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| May 3, 2017 at 18:20 | comment | added | James Waldby - jwpat7 | EB, yes. Great exposition; I'd upvote your answer again if I could. | |
| May 3, 2017 at 18:13 | comment | added | Edgar Bonet | @JamesWaldby-jwpat7: Added some options for the PLL algorithm. That was a looong digression... | |
| May 3, 2017 at 18:12 | history | edited | Edgar Bonet | CC BY-SA 3.0 |
+ options for PLL implementation.
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| May 1, 2017 at 20:07 | comment | added | James Waldby - jwpat7 |
EB, I misunderstood part of your answer and withdraw most of my comment. It isn't clear to me what control the PLL will vary, what its resolution is, etc. Perhaps in your answer you could show a typical PLL-corrected time = ... calculation.
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| May 1, 2017 at 19:44 | comment | added | Edgar Bonet | @JamesWaldby-jwpat7: I don't understand your comment “[...] can keep time at perhaps one part per thousand”. A properly implemented PLL has exactly zero long term drift (it keeps time at zero parts per million), with only short term variations (phase noise) which depend on the clocks and the PLL time constant. One part in 12500 is 80 ppm, very crude compared with the 4 ppm resolution you get using input capture. | |
| May 1, 2017 at 16:20 | history | edited | Edgar Bonet | CC BY-SA 3.0 |
Fixed misspelling.
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| May 1, 2017 at 15:33 | comment | added | James Waldby - jwpat7 | The approach of adjusting the drift count due to 6250+ deviation can keep time at perhaps one part per thousand. However, adjusting the TOP value would allow correction in increments of about one part per 12500. In other words, the value loaded into OCR1A should slowly change, over a period of minutes or hours, to produce correct interrupt rate. | |
| May 1, 2017 at 15:23 | history | edited | Edgar Bonet | CC BY-SA 3.0 |
Fixed misspelling.
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| May 1, 2017 at 15:22 | history | edited | Edgar Bonet | CC BY-SA 3.0 |
Fixed misspelling.
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| May 1, 2017 at 12:51 | history | answered | Edgar Bonet | CC BY-SA 3.0 |