Author Topic: Davis still using the CC1021 in current VP2 and/or VUE hardware?  (Read 2834 times)

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Offline Old Tele man

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Re: Davis still using the CC1021 in current VP2 and/or VUE hardware?
« Reply #50 on: January 18, 2018, 02:38:01 PM »
So, does, anybody know what "clock" chip the two consoles use? Same device or different? Is the same device used for internal timing, or are separate clocking sources used?

I raise this question because my experience has been that my VP2 console clock timing was terrible (always losing time) while the replacement VUE console clock seems to be quite accurate.
« Last Edit: January 18, 2018, 02:44:12 PM by Old Tele man »
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX1 Precision Digital Barograph
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline rdsman

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Re: Davis still using the CC1021 in current VP2 and/or VUE hardware?
« Reply #51 on: January 18, 2018, 03:07:27 PM »
So, does, anybody know what "clock" chip the two consoles use? Same device or different? Is the same device used for internal timing, or are separate clocking sources used?

I raise this question because my experience has been that my VP2 console clock timing was terrible (always losing time) while the replacement VUE console clock seems to be quite accurate.

There isn't a real time "clock" chip in either console.  The processor keeps time with a clock crystal.

Ray

Offline Old Tele man

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Re: Davis still using the CC1021 in current VP2 and/or VUE hardware?
« Reply #52 on: January 18, 2018, 03:20:27 PM »
So, does, anybody know what "clock" chip the two consoles use? Same device or different? Is the same device used for internal timing, or are separate clocking sources used?

I raise this question because my experience has been that my VP2 console clock timing was terrible (always losing time) while the replacement VUE console clock seems to be quite accurate.

There isn't a real time "clock" chip in either console.  The processor keeps time with a clock crystal.
A raw crystal? Usually there's a divide-by-N "chip" used to derive the desired 'clock' timing.
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX1 Precision Digital Barograph
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline rdsman

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Re: Davis still using the CC1021 in current VP2 and/or VUE hardware?
« Reply #53 on: January 18, 2018, 03:59:07 PM »
So, does, anybody know what "clock" chip the two consoles use? Same device or different? Is the same device used for internal timing, or are separate clocking sources used?

I raise this question because my experience has been that my VP2 console clock timing was terrible (always losing time) while the replacement VUE console clock seems to be quite accurate.

There isn't a real time "clock" chip in either console.  The processor keeps time with a clock crystal.
A raw crystal? Usually there's a divide-by-N "chip" used to derive the desired 'clock' timing.

See:

http://ww1.microchip.com/downloads/en/AppNotes/Atmel-1259-Real-Time-Clock-RTC-Using-the-Asynchronous-Timer_AP-Note_AVR134.pdf

Ray

Offline Old Tele man

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Re: Davis still using the CC1021 in current VP2 and/or VUE hardware?
« Reply #54 on: January 18, 2018, 06:05:47 PM »
So, does, anybody know what "clock" chip the two consoles use? Same device or different? Is the same device used for internal timing, or are separate clocking sources used?

I raise this question because my experience has been that my VP2 console clock timing was terrible (always losing time) while the replacement VUE console clock seems to be quite accurate.

There isn't a real time "clock" chip in either console.  The processor keeps time with a clock crystal.
A raw crystal? Usually there's a divide-by-N "chip" used to derive the desired 'clock' timing.

See:

http://ww1.microchip.com/downloads/en/AppNotes/Atmel-1259-Real-Time-Clock-RTC-Using-the-Asynchronous-Timer_AP-Note_AVR134.pdf
Yep, that's what the industry calls a Real Time Clock (RTC) chip. The external "oscillator" is a crystal that is oscillating at many, many, many times faster than the end/desired "clock" output...typically about 10X faster but can vary. The greater the difference between the oscillator input and the clock output, the tighter the operating tolerance (less variance).
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX1 Precision Digital Barograph
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline LABob

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Re: Davis still using the CC1021 in current VP2 and/or VUE hardware?
« Reply #55 on: January 20, 2018, 08:51:42 AM »
Yep, that's what the industry calls a Real Time Clock (RTC) chip. The external "oscillator" is a crystal that is oscillating at many, many, many times faster than the end/desired "clock" output...typically about 10X faster but can vary. The greater the difference between the oscillator input and the clock output, the tighter the operating tolerance (less variance).

Sorry to be a little OT, but is this why some clocks drift a couple of minutes a week vs. some that can drift less than a second per week? I've always figured that products with a super inaccurate clock were a sign of corner cutting on other electronic components as well.