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Stopwatch functionality
02-06-2019, 02:50 PM
Post: #1
Stopwatch functionality
Is it true that there is not yet a stopwatch for the prime?

Just asking before I try to write one!
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02-06-2019, 04:06 PM
Post: #2
RE: Stopwatch functionality
It is easy to write. It will not be accurate however.

TW

Although I work for the HP calculator group, the views and opinions I post here are my own.
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02-06-2019, 04:29 PM (This post was last modified: 02-06-2019 04:40 PM by StephenG1CMZ.)
Post: #3
RE: Stopwatch functionality
Before you write one...
There is a very simple timer included within my ZIPP program, but it might suffice for timing an event.
http://www.hpmuseum.org/forum/thread-4981.html

Stephen Lewkowicz (G1CMZ)
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02-06-2019, 04:36 PM
Post: #4
RE: Stopwatch functionality
(02-06-2019 04:06 PM)Tim Wessman Wrote:  It is easy to write. It will not be accurate however.

Does anyone use a calculator stopwatch for accuracy? 8^)
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02-06-2019, 04:39 PM
Post: #5
RE: Stopwatch functionality
(02-06-2019 04:29 PM)StephenG1CMZ Wrote:  Before you write one...
There is a very simple timer in my ZIPP program
http://www.hpmuseum.org/forum/thread-4981.html

Thanks.
You might want to include a list of the functionality. I searched the Prime software forum for "stopwatch" and got no hits.
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02-06-2019, 04:42 PM
Post: #6
RE: Stopwatch functionality
(02-06-2019 04:06 PM)Tim Wessman Wrote:  It is easy to write. It will not be accurate however.

The system date/time must be based on a more accurate RTC. I could do a long term correction based on that.
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02-07-2019, 06:25 AM
Post: #7
RE: Stopwatch functionality
Hello,

Time/Date functions should be relatively accurate. But has a 1s granularity.

Ticks is much less accurate, but has a ~ms granularity.

From memory, both on G1 and G2, any drifts in Ticks should be consistent on a given unit at a given temperature. So, a good strategy would be to:
When user hits start: call ticks.
As time progresses, monitor "time". On a second change, take the ticks...
When the user hits stops, call ticks.
Take the first and last second change ticks. Use it to calculate the number of ticks per second. Do the ratio.

Cyrille

Although I work for the HP calculator group, the views and opinions I post here are my own. I do not speak for HP.
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02-07-2019, 07:47 PM
Post: #8
RE: Stopwatch functionality
Good idea, thanks Cyrille!
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