Elapsed Timer Demo

[shahidali55]

Hi Darrel,
Some where Josepino had mentioned on his site that he had used Roman Black's one_sec.asm routine in his clocks (maybe he mentioned this by accident).
I tried making a similar program in PBP but had no success, till now.
Finally i got the progam running. its the exactly same one_sec.asm routine running with instant interrupts, and guess what,... it worked, and really accurately...
Its even more accurate than the Elapsed Timer...
I'll post the code so that it may be useful for someone...
(I'm not as mean and selfish as Josepino...
and thanks a lot for the instant interrupts program...
Chiao...

[Leonardo]

Hello shahidali55,

It can publish or to send to my mail [email protected] the code and complete circuit since is very interesting its project, congratulations for its idea!.

Leonard

Regards

Hi Darrel,
Some where Josepino had mentioned on his site that he had used Roman Black's one_sec.asm routine in his clocks (maybe he mentioned this by accident).
I tried making a similar program in PBP but had no success, till now.
Finally i got the progam running. its the exactly same one_sec.asm routine running with instant interrupts, and guess what,... it worked, and really accurately...
Its even more accurate than the Elapsed Timer...
I'll post the code so that it may be useful for someone...
(I'm not as mean and selfish as Josepino...
and thanks a lot for the instant interrupts program...
Chiao...

[Darrel Taylor]

shahidali55,

Pardon my stubborness!
Sometimes I get so defensive, I don't recognize when someone knows better.

I've tried your code, and there's definately a big difference.

But now, I must know how much, and more importantly why.

Fortunately, with Instant Interrupts, it was easy to combine both timers into one program, and I'm running it on a telnet server, in case you (or anyone else) wants to see too.   I started the test at 12:15 am PST, and have set the time as close as possible relative to GMT. This screen capture was 30 seconds later.




If you have Hyperterminal installed you can see the results by using the TimerTest.ht file in the .zip below. Hopefully in a few days the error will be more evident. T1 is the Elapsed timer, and T0 is your new timer.

password: guest
then type data and press enter
<br>
Here's a reference time http://nist.time.gov/timezone.cgi?Pacific/d/-8/java
Although i started about 1/2 second late.
<br>

Test completed. .zip file removed.

[Leonardo]

Hello, I have not managed to compile I cosay give errors me, can help me please.

Thanks

Leonard

shahidali55,

Pardon my stubborness!
Sometimes I get so defensive, I don't recognize when someone knows better.

I've tried your code, and there's definately a big difference.

But now, I must know how much, and more importantly why.

Fortunately, with Instant Interrupts, it was easy to combine both timers into one program, and I'm running it on a telnet server, in case you (or anyone else) wants to see too. &nbsp; I started the test at 12:15 am PST, and have set the time as close as possible relative to GMT. This screen capture was 30 seconds later.



If you have Hyperterminal installed you can see the results by using the TimerTest.ht file in the .zip below. Hopefully in a few days the error will be more evident. T1 is the Elapsed timer, and T0 is your new timer.

password: guest
then type data and press enter
<br>
Here's a reference time http://nist.time.gov/timezone.cgi?Pacific/d/-8/java
Although i started about 1/2 second late.
<br>

[shahidali55]

Hi Leonard,
To compile this code you need to have Darrel's Instant interrupt file (DT_INTS-14.bas) in the folder along with the source code...
You also need to have enabled the "Use MPASM" option in the compile and options menu...

[Leonardo]

Hello,

Don't I find the "DT_INTS-14.bas" in none of the folders, can send it please to my mail?. [email protected]

Thank you

Hi Leonard,
To compile this code you need to have Darrel's Instant interrupt file (DT_INTS-14.bas) in the folder along with the source code...
You also need to have enabled the "Use MPASM" option in the compile and options menu...

[Darrel Taylor]

Hmmm,

I fully expected the test to show that the new timer would keep accurate time and give a good indication how far off the Elapsed Timer was, but instead after 24hrs, the Elapsed Timer (T1) was still within 1 second of actual time, and the new timer (T0) had gained almost 8 seconds. Also, my PC's clock was 3 seconds slow. (interesting, but not relevant)<br>
<br>
Since then, I've turned Roman's routine into a subroutine and ran it in loops just to verify it's counting, and can say that it does accuratly count 1 million instructions per second. &nbsp; Well, actually, it counts 3 seconds at 999,936 instructions and every 4th second at 1,000,192. Which over the 4 seconds averages out to exactly 4,000,000 instructions. So in a perfect world, with a 4.000000mhz crystal, it should count perfect time. But it doesn't. (in my case)

This leads me to beilieve that My crystal is off.
So, continuing with with the perfect world theory...

There's 86,400 seconds per day
or 86,400,000,000 instructions per day

an additional 8 seconds is 8,000,000 instructions
for a total of 86,408,000,000

that divided by the 86,400 seconds per day gives
1,000,092.593 instructions per day or a freq. of
4,000,370.37 hz.

That's 93PPM off center frequency. So I've either got a crystal that's almost twice the tolerance. OR I'm still missing something big time.
<br>

[SteveB]

Darrel,
This may be stating the obvious, but either:
1) Both timer routines are accurate (Definitely not true)
2) T0 is accurate, T1 is not
3) T1 is accurate, T0 is not
4) Neither timer routine is accurate (if your Xtal is within specs and running fast, T0 runs fast and T1 runs slow, this could explain the results you have shown)

The Xtal error needs to be eliminated to see what’s happening with the last three. One suggestion may work. If you have a RTC handy that will output the 32768Hz, use this as an input to the timers. Then, you can compare the PIC clocks against RTC, all of which would be running at the same exact freq. Some tweeking of the code will be required for this. Also, This may lead to changes in the code which would mask the errors occurring with the 4Mhz Xtal, but it may be worth a try.
I have actually done this with a timer routine similar to the Elapsed timer, and it works fine. I will add it to this post when I get back to my home computer (Found it! Elapsed_Timer_INT_32.bas.txt). It has some significant differences though. It never stops the timer, only adds to the TMRxH byte, and counts 128 "ticks" per second. (edit: I also count DOWN. I think this added some efficiency with the ASM, but can't remember off the top of my head. It's run on an 18F4620)

The other is to get a measure of the actually freq of your crystal, then factor this into the timer errors. And I am not sure how to do this to the accuracy needed to find the problem.

Intriguing problem,
Steve

[SelfishJosePino]

No, I didn't mention the Roman Black's web page by accident.

I good to know there is people not mean and selfish like JosePino. Anyway, I found quite interesting this forum.

Regards,
Jose Pino
www.josepino.com

Hi Darrel,
Some where Josepino had mentioned on his site that he had used Roman Black's one_sec.asm routine in his clocks (maybe he mentioned this by accident).
I tried making a similar program in PBP but had no success, till now.
Finally i got the progam running. its the exactly same one_sec.asm routine running with instant interrupts, and guess what,... it worked, and really accurately...
Its even more accurate than the Elapsed Timer...
I'll post the code so that it may be useful for someone...
(I'm not as mean and selfish as Josepino...
and thanks a lot for the instant interrupts program...
Chiao...

[shahidali55]

......................

[shahidali55]

Hello Jose Pino,
I found your LED and LCD clock projects very interesting...
Why dont you put your source codes online??? Its not like everyone is looking to make money by selling your codes or something...
Most of them, like me, just want to learn more in this wonderful world of microcontrollers!!!

[SelfishJosePino]

About one year and half ago, I was so mad and upset when I found some of my projects were used for commercial applications on Europe, specifically on Germany. After that, I decided not to post source codes and protect it with copyrights and patents.

Later, I started to receive some hate mail (Specially from Spanish-speaking readers) accusing me that my projects are stealed from other web pages, so I started to post algorithms of my projects. (only some of them)

Now, I receive many e-mails from hungy-of-knowledge people over the world asking me for source codes. At this point, I'm thinking seriously to make the source code available to the public.

As you can see, Is really hard to make everybody happy. So, I guess the best thing to do is to make the source code available for everybody. It may take a while until I have some time available to find the source code and put it online.

Regards,

Jose Pino
www.josepino.com

Hello Jose Pino,
I found your LED and LCD clock projects very interesting...
Why dont you put your source codes online??? Its not like everyone is looking to make money by selling your codes or something...
Most of them, like me, just want to learn more in this wonderful world of microcontrollers!!!

[shahidali55]

Hello Josepino,

It'll be great if you put your souce codes online...
Thanks for considering my posts...