"Extending" timer1

[chips123]

Aratti,
I think I understand the concept, but where would I put the variable increment in my code example? In the main loop, or something in the interrupt routine? That is basically what I was doing with the y=y+545. There I was only able to keep track of one overflow. In my interrupt, I am actually working with the previous timer value, not the current running timer value.

Thanks for the reminder on the EEPROM thing.
Scott

[Jumper]

If you look at the microchip EE-prom lifetime test they have compared different brands.. some better and some worse. I bet there is some advertising involved in the numbers but some brands only guarantee 100k write cycles. 100k or a million makes a difference.

[aratti]

but where would I put the variable increment in my code example?

chips123

Naturally in your interupt routine. Let assume you have a variable Tmr1Z (declared as Word) and you increment TMR1Z by 1 at each overflow then TMR1L & TMR1H and TMR1Z will give you a 32 bits count from which you could pullout a lot of information.

Also y = y + 525 could be used but since y will overflow itself after 124 timer1 overflow is not very helpfull.

100k or a million makes a difference.

Jumper

One is ten times the other! 100K makes life even more difficult.

For pic 16F676 this is what datasheet report:

- 100,000 write FLASH endurance
- 1,000,000 write EEPROM endurance
- FLASH/Data EEPROM Retention: > 40 years

Al.

[chips123]

I thought about this some more and thought that I came to the conclusion that I should do it in the main loop. When I used the y=y+525 in the interrupt routine, it only worked for the first timer overflow. Since the interrupt only cycles through once and the timer continues to run even if an interrupt has not happened, I figured I would need to keep checking for the overflow in my main loop. Let me know what you think of this. I wil need to try it tonight. Thanks.

[aratti]

I had the impression it was an INTERRUPT ON OVERFLOW routine.

Why don't you use Darrel Taylor instant interrupt, it is easy to use and works very well indeed!

Visit Darrel site @ http://darreltaylor.com/DT_INTS-14/intro.html

Al.

[chips123]

I put the new overflow checking inside the little delay loop (delay value was shortened) of the main loop and the results seem right. I need to verify w/ scope. I have been meaning to check out the Darrel Taylor interrupt greatness. Until the next stumbling block. Thanks,Scott