TMR2 not working..

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- 1st August 2007, 20:39
sirvo

TMR2 not working..

Hello..

I'm trying to make 16f88 'interrupt' every 500ms. TMR0/1 are busy. So, I've set TMR2 to interrupt every 1ms and then count var TMR2_clock till 500. But, it is interrupting every 3ms or something... Would you help me?

Code:

'------- initial -------------------- TMR2_clock VAR WORD OPTION_REG = %00000000 INTCON = %11000000 ' enable interrupts TRISB = %00000000 ' portb all output TRISA = %00111111 ' some analog inputs ANSEL = %00001111 ' some analog inputs CMCON = %00000111 ' turn of comparators ADCON1 = %10000000' right justified T2CON = %00000011 ' TMR2 prescale 1:16 '--------------------------------------------------- TMR2_clock = 0 Lcdout $FE,1 ' clear screen PR2 = 194 ' load tmr2 PR2 to reset every 1ms PIE1.1 = 1 ' enable TMR2 interrupt PIR1.1 = 0 ' disabled interrupt flag - TMR2 T2CON.2 = 1 ' turn TMR2 on ON INTERRUPT GOTO tick MAIN: ' do nothing GOTO MAIN DISABLE tick: PR2 = 194 'reload PR2 TMR2_clock = TMR2_clock + 1 Lcdout $FE,$A0, DEC TMR2_clock IF TMR2_clock = 500 THEN TMR2_clock = 0 ' Set some flag.. ENDIF PIR1.1 = 0 resume ENABLE

Thanks..!

Sylvio
- 1st August 2007, 21:03
Darrel Taylor

The default LCD_COMMANDUS is 2000 us. (2 ms)
So moving the cursor to a specific location within the ISR makes it wait that much longer before it Resume's.

Add in the 50us for each character displayed, and the 1ms for the interrupt itself, and you get "3ms or something...".

HTH,
- 1st August 2007, 21:15
sirvo

Right.. i just put the LCDOUT command to compare the count with my hand watch. So, the routine is correct.. thanks Darrel.

Sylvio
- 1st August 2007, 21:38
Darrel Taylor

Quote:

... So, the routine is correct..

Good to go ...
One thing to note ...
You don't need to reload PR2 each time. It doesn't change.
- 1st August 2007, 21:41
sirvo

0.o I've read that a thousand times and still reloaded..Thanks again..

Sylvio
- 1st August 2007, 22:52
sirvo

tmr2 is running crazy yet

HI Again... I have tried again taking the LCDOUT command out of interrupt routine and putting inside the MAIN sub. NOthing! It is running crazy and I've also tried setting postscaler 1:16 or/and prescaler 1:16 and still nothing. Does the code look really correct? What I want is to set any flag every 500ms using TMR2... A little help please?

Thanks again.. Sylvio, :)

Code:

'------- initial -------------------- TMR2_clock VAR WORD OPTION_REG = %00000000 INTCON = %11000000 ' enable interrupts TRISB = %00000000 ' portb all output TRISA = %00111111 ' some analog inputs ANSEL = %00001111 ' some analog inputs CMCON = %00000111 ' turn of comparators ADCON1 = %10000000' right justified T2CON = %00000011 ' TMR2 prescale 1:16 --> TESTED WITH POST and PRESCALER (1:16) '--------------------------------------------------- TMR2_clock = 0 Lcdout $FE,1 ' clear screen PR2 = 194 ' load tmr2 PR2 to reset every 1ms PIE1.1 = 1 ' enable TMR2 interrupt PIR1.1 = 0 ' disabled interrupt flag - TMR2 T2CON.2 = 1 ' turn TMR2 on ON INTERRUPT GOTO tick MAIN: Lcdout $FE,$A0, DEC TMR2_clock ---> CHANGED GOTO MAIN DISABLE tick: TMR2_clock = TMR2_clock + 1 IF TMR2_clock = 500 THEN TMR2_clock = 0 ' Set some flag.. ENDIF PIR1.1 = 0 resume ENABLE
- 1st August 2007, 23:03
Darrel Taylor

You've just moved the time to write to the LCD to a different place.

When using ON INTERRUPT, it can't handle an interrupt until the current statement has finshed executing.

If you want to have a 1ms interrupt, then nothing else in the program can take more than 1ms to execute, and really should be much less than that.

If you were using ASM interrupts, then it could interrupt the LCDOUT statement, so there wouldn't be a conflict.

Or you could use Instant Interrupts to do the same thing with Basic language interrupts without the ON INTERRUPT.
- 2nd August 2007, 03:27
sirvo

Instant Interrupts...

OK. Let's try the instant interrupts. I have just added the II codes and it looks like this:

Code:

@ ERRORLEVEL -306 ; turn off crossing page boundary message @ __CONFIG _CONFIG1, _CP_OFF & _DEBUG_OFF & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_OFF & _PWRTE_ON & _WDT_OFF & _XT_OSC INCLUDE "DT_INTS-14.bas" ' Base Interrupt System INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts ASM ;T0IF = TMR0IF ;T0IE = TMR0IE INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler TMR2_INT, _tick, PBP, yes endm INT_CREATE ; Creates the interrupt processor ENDASM @ INT_ENABLE TMR2_INT ; Enable Timer 1 Interrupts '------- initial -------------------- TMR2_clock VAR WORD OPTION_REG = %00000000 ' INTCON = %11000000 ' enable interrupts ->NOW COMMENTED TRISB = %00000000 ' portb all output TRISA = %00111111 ' some analog inputs ANSEL = %00001111 ' some analog inputs CMCON = %00000111 ' turn of comparators ADCON1 = %10000000' right justified T2CON = %00000011 ' TMR2 prescale 1:16 --> TESTED WITH POST and PRESCALER (1:16) '--------------------------------------------------- TMR2_clock = 0 Lcdout $FE,1 ' clear screen PR2 = 194 ' load tmr2 PR2 to reset every 1ms 'PIE1.1 = 1 ' enable TMR2 interrupt -> NOW COMMENTED 'PIR1.1 = 0 ' disabled interrupt flag - TMR2 -> NOW COMMENTED T2CON.2 = 1 ' turn TMR2 on 'ON INTERRUPT GOTO tick -> -> NOW COMMENTED MAIN: Lcdout $FE,$A0, DEC TMR2_clock ---> CHANGED GOTO MAIN tick: TMR2_clock = TMR2_clock + 1 IF TMR2_clock = 500 THEN TMR2_clock = 0 ' Set some flag.. ENDIF @ INT_RETURN

Well.. the LCD gets cleared. No text at all..

What's wrong?

Thank you.

Sylvio
- 2nd August 2007, 03:59
Darrel Taylor

What pins are the LCD hooked up to?

Without the DEFINES, the LCD defaults to PORTA 0-3 for the data, but those pins are configured for analog.

You had the same settings before and said it was working so I assumed there were defines that you didn't show. But now it looks like there aren't any.
- 2nd August 2007, 04:10
sirvo

The lcd defines are the same. It's hooked up on PORTB. I did not change defines.
I've added the two .bas instant interrupt files, added the asm code and changed all the interrupt statement to the instant interrupt. I have no ideia where the problem is located to.. i'm still trying to do so..

I still have some doubts about instant interrupts and timer using, like reloading and also configuring Option_reg or intcon...

did not you really read anything wrong in the code posted?

Thanks for the attention Darrel.
- 2nd August 2007, 04:35
Darrel Taylor

Quote:

Originally Posted by sirvo

The lcd defines are the same. It's hooked up on PORTB. I did not change defines.

That's the part I don't get. There are no DEFINEs for the LCD. So it won't work on PORTB. Unless you just didn't include them in the post.

Quote:

did not you really read anything wrong in the code posted?

No I don't.
I've run the program here, with a few changes. Using a 16F877.

I did change the $A0 in the LCDOUT statement.
Changed it to $80. All works fine.
- 2nd August 2007, 04:40
sirvo

Quote:

Originally Posted by Darrel Taylor

That's the part I don't get. There are no DEFINEs for the LCD. So it won't work on PORTB. Unless you just didn't include them in the post.

I'm sorry. I did not post them here, but they are correct.
I'll try again later...I'm sleepy now..

Thank you very much..
- 2nd August 2007, 15:24
sirvo

As I have said, the LCD gets a cleared screen. IN order to test the ASM routine of instant interrupt, I have added 2 LCDOUT commands. The first before the ASM routine and the Second after the ASM ROUTINE.

Code:

' LCD defines on portB ' All registers set ' just like the code posted before Pause 1000 LCDOUT $FE, $80, "TEST 1" ASM ;T0IF = TMR0IF ;T0IE = TMR0IE INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler TMR2_INT, _tick, PBP, yes endm INT_CREATE ; Creates the interrupt processor ENDASM @ INT_ENABLE TMR2_INT ; Enable Timer 1 Interrupts LCDOUT $FE, $80, "TEST 2" 'and the rest of the code goes i here..

Well.. Now the LCD displays only "TEST 1".. it seems that the pointer is stuck in the ASM lines... Anything to say?

Thanks!
- 2nd August 2007, 17:41
sirvo

Darrel.... are you there?

I 'discovered' that if I set PR2 to any number it DO NOT interrupt...
If I let PR2 'unset' it interrupts normal...

In this case I am going to use it in this way, letting TMR2 count until 0FFh. Anyway, do you know what is hapening?

Thanks...
- 2nd August 2007, 17:46
Darrel Taylor

Working on it.

Building a 16F88 breadboard now. (Last couple hours)

I'll get back to you.
- 2nd August 2007, 18:54
Darrel Taylor

1 Attachment(s)

Got it working, and I only found one problem.

The 194 would be for timer 0. Where it counts from that number until it overflows at 256, which takes 62 counts.

Timer 2 works a little different.
It counts from 0 up to the number in PR2, then resets to 0 again.
So 62 is the number for PR2 @ ~1ms. It's actually 62.5, so we may need to drop the prescaler to 4 and use 250 for PR2 if you want more accuracy.

I do not see any problems with the interrupt portions, and it all works fine here. Here's the breadboard I just put together.

<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1902&stc=1&d=118607629 9">

And here's the program I'm using ...

Code:

; http://www.picbasic.co.uk/forum/showthread.php?t=6818 @ ERRORLEVEL -306 ; turn off crossing page boundary message @ __CONFIG _CONFIG1, _CP_OFF & _DEBUG_OFF & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_OFF & _PWRTE_ON & _WDT_OFF & _XT_OSC DEFINE LCD_DREG PORTB ' LCD data port DEFINE LCD_DBIT 0 ' LCD data starting bit 0 or 4 DEFINE LCD_RSREG PORTB ' LCD register select port DEFINE LCD_RSBIT 4 ' LCD register select bit DEFINE LCD_EREG PORTB ' LCD enable port DEFINE LCD_EBIT 5 ' LCD enable bit PAUSE 500 : LCDOUT $FE,1 : PAUSE 250 ; Initialize LCD LED VAR PORTA.4 INCLUDE "DT_INTS-14.bas" ' Base Interrupt System INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts ASM ;T0IF = TMR0IF ;T0IE = TMR0IE INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler TMR2_INT, _tick, PBP, yes endm INT_CREATE ; Creates the interrupt processor ENDASM @ INT_ENABLE TMR2_INT ; Enable Timer 1 Interrupts '------- initial -------------------- TMR2_clock VAR WORD OPTION_REG = %00000000 TRISB = %00000000 ' portb all output TRISA = %00111111 ' some analog inputs ANSEL = %00001111 ' some analog inputs CMCON = %00000111 ' turn of comparators ADCON1 = %10000000' right justified T2CON = %00000011 ' TMR2 prescale 1:16 '--------------------------------------------------- TMR2_clock = 0 LCDOUT $FE,1 ' clear screen PR2 = 62 ' load tmr2 PR2 to reset every 1ms T2CON.2 = 1 ' turn TMR2 on MAIN: LCDOUT $FE,$80, DEC TMR2_clock," " ;---> CHANGED GOTO MAIN tick: TMR2_clock = TMR2_clock + 1 IF TMR2_clock = 500 THEN TMR2_clock = 0 TOGGLE LED ' Set some flag.. ENDIF @ INT_RETURN 

The LED flashes at almost 1 hz, and the numbers on the LCD are counting away.

I say "almost" due to the Timer 2 prescaler. For better accuracy, use ...

Code:

T2CON = %00000001 ' TMR2 prescale 1:4 PR2 = 250 ' load tmr2 PR2 to reset every 1ms
- 2nd August 2007, 20:31
sirvo

Hi.
Darrel, my native language isn´t english and because of that there are some words still not added in my english vocabulary but I am really amazed to see someone like you that helped me a lot and obtained nothing for it. Thank you very much for working on TMR2 stuffs and solving my problem.
- 2nd August 2007, 23:17
Darrel Taylor

You're welcome Sylvio.

I hope that means you have it working too.

Regards,