DT Instant Interrupts

[krohtech]

Oh, sorry I forgou to mention I am using an 18F PIC. Can I use the timer template -14?

[skimask]

Oh, sorry I forgou to mention I am using an 18F PIC. Can I use the timer template -14?

You're talking about one of my favorite 'staples' whenever I build something...I call it a 'heartbeat'...
I have an LED connected to a specific pin...
I set up Timer 0 to run at a decent rate according to my main clock speed...i.e. once per second-ish, 4 times per second-ish, doesn't really matter, as long as I can see it blink.
Then every Timer 0 overflow, I increment a byte variable, last I set the LED to follow a certain bit of that variable.
So, say I use 'temp' as my variable.
myint:
temp = temp + 1
led = temp.0 'led will flash on/off every other time thru loop
resume

If the LED flashes too fast, I use temp.1, still too fast, maybe temp.2.
Or, conversely, if I use temp.4, and that flash is too slow, I'll use temp.3, or temp.2, whatever...until I find a flash rate that works for me.

DT's Fast interrupts and SSPWM code are great pieces of code...but I think they're big time overkill for what you want...

An example cut from one of my last programs:

'CONFIG statements semi-permanently set in PBP 18F4620 .INC file
resetplaceholder:	'18f4620 code
DEFINE OSC 10
DEFINE NO_CLRWDT 1	'no extra clear watchdog timer instructions
DISABLE
CLEAR
led1 var porta.5
heartbeat var byte
startupholder:
goto skipsubs	'skip over all the commonly used subroutines
ON INTERRUPT GOTO INTHANDLER
DISABLE
INTHANDLER:	if intcon.2 = 1 then			'timer 0 overflow interrupt handler
			intcon.2 = 0
                       heartbeat = heartbeat + 1
                        led1 = heartbeat.0		'led flash about every ~1.6 seconds
' change heartbeat.0 to heartbeat.X where x = 0 - 7 to change heart beat flash rate
INTFINISH:
RESUME
DISABLE
'end of commonly used subroutines, skipsubs block for setting up registers, lcd, whatever else...
skipsubs:
	t0con = $84
        intcon = $e0
        cmcon = 7
        pie2 = $80
        trisa = 0
        porta = 0
        led1 = 0
        output led1
' change prescale value in $84 to change flash rate
ENABLE
mainloop:
' do something useless or useful here
goto mainloop
END

IF you're not using a '4620, then you'll have to figure out which registers need which values as far as interrupt and timer registers go.
I chose porta.5 because it was available. Change that to what you need also.

[Darrel Taylor]

I need a system LED that just blinks at a constant speed like 4 times a second. to show that the pic is working.

  ... and ...

Oh, sorry I forgou to mention I am using an 18F PIC. ...

I'm thinking just the Blinky example is all you need.

DT_INTS-18 (Blinky Light)
http://darreltaylor.com/DT_INTS-18/blinky.html

Or, even better ...

DT_INTS-18 (Assembly Language Interrupts)
http://darreltaylor.com/DT_INTS-18/asm_ints.html

Same Blinky LED, without the Basic Language Interrupt overhead.

And no running Colon's
<br>

[krohtech]

DT_INTS-18 (Assembly Language Interrupts)
http://darreltaylor.com/DT_INTS-18/asm_ints.html

Yes, this is the code I am using but I can't get it working in the same program as the multi SPWM. I am useing multi SPWM for my 8 pwm dimmers.

Also I have played with the prescaler to slow down the blink rate but have had no sucess. is there a formula for this like in the -14 version?

I will also make an attempt to digest Skymask's timer 0 overflow interrupt handler in the morning.

Thanks Darrel and Skymask. You are both very helpful.

[Darrel Taylor]

The original SPWM will not work with Instant Interrupts.
They both want complete control of the interrupts. (can't happen)

However, SPWM_INT will work with Instant Interrupts.
And yes, the version shown in the -14 section will work on the 18F's too.

DT_INTS-14 (SPWM_INT - Multiple Software PWM)
http://darreltaylor.com/DT_INTS-14/SPWM.html

SPWM_INT uses Timer1, so if you also want a Blinky light, you'll need to use a different Timer. (0, 2 or 3)

And if you want to use either of the SPWM versions, then you can't use skimask's code.
They are not compatible with ON INTERRUPT.
<br>

[skimask]

And if you want to use either of the SPWM versions, then you can't use skimask's code.
They are not compatible with ON INTERRUPT.
<br>

And if you want my opinion (nobody really does, but that's beside the point), you'd do real good to learn how to use DT's Instant Interrupt's instead of relying on PBP's On Interrupt.
It's not only good coding with good applications, you just plain learn a lot in the process...and then you spend more money and more time on PICs and PBP and less time on...well, wait a minute...gotta eat sometime...right?

[krohtech]

I have SPWM_INT working really well. I am doing 16 ch of PWM on a pic 18F2410 32 MHz. The pwm is running at 100Hz 8 bit resolution.

SPWM_INT uses Timer1, so if you also want a Blinky light, you'll need to use a different Timer. (0, 2 or 3)
<br>

Here is where I am having trouble. I tried to add a blinky from the DT_INTS-18 example and change it to timer0 with no success. Darrel, can you point me in the correct direction?

[krohtech]

here is my current code, changed to 101 PWM resolution to reduce overhead

'-----------------------------SPWM INT-----------------------------
CLEAR

INCLUDE "DT_INTS-18.bas"            ; Base Interrupt System
INCLUDE "SPWM_INT.bas"              ; Software PWM module
INCLUDE "ReEnterPBP-18.bas"    ; Include if using PBP interrupts

LED2 VAR PORTA.5

DEFINE SPWM_FREQ  100                ; SPWM Frequency
DEFINE SPWM_RES   101               ; SPWM Resolution

DutyVars   VAR BYTE[16]              ; DutyCycle Variables
  DutyVar1 VAR DutyVars[0]          ; group them in an array for easy access
  DutyVar2 VAR DutyVars[1]          ; with FOR loops etc.
  DutyVar3 VAR DutyVars[2]
  DutyVar4 VAR DutyVars[3]
  DutyVar5 VAR DutyVars[4]
  DutyVar6 VAR DutyVars[5]
  DutyVar7 VAR DutyVars[6]
  DutyVar8 VAR DutyVars[7]
  DutyVar9 VAR DutyVars[8]          
  DutyVar10 VAR DutyVars[9]         
  DutyVar11 VAR DutyVars[10]
  DutyVar12 VAR DutyVars[11]
  DutyVar13 VAR DutyVars[12]
  DutyVar14 VAR DutyVars[13]
  DutyVar15 VAR DutyVars[14]
  DutyVar16 VAR DutyVars[15]
  
ASM
SPWM_LIST  macro                    ; Define Pin's to use for SPWM
     SPWM_PIN  PORTB, 0, _DutyVar1  ; and the associated DutyCycle variables
     SPWM_PIN  PORTB, 1, _DutyVar2  ; Notice the underscore before variables
     SPWM_PIN  PORTB, 2, _DutyVar3
     SPWM_PIN  PORTB, 3, _DutyVar4
     SPWM_PIN  PORTB, 4, _DutyVar5
     SPWM_PIN  PORTB, 5, _DutyVar6
     SPWM_PIN  PORTB, 6, _DutyVar7
     SPWM_PIN  PORTB, 7, _DutyVar8
     SPWM_PIN  PORTC, 0, _DutyVar9 
     SPWM_PIN  PORTC, 1, _DutyVar10 
     SPWM_PIN  PORTC, 2, _DutyVar11
     SPWM_PIN  PORTC, 3, _DutyVar12
     SPWM_PIN  PORTC, 4, _DutyVar13
     SPWM_PIN  PORTC, 5, _DutyVar14
     SPWM_PIN  PORTC, 6, _DutyVar15
     SPWM_PIN  PORTC, 7, _DutyVar16 
     endm
  SPWM_INIT  SPWM_LIST              ; Initialize the Pins
ENDASM

ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler   TMR1_INT,  SPWMhandler,  ASM,  yes
        INT_Handler   TMR0_INT,  _ToggleLED2,  PBP,  yes

    endm
    INT_CREATE                      ; Creates the interrupt processor
ENDASM

T0CON = %10010010             ; T0 = 16-bit, Prescaler 8
@ INT_ENABLE  TMR1_INT        ; enable Timer 1 interrupts
@ INT_ENABLE  TMR0_INT        ; enable Timer 0 interrupts


'-----------------------------Main Program-----------------------------
Main:

[Darrel Taylor]

I think the Cut&Paste didn't catch everything.

Can you post the Main: and Handler parts?
Thanks.