Instant Interrupts - Revisited

[Charles Linquis]

Darrel,

I finally had a chance to try DT_Ints-18, and it works (of course) as advertised. I can't thank you enough for working on this and finishing it just as I had a pressing need.

Keep up the good work!

Can I ask for HI2CREAD and HI2CWRITE next? Real FUNCTIONS?

[b1arrk5]

That was fast!

My errors are as follows,
Warning[230]c:\pbp\18f4550inc 20:_config has been deprecated for PIC18 devices. Use directive CONFIG. (this is listed five times, then,)
Error[128]c:\progra~1\Mecani~1\example2.asm 1150:missing arguement(s)
Error[113]c:\ "" 602: Symbol not previously defined (INTFLAGREG)
603: Symbol not previously defined (INTFLAGBIT)
218: " (INTFLAGREG)
218: " (INTFLAGBIT)
656: ERROR (INTERRUPT SOURCE (INTFLAGREG,INTFLAGBIT) NOT FOUND
713: ERRORINT_ENABLE - Priority State Not Found)

Thanks, I'm dying to try this out!

Jerry Gavin

[mister_e]

about the CONFIG warning error look at the FAQ
http://www.picbasic.co.uk/forum/showthread.php?t=543

Now be sure all files are in the same directory (source code, include and so on)

Still having problem? post your whole code here.

HTH

[mister_e]

Can I ask for HI2CREAD and HI2CWRITE next? Real FUNCTIONS?

what you mean by 'real function' ? unless using Macro and INCLUDE files and as far as i'm aware of, we can't add in the existing function list... i would be so much handy.

Darrel... Yet another Plug-In application

[b1arrk5]

When you have eliminated all possible problems, the only one left, no matter how improbable must be the solution, to paraphrase Sherlock Holmes. I noticed that two of the files that I downloaded were showing up as smaller than the file sizes listed on Darrel's site. I deleted them and downloaded again, and everything compiled perfectly the first time! Works Great! I had just received a few 18F4550s to play with so Darrel's timing was perfect.

Also, thanks to Steve for the note regarding the Config problem.

Thanks to all,

Jerry Gavin

[Darrel Taylor]

Jerry,

Great, I'm so glad you found it. Never would have figured that out from here.

Charles,

You're welcome,

I think the HI2C, and HI2CSLAVE should be pretty easy now with DT_INTS. As well as HSPI and HSPISLAVE, PSPSLAVE, SSPWM, Multi-SSPWM, PWPS, Multi-PWPS, etc. etc. etc.

However, in order to facilitate some of those types of commands, I think the next step is a universal FIFO (First In First Out) buffer structure. Already have it working, but it looks real ugly right now.

As for Functions, I think Steve's right. Until we can gain control over the compiler, or the IDE, or maybe create a Pre-compiler, Functions will remain on the PBP wish list.

DT

P.S. My "Timing" is still not perfect though, since I've been totally sidetracked from the Elapsed Timer/Oscillator accracy problem.
<br>

[Demon]

This is just so cool, this stuff is exactly what I needed to service USB without having to figure out how much to sprinkle within the code.

Can't wait to try this after dinner.

Robert

[Christopher4187]

Darrel,

You said "If you increase the frequency of the timer Overflows, either by reducing the prescaler, or by re-loading the timer on each interrupt, or both, you can control the duty cycle within the interrupt handler."

When I look at your program, I am completely lost. Can you tell me exactly what variable(s) I have to changed to get the LED blink faster or slower?

Thanks,

Chris

[Darrel Taylor]

Chris,

The prescaler can be changed with T1CON.
$31 = 1:8
$21 = 1:4
$11 = 1:2
$01 = 1:1

And the Timer is reloaded by putting values in TMR1H:TMR1L.

So first, decide what frequency you need, I'll go with 100hz.

Then, go to this thread...
Testing Forms [TimerCalc] Working I think?
http://www.picbasic.co.uk/forum/showthread.php?t=2031

Enter the OSC value you are using, say 20mhz.
I'll also go with 1:1 prescaler, enter that. (ok, it's already there)
Then enter 100 in the Freq field at the bottom.

Now you can see that it will take a total of 50,000 counts (ticks) to achieve 100hz.

Decide what resolution you want for the Duty-Cycle. ummm, 8-bit (256).

Now you just calculate the ON count from that with...
50000*DutyCycle/256 which is the same thing as...
50000*/DutyCycle in PBP
and the OFF count is 50000 - ONcount

Ok, so let's put that into the Blinky Light example

; Initialize your hardware first.


INCLUDE "DT_INTS-18.bas"     ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ' Include if using PBP interrupts


LED1       VAR PORTB.1
DutyCycle  VAR BYTE


TotalCount CON 50000
ONcount    VAR WORD
OFFcount   VAR WORD


ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler   TMR1_INT,  _ToggleLED1,   PBP,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor
ENDASM


T1CON = $00                ; Prescaler=1:1, TMR OFF
@ INT_ENABLE  TMR1_INT     ; enable Timer 1 interrupts


Main:
    FOR DutyCycle = 0 TO 255           ; Ramp up
        GOSUB  SetDutyCycle
        PAUSE  5
    NEXT DutyCycle


    FOR DutyCycle = 254 TO 1 STEP -1   ; Ramp down
        GOSUB  SetDutyCycle
        PAUSE  5
    NEXT DutyCycle
GOTO Main




SetDutyCycle:
    ONcount = TotalCount*/DutyCycle
    OFFcount = TotalCount - ONcount
    IF DutyCycle = 0 THEN
        T1CON.0 = 0    ; turn off timer
        LOW  LED1      ; idle LOW
    ELSE
        T1CON.0 = 1    ; timer on if DutyCycle > 0
    ENDIF 
RETURN


DISABLE DEBUG
'---[TMR1 - interrupt handler]------------------------------------------------
@Timer1=TMR1L             ; map timer registers to a word variable
Timer1 VAR WORD EXT


ToggleLED1:
    IF LED1 THEN
        LOW LED1
        T1CON.0 = 0         ; stop the timer
        Timer1  = OFFcount  ; Load OFF count
        T1CON.0 = 1         ; start timer
    ELSE
        HIGH LED1
        T1CON.0 = 0         ; stop the timer
        Timer1  = ONcount   ; Load ON count
        T1CON.0 = 1         ; start timer
    ENDIF
@ INT_RETURN
ENABLE DEBUG