Aborting a PAUSE

Lightfoot

I have a very simple program that turns an LED on and off. I want the program to immediately stop if a switch on RA.2 is pushed. If I do it this way (see below) it may take one second to exit the loop. I want the RA.2 input to even override a pause command.

plp_a = 0

DO WHILE RA.2 = 1

RA.0 = ~RA.0
pause 1000

LOOP

rb = %00111100

Thanks

Post Edited By Moderator (Bean (Hitt Consulting)) : 7/29/2007 10:03:59 PM GMT

JonnyMac

You could use an edge-triggered interrupt on one of the RB pins, but this might be a little easier:

DO WHILE AbortBtn = No
  PAUSE 50
  INC ledTmr
  IF ledTmr = 20 THEN
    Led = ~Led
    ledTmr = 0
  ENDIF
LOOP

This checks the abort button 20 times per second, instead of once per second as with your code.

Lightfoot

Here is the main program I wish to perform abortions in (see attached). Each DO..LOOP performs a unique function. Pushing the RA.1 button does not break you out of the loops. The LED flasher portion Johnny posted does work. The RA.1 button is supposed to toggle between each of the three functions. Are interrupts the best way in this situation?

DEVICE          SX28, OSC4MHZ, TURBO, STACKX, OPTIONX
FREQ            4_000_000
PROGRAM Start

Start:

plp_a = 0
tris_b = 0
tris_c = 0
ctr var byte
rnd var byte

DO
    RC = %00000001 'Light Normal Mode LED indicator.
    RB = 255 'Turn lights on.
    
    DO WHILE RA.1 = 1 'Normal Mode (Activates dimmer switch.)
        IF RB < 255 THEN
            RB = RB + ~RA.2
        ENDIF
        IF rb > 0 THEN
            RB = RB - ~RA.3
        ENDIF
        PAUSE 2
    LOOP

    RC = %00000010 'Light Fade Mode LED indicator.

    DO WHILE RA.1 = 1 'Fade Mode (Lights adjust to a random brightness.)
        RANDOM rnd 'Generate random number.
        IF rnd <= RB THEN
            FOR ctr = RB TO rnd STEP -1
                DEC RB
                PAUSE 2
            NEXT
        ELSE
            FOR ctr = RB TO rnd
                INC RB
                PAUSE 2
            NEXT
        ENDIF                
    LOOP

    RB = 0
    RC = %00000100 'Light Blink Mode LED indicator. 

    DO WHILE RA.1 = 1 'Blink Mode (Lights turn on and off.)
        rb = ~rb
        pause 1000            
    LOOP 

LOOP

Connected to the RB port is another SX that dies the PWM command.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

Capdiamont

maybe another way to do it, is to have the main loop check the buttons, then gosub to your loops?

NOTE this isn't actual code

main:
if btn_a = 1 then mode = mode+1
if btn_b = 1 then goto THEEND
if mode => maxmode then mode=0

if mode = 0 gosub loopa
if mode = 1 gosub loopb
if mode = 2 gosub loopc
goto main

loopa:
turn output on
return

loopb:
if delaytemp = maxdelay then toggle output
if delaytemp = maxdelay then delaytemp = 0
delaytemp = delaytemp + 1
return

etc

OzStamp

Hi

If your just flashing a led why not
a pushbutton· +· resistor + flashing led all in series

············································ led that flashes by itself..
··············································|\
·+

---

·PushB·

---

[noparse][[/noparse]·resistor]

---

| ||----· -
············································· |/

Or a 555 timer astable with a reset button wired to pin 4

Ronald Nollet