How instant are Instant Interupts?

[jmgelba]

DT, that wont work. The output has to reflect the input up to a maximum on time then the output has to be turned off regardless of input state.

Delay = 1000

Wait4Pulse: 
    IF !PORTA.0 THEN Wait4Pulse     ; Wait for incoming pulse
    PORTA.1 = 1                     ; Start Output pulse
    PAUSEUS Delay                   ;   pause for pulse width *** this will keep the output on for 1000uS, not for the duration of PORTA.0 = 1
    PORTA.1 = 0                     ; End of Output pulse

Wait4PulseEnd:                      ; Make sure input pulse is finished
    IF PORTA.0 THEN Wait4PulseEnd

GOTO Wait4Pulse

[Darrel Taylor]

DT, that wont work. The output has to reflect the input up to a maximum on time then the output has to be turned off regardless of input state.

Now you tell me!
That wasn't part of the plan.

The schematics above don't apply then. Nor does the example.
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[jmgelba]

2 different projects/ideas.

This last one has nothing to do with the first one. Its a pulse follower with a protective cut off.

[jmgelba]

I am still very interested in the first one and looking forward to taking a look at the code.

The second one was me trying to learn timers and how to manipulate them.

[Darrel Taylor]

And now for something Completely Different!

Main brains only got 1 track left.
Ya gotta tell me when to switch to track B ...

OK, back to the first problem.
I've got this code for the last schematic.
It hasn't even seen an electron yet, but I think it's close, although it's guaranteed to change.

I'm trying to make a breadboard for it.
But it's going slower than anticipated. (blame Half-Life).

Here's what I got ...
http://www.pbpgroup.com/files/ZeroDelay1.htm
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[jmgelba]

Interesting peice of code - over my head for the moment.

Going back to the pulse following example, here is a piece of code I came up with at about 4am this morning.

OSCCON = $70 'set internal resonator to 8mhz
DEFINE OSC 8
ADCON0 = %00000001
ADCON1 = %01111100
ADCON2 = %10111110

PORTB = %00000111 
TRISA = %11111111
TRISB = %11110000

loop:
IF PORTA.5 = 0 THEN flash
GOTO loop

FLASH:
PORTB = %00001100          'turns on fets
A = 0                               'resets count to 0

while A <= 5                      'follow status of i/p turn off fets if i/p goes away
PORTB = %00001100           
A = A + 1
IF (PORTA.5 = 1) THen
PORTB = %00000111
WEND
if (A <=4) THEN
GOTO loop
if (A = 5) then                    'if A=5 fets are still on
pauseus 1500                     'set max time for fets to be on
PORTB = %00000111           'turn off fets
IF (PORTA.5 = 0) THEN        'if i/p is still on, wait 2ms then repeat loop
pause 2 
return

[Dave]

jmgelba , These lines will never execute because of the value of "A" before hand.

if (A <=4) THEN <<<<<<<<<<<<<<<<<<<<<<<<< here A = 6
GOTO loop
if (A = 5) then 'if A=5 fets are still on <<<<<<<<<<<<<<<< here A = 6
pauseus 1500 'set max time for fets to be on
PORTB = %00000111 'turn off fets

Also wheres the ENDIF's?

Dave Purola,
N8NTA