How instant are Instant Interupts?

[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
<br>

[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

[jmgelba]

Why would A = 6?

Before the goto, A is set to 0, then I'm counting up. If A becomes less than or equal to 4 something happens. If A = 5 then something else happens.

[Dave]

jmgelba, Because "While" it is the loop A is being incremented until it equals 6 right?

Dave Purola,
N8NTA

[jmgelba]

I thought I was incrementing it until it reached 5? If its equal or less than 4 (>=4) is does something, if it is =5 than it does something else. After it has reached either of those conditions it shouldnt increment again.