I am stumped!!!

[tazntex]

keypad ohms out good, brand new actually, but as I mentioned before PortB.1-3 are my rows and 4-7 are my columns with the above code, pressing a button on the keypad does not pull any pin low.

[tazntex]

I changed TRISB = %11111110 to TRISB = %11110000 now pressing keypad the selected PORTB 4-7 pulls low to 2.2VDC, by the way PORTB.0 is connect first in series with a 330 ohm resistor, then to the four 1N4148's. I thought limiting the current to 15mA would be easier on the internal pull-ups.

[tazntex]

Thanks for the drawing, that is how this is connected, yes I am aware of "scanning the keypads" Bruce has been a great help, but I am just narrowing it down to pressing on button, pins 1-3 low, and pin 0 high just to see how interrupt's work. I am looking to use the interrupt to sleep all the time, detect when key is pressed, wake up, set PORTB.0, and 4-7 as inputs, bits 1-3 as out, pause about 50, then began scanning keypad something like this:

recycle:
@ Sleep
@ NOP
@ NOP
goto recycle

' my Interrupt handler
search:
PORTB = 0
TRISB = $f1
PAUSEUS 10
keypadscan:
FOR row = 1 TO 3
PORTB = 0
TRISB = (DCD row) ^ $fe
col = PORTB >> 4
IF col != $f THEN keypressed
NEXT row
GOTO recycle

Haven't got all this worked out yet, but thats another day

[tazntex]

I'm just stumped with the original code above why am I already in the interrupt when I power up, just to confirm that I changed the INT handler to:
'---[INT - interrupt handler]---------------------------------------------------
ToggleLED1:
TOGGLE LED
pause 50
@ INT_RETURN

and sure enough the led is flashing...

By the way, what program are you using to upload your schematic?

[tazntex]

Hmmm, came back here today to focus on the post here from Bruce but it seems to have vanished, or am I losing my mind? Maybe its both

Anyhow, it was mentioned that so to speak that I should take a snapshot of PortB, I am so lost. If on power up PortB.0 is high and pullups are enabled, on the rest of the pins: TRISB = %11111110 PortB = %00000001 then with my meter focusing on pins 4-7 shows 5VDC or logic HIGH, should I do this:

WHILE (portb >> 4) != 15
pause 20
wend
INTCON.0 = 0
return

or substitute 15 for a 0?

Seems it would be 15 but with that I apparently staying in my interrupt routine.

I've been experimenting with ON INTERRUPT and Darryl Taylor's Instant Interrupts:

DEFINE OSC 4
CMCON=%00000111
VRCON = 0
PAUSEus 10
TRISA = %00000110
TRISB = %11111110
PORTA = %00000000
PORTB = %00000001
OPTION_REG.7 = 0
OPTION_REG.6 = 0
INTCON = %00001000

led var portA.3
INCLUDE "DT_INTS-14.bas" ; Base Interrupt System
INCLUDE "ReEnterPBP.bas" ; Include if using PBP interrupts
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler RBC_INT, _check, PBP, yes
endm
INT_CREATE

ENDASM
@ INT_ENABLE RBC_INT
PAUSE 50

cycle:
gosub readportb
HIGH led
pause 100
LOW led
pause 100
@ Sleep
@ Nop
@ Nop
goto cycle

readportb:
WHILE (portb >> 4) != 15
PAUSE 20
WEND
INTCON.0 = 0
return


check:
PAUSE 250
WHILE (portb >> 4) != 15
PAUSE 20
WEND
@ INT_RETURN


Any Suggestion, preferably in Crayola so its clear?

Thanks

[Bruce]

Try this;

DEFINE OSC 4
CMCON=%00000111
VRCON = 0 
PAUSEus 10 
TRISA = %00000110
TRISB = %11110000   ' using upper 4-bits for interrupt
PORTA = %00000000 
PORTB = %00000001
OPTION_REG.7 = 0 
OPTION_REG.6 = 0
 
led var portA.3
 
INCLUDE "DT_INTS-14.bas" ; Base Interrupt System
INCLUDE "ReEnterPBP.bas" ; Include if using PBP interrupts
 
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
    INT_Handler RBC_INT, _check, PBP, yes
    endm
    INT_CREATE 
ENDASM
 
@ INT_ENABLE RBC_INT 
 
cycle:
    HIGH led
    pause 100
    LOW led
    pause 100
    @ Sleep
    goto cycle
 
check: 
    WHILE (portb >> 4) != 15
      PAUSE 10
    WEND 
    @ INT_RETURN

The purpose of WHILE (portb >> 4) != 15 is to wait until a button that generated the interrupt is released. It also reads the port, which is required before DT_INTs can clear the interrupt flag.

To clear the interrupt-on-change flag bit you first have to read the port, then clear the flag. If you read the port while a button is still pressed, then clear the flag, another interrupt will be generated once the button is released.

[tazntex]

Thanks a million Bruce, I will try that now.

P.S. I about fell on the floor laughing when I refreshed the page and say the crayon