Interupt for RB1 & RB2

[itmsoil]

Help is needed guys.
i am trying to implement this program below but using either
RB1 or RB2 as RB0 on my pic is already being used. i am using a
pic18f452
Could another help out .


' On Interrupt - Interrupts in BASIC Using 18f452
' Turn LED on. Interrupt on PORTB.0 (INTE) turns LED off.
' Program waits .5 seconds and turns LED back on.

led var PORTB.7

INTCON2.7 = 0 ' Enable PORTB pullups
INTCON2.6 = 0 'interupt on falling edge

On Interrupt Goto myint ' Define interrupt handler
INTCON = $90 ' Enable INTE interrupt

loop: High led ' Turn LED on
Goto loop ' Do it forever


' Interrupt handler
Disable ' No interrupts past this point
myint: Low led ' If we get here, turn LED off
Pause 500 ' Wait .5 seconds
INTCON.1 = 0 ' Clear interrupt flag
Resume ' Return to main program
Enable



Itm

[Dave]

You need to look at your data sheet for the 18F452 page 76 & 77 as they tell you what bits to be set for RB1 & RB2. INTCON2 bit 4 & 5 set the edge to trigger the interrupt. INTCON3 bits 6 & 7 set the interrupt priority, INTCON3 bits 3 & 4 set the enable mask and INTCON3 bits 0 & 1 are the interrupt flags set for the ports RB1 & RB2. It's all in the document.....

[itmsoil]

Dave Thank for the pointer
i have manage to get just RB0 and RB2 working but i do get strange results for RB1
when i press the button connected to Rb1, the the message Rb0 pressed displayed before displaying Rb1 pressed.
Could someone please help me with this


DEFINE LOADER_USED 1 ' uses a bootloader
INCLUDE "Modedefs.Bas"

' ** Setup Crystal Frequency in mHz **

DEFINE OSC 20 ' Set Xtal Frequency

DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTD
DEFINE LCD_RSBIT 1
DEFINE LCD_EREG PORTD
DEFINE LCD_EBIT 0
DEFINE LCD_RWREG PORTD ' PORTD for R/w bit
DEFINE LCD_RWBIT 2 ' PORTD-1 for LCD's R/W line
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000' Command Delay (uS)
DEFINE LCD_DATAUS 50 ' Data Delay (uS)



I CON 254 ' Control Byte
Clr CON 1 ' Clear the display
Line1 CON 128 ' Point to beginning of line 1
Line2 CON 192 ' Point to beginning of line 2



' ** Define the bits within the ADCON1 register **

index VAR BYTE
R0 VAR BYTE
R1 VAR BYTE
R2 VAR BYTE
TRISA=%00111111
TRISB=%00100111
TRISC=%10100110
TRISD=%00001000
TRISE.0=1
TRISE.1=1
TRISE.2=1


INTCON2.7=0 'Enable portB pullups
INTCON2.6=0 '%Interupt on falling edge



Main:



Pause 1000 ' delay for lcd

Loop:
'==== ================================================== ========================
LCDOut I,Clr
LCDOut I,Line1,"Power on"

For index =1 TO 500
Pause 1
Next index

ON INTERRUPT GoTo myint1 ' Define interrupt handler
INTCON=%10010000 ' Enable RB0 interupt

'The RB0 interupts works ok but RB1 & RB2 don't
'Dummy code
'kkkkkkkkkkkkkkkkkkk

ON INTERRUPT GoTo myint2 ' Define interrupt handler
INTCON2.4=0: INTCON2.5=0 ' Enable RB2 interupt
INTCON3.7=1:INTCON3.6=1
INTCON3.4=0:INTCON3.3=1

ON INTERRUPT GoTo myint3 ' Define interrupt handler

INTCON2.4=0: INTCON2.5=0 ' Enable RB2 interupt
INTCON3.7=1:INTCON3.6=1
INTCON3.4=1:INTCON3.3=0


GoTo Loop

End


' RB0 Interrupt handler
' ===========================

myint1:
Disable ' No interrupts past this point
LCDOut I,Clr
LCDOut I,Line1,"RB0 Pressed"
For R0 = 1 TO 500 ' allow user to see
Pause 1
Next
INTCON.1 = 0 ' Clear interrupt flag
Resume ' Return to main program
Enable


' RB1 Interrupt handler
' ===========================
myint2:
Disable ' No interrupts past this point
LCDOut I,Clr
LCDOut I,Line1,"RB1 Pressed"
For R1 = 1 TO 500 ' allow user to see
Pause 1
Next

INTCON3.0 = 0 ' Clear interrupt flag
INTCON3.1 = 0
Resume ' Return to main program
Enable


' RB2 Interrupt handler
' ===========================
myint3:
Disable ' No interrupts past this point

LCDOut I,Clr
LCDOut I,Line1,"RB2 Pressed"
For R2 = 1 TO 500 ' allow user to see
Pause 1
Next
INTCON3.0 = 0
INTCON3.1 = 0 ' Clear interrupt flag
Resume ' Return to main program
Enable




Itm

[Dave]

Well you almost have it right. There is only 1 interrupt vector or in other words there can only be 1 interrupt routine. Therefore after entering the interrupt routine you must check each interrupt flag to see which interrupt occured and service that interrupt. After this you must clear the approprate interrupt flag then return.

Dave Purola,