Problem with interrupts

[rjwheatonsr]

Forgot to mention: chip is 16F1938. I have a problem that I can't seem to solve. I have a program that reads some "remote" switches via one-wire. That portion of the program works just fine. I also flash turn signals depending on the state of the switches, and that works fine also. However, intermittently the scan of the one-wire circuit returns all "1"s, as if all of the switches were open. After trying various things, I determined that the interrupts were the problem, as well as the solution. Can anyone tell me why this is happening, and possibly suggest a solution?

Is it possible to temporarily disable the interrupts while I'm reading the one-wire bus?

@ ERRORLEVEL -306 ;Turns off page boundry error messages
#CONFIG
__config _CONFIG1, _FOSC_INTOSC & _WDTE_OFF & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOREN_OFF & _CLKOUTEN_OFF & _IESO_OFF & _FCMEN_OFF
__config _CONFIG2, _WRT_OFF & _PLLEN_OFF & _STVREN_OFF & _BORV_LO & _LVP_OFF & _VCAPEN_OFF
#ENDCONFIG
'
OSCCON = %01110000
DEFINE OSC 8
DEFINE HSER_BAUD 9600
define SHOWDIGITAL 1
'
INCLUDE "ALLDIGITAL.PBP"
INCLUDE "DT_INTS-14.BAS"
INCLUDE "ReEnterPBP.BAS"
'
'INITIALIZE PORTS
TRISA = %00001111
TRISB = %00000000
TRISC = %00000000
'
ONEWIRE VAR PORTC.0 'PIN 15
' '
ID VAR BYTE[8] ' Array storage variable for 64-bit ROM code '
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''PIO_LOGIC_STATE VAR WORD
'TURN SIGNAL VARIABLES LEFT_TURN_FLAG VAR BIT
RIGHT_TURN_FLAG VAR BIT
LTBIT VAR BIT
RTBIT VAR BIT
FLASHERS_FLAG VAR BIT
TURNINGLEFT_FLAG VAR BIT : TURNINGLEFT_FLAG = 0
TURNINGRIGHT_FLAG VAR BIT : TURNINGRIGHT_FLAG = 0
TURNTIME VAR WORD : TURNTIME = 15 'AMOUNT OF TIME TURN SIGNALS WILL OPERATE
TURNTIME_CTR VAR WORD : TURNTIME_CTR = 0 'COUNTS HOW LONG TURN SIGNALS HAVE BEEN OPERATING
'
'TIMER VARIABLES
COUNT1CTR VAR BYTE 'Counter for high temperature warning
COUNT1 VAR BYTE
COUNT1 = 10
COUNT1ONOFF VAR BIT
'
LEFT_TURN_OUT VAR PORTB.5 : LOW LEFT_TURN_OUT
RIGHT_TURN_OUT VAR PORTB.4 : LOW RIGHT_TURN_OUT
IGNITION_POWER_OUT VAR PORTB.0 : LOW IGNITION_POWER_OUT ' VERIFIED
'
'***************************** Initialize Interrupts ***************************
'Setup interrupts
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler TMR1_INT, _tickint, PBP, YES
endm
INT_CREATE ; Creates the interrupt processor
ENDASM
;
T1CON = $11 ; Prescaler = 8, TMR1ON
@ INT_ENABLE TMR1_INT ; enable Timer 1 interrupts
;
'DISABLE TEST MODE FOR DS2408'S
owout ONEWIRE, 3, [$96,$29,$D1,$AE,$32,$00,$00,$00,$0E,$3C] 'eLighting
owout ONEWIRE, 3, [$96,$29,$A2,$65,$30,$00,$00,$00,$9A,$3C] 'eSwitch
'
'ESWITCH VARIABLES [$29,$A2,$65,$30,$00,$00,$00,$9A] '
SWITCH_DATA VAR BYTE '
RUN_SWITCH VAR SWITCH_DATA.4 '
RTURN_SWITCH VAR SWITCH_DATA.2 '
LTURN_SWITCH VAR SWITCH_DATA.1 '
'
'ELIGHTING VARIABLES [$29,$D1,$AE,$32,$00,$00,$00,$0E]
ELIGHTING VAR BYTE
FLASH VAR ELIGHTING.2 '
LTURN VAR ELIGHTING.3 '
RTURN VAR ELIGHTING.5 '
REV_ELIGHTING VAR BYTE
'
START:
'LOAD SWITCH STATUS INTO VARIABLE SWITCH_DATA
owout ONEWIRE, 1, [$55,$29,$A2,$65,$30,$00,$00,$00,$9A]
pause 10
owout ONEWIRE, 0, [$F0,$88,$00]
pause 10
OWIN ONEWIRE, 0, [SWITCH_DATA]
pause 10
'
RUN_ROUTINE:
IF RUN_SWITCH = 0 THEN
HIGH IGNITION_POWER_OUT
else
LOW IGNITION_POWER_OUT
ENDIF
'
LEFT_TURN_ROUTINE:
IF LTURN_SWITCH = 0 THEN 'LEFT TURN SWITCH IS PRESSED
ELIGHTING.3 = 0
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
LEFT_TURN_OUT = COUNT1ONOFF
ELSE
ELIGHTING.3 = 1
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
LOW LEFT_TURN_OUT
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
ENDIF
'
RIGHT_TURN_ROUTINE:
IF RTURN_SWITCH = 0 THEN 'RIGHT TURN SWITCH IS PRESSED
ELIGHTING.5 = 0
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
RIGHT_TURN_OUT = COUNT1ONOFF
ELSE
LOW RIGHT_TURN_OUT
ELIGHTING.5 = 1
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
ENDIF
'
FLASHERS_ROUTINE:
IF SWITCH_DATA.7 = 0 THEN 'TEMPORARY FLASHERS TEST ROUTINE
ELIGHTING.2 = 0
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
ELSE
ELIGHTING.2 = 1
OWOUT ONEWIRE, 1, [$55,$29,$D1,$AE,$32,$00,$00,$00,$0E]
OWOUT ONEWIRE, 2, [$5A,ELIGHTING,REV_ELIGHTING]
ENDIF
GOTO START
'
tickint:
' Interrupt routine to handle each timer tick and increment all counters

T1CON.0 = 0 ' Stop the timer
COUNT1CTR = COUNT1CTR + 1
TURNTIME_CTR = TURNTIME_CTR + 1
'
IF COUNT1CTR = COUNT1 THEN
COUNT1CTR = 0
COUNT1ONOFF = ~COUNT1ONOFF
ENDIF
'
IF TURNTIME_CTR = TURNTIME THEN
TURNTIME_CTR = 0
TURNINGLEFT_FLAG = 0
TURNINGRIGHT_FLAG = 0
ENDIF
'
T1CON.0 = 1 ' Start the timer
'
@ INT_RETURN
END

[mpgmike]

Observations as I see them:
- When writing to an Output, write to the LATx Register, not the PORTx;

LEFT_TURN_OUT VAR PORTB.5 : LOW LEFT_TURN_OUT

should be

LEFT_TURN_OUT VAR LATB.5 : LOW LEFT_TURN_OUT

- If you are attempting to Read an Input, you need to Set the TRIS bit:

TRISC = %00000000
ONEWIRE VAR PORTC.0 'PIN 15

I've never used the OWIN/OWOUT PBP commands, and the PBP3 Manual doesn't cover whether you need to address the TRISC.0 bit when changing from OWIN to OWOUT. Might try that.

[tumbleweed]

The OW routines are going to be timing sensitive so there's a good chance that the TMR1 intr is upsetting it.
You may have to disable interrupts during OW commands. In this case you could also just shut off TMR1.