I am using the following code to count pulses on TMR1, implementing =
interrupts to pick up the pulses, and an interrupt on TMR0 to give a =
count period.  The idea is to create a tachometer which needs to be =
integrated into another system.  The counter works like a charm but TMR0 =
doesn't seem to work.  Help please.  I am sure it is one of the =
registers I need to be looking at but I can't figure which one.  I am =
using Let PIC Basic Plus.

Thanks=20

Simon

DEVICE 16F877 ' Set device to 16F877

DECLARE XTAL 20

ON_INTERRUPT GOTO IntCheck

' ## Configure LCD=20

DECLARE LCD_TYPE 0 ' Set LCD type =3D 0 or Alphanumeric
DECLARE LCD_DTPIN PORTB.4 ' Set PORTB.4~7 as LCD DT pins
DECLARE LCD_ENPIN PORTB.2 ' Set enable pin to PORTB.2
DECLARE LCD_RSPIN PORTB.3 ' Set RS pin to PORTB.3
DECLARE LCD_INTERFACE 4 ' Set 4 line interface
DECLARE LCD_LINES 2 ' Set LCD to have two lines

DIM myInt AS BYTE
DIM myStore AS BYTE
DIM myTMR AS WORD
DIM TMR0Count AS BYTE

TRISC=3D%00000000

T1CON=3D%00111111
INTCON=3D%11000000
OPTION_REG.3=3D0
OPTION_REG.2=3D1
OPTION_REG.1=3D1
OPTION_REG.0=3D1
PIE1.0=3D1

PRINT $FE,1 : DELAYMS 30 ' Clear the LCD
PRINT $FE,2 ' Set cursor at line 1,1
PRINT $FE,$0C ' Switch off cursor
myStore=3D0
myInt=3D0
TMR0Count=3D0

MainLoop:=20
myTMR.Lowbyte =3D TMR1L
myTMR.Highbyte =3D TMR1H
GOSUB ShowVals=20
GOTO MainLoop


ShowVals:
CURSOR 1,1
PRINT "myInt: ", @myInt, " "
CURSOR 2,1
PRINT "TMR0Count: ", @TMR0Count, " "
RETURN


IntCheck:
CONTEXT SAVE
IF PIR1.0=3D1 THEN
GOTO IntTMR1
ENDIF

IF INTCON.2=3D1 THEN
GOTO IntTMR0
ENDIF

GOTO IntExit

IntTMR0:
myInt=3DmyStore
myStore=3D0
TMR0Count=3DTMR0Count+1
INTCON.2=3D0
GOTO IntExit

IntTMR1:
myStore=3DmyStore+1
PIR1.0=3D0
GOTO IntExit

IntExit:
CONTEXT RESTORE

END

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