What does this error message mean?

[keithv]

I'm using the PIC16F684. The previous version of this code worked just fine when the PT2399 delay chip had a very precise delay time, but they have become inconsistent which causes the tap tempo feature to be slightly out of sync with the delay time. I'm trying to add a "calibration" feature to sync the actual delay time with the tap tempo by adding or subracting postions on the digital potentiometer.

I've reposted the code and highlighted the parts that have been added or modified in blue. Here's a link to the schematic http://byocelectronics.com/echoroyalschematic.pdf The idea is that if the user is holding down SW2 during power up, it will go into "calibration mode". SW2 should now add 1 movement on the digital pot and SW1 should remove one movement. Holding down SW2 for 3 seconds should WRITE calibrationcounter to memory and return to normal function.

I forgot to mention the VR6 "tap multiplier" function, in case you're wondering what all the weird lookup tables are there for. This is a feature commonly requested by guitar players when using a delay/echo effect. It's used with the tap tempo. It sets the delay time so that the echoes will beat at straight quarter note, dotted eighth note, triplet, or 16th intervals and the user only needs to tap out a straight quarter note beat.

#config 

    __CONFIG _CP_OFF & _WDTE_OFF & _BOREN_OFF & _PWRTE_ON & _INTRC_OSC_NOCLKOUT & _MCLRE_OFF

#endconfig



ADCON0 = %00000000

ADCON1 = %00110000

ANSEL = %00000110

define ADC_SAMPLEUS 50

define ADC_BITS 8

DEFINE ADC_CLOCK 3

CMCON0 = %00000111         

TRISA = %00001111       

TRISC = %00000000

  

   

    ' Set TMR0 interrupt prescaler to 1:32

    OPTION_REG = %10000100        ' Set TMR0 configuration and enable PORTB pullups

    INTCON = %10100000           ' Enable TMR0 interrupts

    On Interrupt Goto tickint

    define WRITE_INT 1

   

    '                     

    '    Hardware connection

    '    ===================

    CS          VAR PORTA.5

    SCK         VAR PORTC.2

    SDI          VAR PORTC.1

    tempoLED var PORTC.0

    tempobutton var PORTA.0     

    bypassbutton var PORTA.3    

    bypassLED var PORTC.4

    fetA var PORTC.5

    fetB var PORTA.4

    fetC var PORTC.3

    ;pot is on   porta.2  an2

   

   

    '  

    '    Variables definition

    '    ===================

    x var word

    y var word

    w var byte 

    z var byte

    a var byte              ' ADC in variable for tempo LED calibration

    b var byte              ' tempo LED calibration variable used in main program

    c var byte              ' ADC in variable for tap calibration

    d var byte              ' tap calibration variable used in main program

    plusORminus var bit

    plusORminus1 var bit

    plusORminus2 var bit

    plusORminus3 var bit                

   

    ticks var word

    LEDcounter var word     

    LEDrate var word

   

    trailsmodecounter var word

    trailsmode var bit

    xprevious var byte

    override var bit

    analogpot var bit

    footswitch var bit

    analogpot = 1

    footswitch = 0

    LEDadj var byte

    LEDadj1 var byte

    tapadj var byte

    tapadj1 var byte

    calibrationcounter var byte

    calibrationon var bit


    '                 Calibration check

'================================================================

calibrationon = 0

read 1, calibrationcounter

if bypassbutton = 0 then         'hold down bypass button on power up to calibrate

    goto bypassbuttonrelease

    calibrationon = 1

endif

                           

    '

    '    begin in "bypass" state

    '    ====================

   

    tempoLED = 0

    fetA = 0

    fetB = 0

    fetC = 1

    bypassLED = 0

    trailsmode = 0

    override = analogpot

    pause 1000

    gosub readpot

    gosub movepot

    pause 100

   

   

'                     MAIN PROGRAM

'=================================================================   

main:

    gosub potcheck

    if LEDcounter < 3  then

            tempoLED = 1

        else

            tempoLED = 0

        endif

       

    if tempobutton = 0 then

        if calibrationon = 1 then

            goto subtractfromcalibrationcounter

        else

            goto tempopress

        endif

    endif

   

    if ticks > 400 then

        ticks = 300

    endif

   

    if LEDcounter > LEDrate then

        LEDcounter = 0

    endif

   

    if bypassBUTTON = 0 then

            if calibrationon = 1 then

                gosub addtocalibrationcounter

            else

                gosub bypasspress

            endif

            gosub bypassbuttonrelease

    ENDif

   

goto main

potcheck:      

       gosub readpot

       if abs (xprevious-x) > 4 then

            override = analogpot

            gosub movepot

       endif

return

readpot:

    adcin 1,x

    x = x * 10

    x = x/17

    'x = 1 max x

    

return





movepot: 
        x = x + calibrationcounter

        CS = 0

        shiftout SDI, SCK, 1, [00000000,x]

        shiftout SDI, SCK, 1, [00010000,x]

        CS = 1
        x = x - calibrationcounter

        if override = analogpot then                    'checks to see if the delay time was set by the pot or switch

            xprevious = x

        endif

        gosub tempoLEDadjust

return



tempoLEDadjust:                                           '  compensate for TMR0 not being 1:1 with actual delay time

  

   if x < 25 then

        LEDrate = x + 16

   elseif x >= 25 and x < 50 then

        LEDrate = x + 18

   elseif x >= 50 and x < 75 then

        LEDrate = x + 20

   elseif x >= 75 and x < 95 then

        LEDrate = x + 22      'noon to 2 o'clock

   elseif x >= 95 and x < 130 then

        LEDrate = x + 24    '2 o'clock to 3 o'clock

   elseif x > 130 then

        LEDrate = x + 26    '3 o'clock to FTCW

   endif

   

return



tempopress:

    if ticks >= 180 then              ' if longer than 3 45bpm since last press assume this is first press and start ticks counter over

        ticks = 0

        gosub tempobuttonrelease

        goto main

    endif

   

    if ticks <= 157 and ticks > 60 then              '  set delay time on this press based on how much time has elapsed since last press

        x = ticks - 20                  ' compensate for TRM0 being slightly faster than 10ms when tempo is slower than 100bpm

        gosub division

        override = footswitch

        gosub movepot

        ticks = 0

        gosub tempobuttonrelease

        goto main

    endif

   

    if ticks <= 60 and ticks > 57 then      'tempo between 100bpm and 110bpm

        x = ticks - 7                  

        gosub division

        override = footswitch

        gosub movepot

        ticks = 0

        gosub tempobuttonrelease

        goto main

    endif

   

    if ticks < 57 and ticks > 15 then          'tempo faster than 110bpm

        x = ticks - 15                  

        gosub division

        override = footswitch

        gosub movepot

        ticks = 0

        gosub tempobuttonrelease

        goto main

    endif

   

    if ticks < 180 and ticks > 157 then     ' if tap duration is slighlty longer than max delay time, then set to max delay time.

        x = 157 - 7

        gosub division

        override = footswitch

        gosub movepot

        ticks = 0

        gosub tempobuttonrelease

        goto main

    endif

   

    if ticks <= 15 then          'tap too fast

        x = 3                  

        gosub division

        override = footswitch

        gosub movepot

        ticks = 0

        gosub tempobuttonrelease

        goto main

    endif

                      

goto main



division:                                                          ' tap multiplier subroutine

    div var byte

    adcin 2, w                                                      ' read toggle switch on channel 1 and store in w

    if w < 51 then                                                     ' 1:1 ratio or quarter note

         x = x

    endif

   

    if w >= 51 and w < 102 then                                 ' 1:1.5 ratio or dotted eigth note

        lookup x, [1,1,1,1,1,1,1,1,1,2,2,2,3,3,4,5,6,7,7,8,9,10,11,12,13,13,14,15,15,16,16,17,17,17,18,19,19,20,21,22,22,23,_

        24,24,25,25,26,27,28,28,29,30,30,31,33,33,34,35,35,36,37,37,38,38,39,39,40,40,41,42,42,43,44,45,46,47,47,48,49,_

        50,50,51,51,52,52,53,54,54,55,55,56,57,58,58,60,60,61,61,62,63,63,64,65,66,66,66,67,68,69,69,69,70,71,72,72,72,73,74,75,75,75,_

        76,77,77,78,78,79,80,81,82,82,82,82,83,84,84,85,86,86,87,88,89,89,90,91,92,92,92,93,93,94,94], div

        x = div

    endif                                               

   

    if w >= 102 and w < 153 then                                 '1:2 ratio or eigth note

        lookup x, [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8,9,10,11,11,12,13,14,14,15,_

        15,15,16,16,16,17,17,18,18,19,19,20,20,21,22,22,23,23,23,24,24,25,25,25,26,26,27,27,28,28,29,29,30,31,32,33,33,34,34,35,35,36,36,_

        37,37,38,39,39,39,40,40,41,42,42,42,43,43,44,44,45,45,46,46,46,47,47,48,48,48,49,49,50,50,51,51,52,53,53,53,54,54,54,55,55,55,57,_

        57,58,58,58,58,60,60,60,60,62,62,62,62,4,64,64,64,66,66,66,66,68,68,68,68], div

        x = div

    endif

                 

    if w >= 153 and w < 204 then                                '1:3 ratio (triplets)

        lookup x, [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,3,3,3,4,_

        4,4,5,5,5,5,6,6,7,7,7,8,8,9,9,10,10,11,11,12,12,12,13,13,13,14,14,14,15,15,15,16,16,16,17,17,17,17,17,18,18,19,19,_

        20,20,20,21,21,21,22,22,22,23,23,23,24,24,24,25,25,25,26,26,26,26,27,27,27,27,27,28,28,28,29,29,30,30,30,31,31,32,33,33,33,34,_

        34,35,35,35,35,36,36,36,36,37,37,37,37,38,38,38,38,39,39,39,39,40,40,40,40], div

        x = div

    endif

               

    if w > 204 then                                             ' 1:4 ratio or 16th note

        lookup x, [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,_

        3,3,3,3,3,4,4,4,4,4,5,5,5,5,5,6,6,6,6,6,7,7,7,8,8,9,9,9,10,10,11,11,12,12,12,12,13,13,13,14,14,14,14,15,15,15,15,16,16,16,16,16,_

        17,17,17,17,17,17,18,18,18,18,19,19,19,19,20,20,21,21,21,21,21,21,22,22,22,22,23,23,23,23,24,24,24,24,24,25,25,25,25,25,25,26,26,26,_

        27,27], div

        x = div

    endif

    

    return



tempobuttonrelease:                                          ' debounce subroutine for tempo button

    returnTOpotCounter var word

    returnTOpotCounter = 0

    tempoLED = 1

    do until returnTOpotCounter >= 200

        if tempobutton = 1 then exit

        pause 10

        pause 10

        pause 10                                            ' pause 30ms.  Break up into 10ms to not interfer with interrupt timer

        returnTOpotCounter = returnTOpotCounter + 3

    loop

    tempoLED = 0

    pause 10

    pause 10

    pause 10

   

    if returnTOpotCounter >= 200 then

        gosub returnTOpot

    endif   

return



returnTOpot:

    gosub readpot

    gosub movepot

    onORoff var bit

    onORoff = bypassLED

    m var byte

    for m = 1 to 5

    bypassLED = 1

        pause 200

    bypassLED = 0

        pause 200

    next m

    bypassLED = onORoff

return                                                           



bypasspress:

    pause 10

    pause 10

    trailsmodecounter = 0                                      ' waits to see if you want to switch between normal or trails mode

    do until trailsmodecounter = 200

        if bypassbutton = 1 then exit

        pause 10      

        trailsmodecounter = trailsmodecounter + 1

    loop

   

    if trailsmodecounter = 200 then

        goto trailmodechange

    endif

   

    if trailsmode = 1 then

        gosub trailsbypass

    elseif trailsmode = 0 then

        gosub normalbypass

    endif

return



trailmodechange:                                                ' subroutine that occurs when bypass button is held long enough to change between normal or trails mode

    if trailsmode = 1 then

        trailsmode =  0

    elseif trailsmode = 0 then

        trailsmode = 1

    endif

   

    for z = 1 to 5

    tempoLED = 1

        pause 200

    tempoLED = 0

        pause 200

    next z

   

goto main   



normalbypass:                                                       ' subroutine for normal bypass

    if bypassLED = 0 then

        fetA = 1

        fetB = 1

        fetC = 0

        bypassLED = 1

    elseif bypassLED = 1 then

        fetA = 0

        fetB = 0

        fetC = 1

        bypassLED = 0

    endif

return



trailsbypass:                                                       'subroutine for trails bypass

    if bypassLED = 0 then

        fetA = 1

        fetB = 1

        fetC = 0

        bypassLED = 1

    elseif bypassLED = 1 then

        fetA = 0

        fetB = 1

        fetC = 1

        bypassLED = 0

    endif

return



bypassbuttonrelease:                                               '  debounce subroutine when bypass button is pressed

    do until bypassbutton = 1

        pause 10

        pause 10

        pause 10

    loop

return 



addtocalibrationcounter:

    bypassbuttoncounter var word

    bypassbuttoncounter = 0

    do until bypassbutton = 1

        pause 10

        pause 10

        pause 10

        bypassbuttoncounter = bypassbuttoncounter + 1

    loop

    if bypassbuttoncounter > 200 then

        write 1, calibrationcounter

        calibrationon = 0

    else

        calibrationcounter = calibrationcounter + 1

    endif

return


subtractfromcalibrationcounter:

    calibrationcounter = calibrationcounter - 1

    do until tempobutton = 1

        pause 10

        pause 10

        pause 10

    loop

return



Disable                                 ' Disable interrupts during interrupt handler

tickint:                                    ' Interrupt routine to handle each timer tick     

    ticks = ticks + 1

    LEDcounter = LEDcounter + 1

tiexit:

   INTCON.2 = 0                             ' Reset timer interrupt flag

   Resume

enable

end