Bug in GCB

[Edward LaBudde]

I am getting a strange error message associated with the PWMoff command.  If I try to comment out line 103 or 129 I get this message:
Error: Program is too large, cannot fit all subroutines into available program memory
Here is the code:

'Snow melt V 3.0 08-23-11
'Tried to remobe PWM for Snow Sensor
'Copyright E.V. LaBudde 2011
'Tested all modes 08-09-11 
'Chip model
#chip 16F88, 8      'Pic model and clock MHz
#config INTRC_IO    'Use internal Oscillator
Osctune = b'111110' 'works from 111000 to 000011
'Set the pin directions
dir portA.0 In  'Cold pin 17
dir portA.1 In  'Hot pin 18
dir portA.2 In  'Ambient Temp pin 1
dir portA.3 Out 'Heater pin 2
dir portA.4 Out 'Pump pin 3
dir portB.0 In  'New Snow signal pin 6 Tied to pin 8
dir portB.1 In  'Manual Heat mode pin 7
dir portB.2 In  'Snow pin 8
dir PortB.3 Out 'Test port Pin 9
dir portB.4 In  'Manual Circulate Mode Pin 10
dir portB.5 Out 'LCD pin 11
'set defines
#define SendAHigh Set PORTB.5 Off                   'Note Polarity for 4X20 Newhaven display
#define SendALow Set PORTB.5  On 
#define Cold An0
#define Hot An1
#define Temp An2
#define Heater PortA.3
#define Pump PortA.4
#define ManualMode PortB.1
#define Snow PortB.2
#define Test PortB.3
#define ManualCirc PortB.4
#define LCD PortB.5 
dim AmbientT as integer
dim WaterinT as integer
dim WateroutT as integer
dim AmbientTemp as word
dim E_timemin as word
dim DeltaT as word
dim DisplayAmbT as word
dim DisplayinT as word
dim DisplayoutT as word
dim WaterinTemp as word
dim WateroutTemp as word
dim MeltTime_s as word
dim MeltTime_m as word
dim MeltTime_L as word
'Set inital parameters
InitSer 1, r2400, 1, 8, 1, none, invert                 'LCD interface Positive going Standby bit 2400 baud
Set LCD = On                                            'Init LCD
wait 200 ms
Option_reg.7 = off                                      'Enable WPU
MeltTime_s = 0                                          'Zero Melt times
MeltTime_m = 0
MeltTime_L = 0
E_timesec = 0                                           'Zero Elapsed times
E_timemin = 0
E_timehrs = 0
Tons = 0
On Interrupt ExtInt0 Call SnowCheck
    
Standby:
    Set Pump = Off                                      'Turn system Off
    Set Heater = On                                     'Keep heater on to defrost
    E_timesec = 0                                       'Zero Elapsed times
    E_timemin = 0
    Ambient = ReadAD(Temp)                              'Read Ambient air sensor
    ReadTable Tconvert, Ambient, AmbientTemp            'Look up temeperature value
    AmbientT = AmbientTemp - 80                         'Correct for lack of negiative numbers in table
    call ReadWater                                      'Check Water Temp
    call StandbyDisplay                                 'Refresh display    
    Count = 0                                           'Zero Write counter for EEprom writer
    If ManualMode = Off and ManualCirc = On then Goto Manual    'Goto manual mode
    If ManualCirc = Off and ManualMode = On then Goto Circ      'Goto circulate mode
    If ManualMode = On and ManualCirc = On then nop     'Prevent going to neverland
    If ManualMode = Off and ManualCirc = Off then nop   'Prevent going to neverland
    If AmbientT > -25 then Goto Standby                 'Bypass fluid measurement
    Set Heater = Off
    Set Pump = On                                       'Circulate water to measure WaterinT
    wait 30 s
    Set Pump = Off
    Set Heater = On     
    call ReadWater      `                               'Read water temperature
    If AmbientT < -25 and WaterinT < -15 then Goto Warm 'Keep unit off for as long as possible
    Wait 1 h                                            'Do hourly
Goto Standby
'Subs
Manual:                                                 'Turn on system Checked 10-19-11
    Call TurnOns
    Set Pump = On
    Set Heater = On
    PWMOff                                              'Turn on heater on snow sensor
    If Snow = On then MeltTime_s += 1                   'record melt time
    MeltTime_m = MeltTime_s/60
    EPWrite 255, MeltTime_m                             'Record melt time
    call Elapsed_time                                   'Measure on time
    call ReadWater                                      'Read water temperature
    call ManualDisplay                                  'Refresh display
    call Write                                          'Measure DeltaT in 10 min intervals and write to EEprom
    If ManualMode = On then Goto Standby                
    Wait 673 ms                                 
Goto Manual
Circ:                                                   'Checked 10-19-11
    Set Pump = On
    Set Heater = Off
    call Elapsed_time                                   'Measure on time
    call ReadWater                                      'Read water temperature
    call CircDisplay                                    'Refresh display
    If ManualCirc = On then Goto Standby                
    Wait 713 ms                                 
Goto Circ
Heat:                                                   'Checked 10-19-11
    Call TurnOns
    Set Pump = On                                       'Turn on system
    Set Heater = On
    PWMOff                                              'Turn on heater on snow sensor
    If Snow = On then MeltTime_s += 1                   'record melt time
    MeltTime_m = MeltTime_s/60
    EPWrite 255, MeltTime_m                             'Record melt time
    call Elapsed_time                                   'Measure on time
    call ReadWater                                      'Read water temperature
    call HeatDisplay                                    'Refresh display
    call Write                                          'Measure DeltaT in 10 min intervals and write to EEprom     
    If Snow = Off then                                  'Clear snow and wait 30 min.
        Wait 30 m
        goto Standby
    End If
    Wait 685 ms
Goto Heat
Warm:                                                   'Checked 10-19-11
    PulseOut Test, 1 ms
    Set Pump = On                                       'Turn on system
    Set Heater = On
    call ReadWater                                      'Read water temperature
    call WarmDisplay                                    'Refresh display
    if WaterinT > 100 then goto Standby                 'Warm up water then turn off
    Wait 703 ms
Goto Warm
Sub SnowCheck
    wait 1500 ms
    If Snow = On then goto heat                     'Test for sensor fail
    If Snow = Off Then call FailDisplay
Return
Sub ManualDisplay
    call Clear
    serprint 1, "Mode:"
    serprint 1, "Man"
    serprint 1, " T"
    MeltTime_m = MeltTime_s/60
    Serprint 1, MeltTime_m
    Serprint 1, "m"
    call CommonDisplay
Return
Sub CircDisplay
    call Clear
    serprint 1, "Mode:"
    serprint 1, "Circ"
    call CommonDisplay
Return
Sub StandbyDisplay
    call Clear
    serprint 1, "Mode:"
    serprint 1, "Sby"
    EPRead 255, MeltTime_L
    Serprint 1, " MTime:"                                   'Read melt time
    Serprint 1, MeltTime_L
    call CommonDisplay
    Wait 1 s
Return
Sub WarmDisplay
    call Clear
    call First
    serprint 1, "Mode:"
    serprint 1, "Warm"
    call CommonDisplay
Return
Sub HeatDisplay
    call Clear
    call First
    serprint 1, "Mode:"
    serprint 1, "Heat"
    call CommonDisplay
Return
FailDisplay:
    call Clear
    call First
    serprint 1, "Mode:"
    serprint 1, "SENSOR FAILURE"
    call CommonDisplay
Goto FailDisplay
Sub CommonDisplay
    call second
    call Elapsed_time                                   'Measure on time
    serprint 1, "Ambient:"
    If AmbientT_H.7 = On then
    DisplayAmbT =  65536 - AmbientT
    Else
        DisplayAmbT = AmbientT
    End If
    If AmbientT_H.7 = On then
        serprint 1, "-"
        serprint 1, DisplayAmbT
    Else
        serprint 1, DisplayAmbT
    End If
    serprint 1, " ET:"
    serprint 1, E_timemin
    serprint 1, "m" 
    call Third
    If Waterin < 52 then
        DisplayinT =  65536 - WaterinT
    Else
        DisplayinT = WaterinT
    End If
    serprint 1, "WIn:"
    If WaterIn  < 52  then
        serprint 1, "-"
        serprint 1, DisplayinT
    Else
        serprint 1, DisplayinT
    End If
    call Fourth
    serprint 1, "WOut:"
    If Waterout < 52 then
        DisplayoutT =  65536 - WateroutT
    Else
        DisplayoutT = WateroutT
    End If
    If Waterout < 52 then
        serprint 1, "-"
        serprint 1, DisplayoutT
    Else
        serprint 1, DisplayoutT
    End If
    EPRead 254, Tons
    serprint 1, " Tons:"
    serprint 1, Tons
    'wait 1 s
Return
Sub ReadWater
    Waterin =  ReadAD (cold)
    ReadTable Tconvert, Waterin, WaterinTemp
    WaterinT = WaterinTemp - 80
    Waterout = ReadAD (hot)
    ReadTable Tconvert, Waterout, WateroutTemp
    WateroutT = WateroutTemp - 80
Return
  
Sub Elapsed_time
    E_timesec += 1                  'Seconds
    If E_timesec = 60 then
        E_timesec = 0
        E_timemin += 1              'Minutes
    end if
Return
Sub Write
    DeltaT = WateroutT - WaterinT
    EPWrite 0, DeltaT                   'Store first Delta T measurement
    If E_timemin % 10 = 0 then          'Measure DeltaT in 10 min intervals and write to EEprom     
        Count += 1
        EPWrite Count, DeltaT
    End If
Return
Sub TurnOns
    TurnOn +=1
    EPWrite 254, TurnOn
Return
Sub TestDisplay
Call Clear
    serprint 1, "First line"
    Call second 
    Serprint 1, "Second line"
    Call Third
    Serprint 1, "Third line"
    Call fourth
    Serprint 1, "Fourth line"
    wait 1 s
Return
'NewHaven Display utilities
Sub Clear
    sersend 1, 254  'start CMD
    sersend 1, 81   'clear screen
Return
Sub First
    sersend 1, 254  'start CMD
    sersend 1, 69   'First line
    sersend 1, 0
Return
Sub Second
    sersend 1, 254  'start CMD
    sersend 1, 69   'second line
    sersend 1, 64
Return
Sub Third
    sersend 1, 254  'start CMD
    sersend 1, 69   'Third line
    sersend 1, 20
Return
Sub Fourth
    sersend 1, 254  'start CMD
    sersend 1, 69   'Fourth line
    sersend 1, 84
Return
Sub Baud
    '1=300, 2=1200, 3=2400, 4=9600, 5=14.4k. 6=19.2k, 7=57.6k, 8=115.2k
    sersend 1, 254  'start CMD
    sersend 1, 97   'baud select
    sersend 1, 4    '9600-
    wait 100 us
Return
/code]

[Edward LaBudde]

Hugh, this is the second time I have post about this problem.  The first time it was necessary to comment out the HPWM command to make the error go away.  This time tying to comment out the PWMOff comment brings the error.  There is definitely something going on with the HPWM code!

BTW, I really love GCB!  It is a very useful and powerful tool .  This project is a controller for the hot water system I had put under the driveway this summer.  I hope I can get it finished before the snow flies.    When you get around to it it would be great to have a serprint command for Integer variables.  Thanks, Ed.

[Mauried]

Have a look at the LST file and see if GCB is leaving a large gap at the page boundary ie 07FF-0800.
Ive had this problem before where the code needs more than 1 page and it gets worse with chips with multiple pages like 16F88 and worse again with 16F886 / 887 .
The problem seems to be that GCB calculates the program size incorrectly and concludes that all the code wont fit.
Try adding some NOP instructions in the vicinity of the code thats causing the problem, ie near the HPWM commands and then see if the error dissapears.
You may need to add a lot , sometimes Ive needed 64 or more.
Add them in lots of 8.

[Edward LaBudde]

Mauried, I think you are correct!  I added some new features to the code and increased the code size from 2830 bytes to 3396 and the problem went away!  There is definitely a bug in there somewhere.  Ed.

[kent_twt4]

Ed,  If your heater control ends up needing extra PWM resolution, the 18f1330 can give you up to 14 bits to play with.  Drop in replacement for the 16f88, 3 hardware PWM's, and no paging issues that I'm aware of.  I could post some PWM manual setup code if you go down that road, it's a totally different beast.

[Edward LaBudde]

Kent, Thanks for the tip.  I have changed the design so that I no longer need the PWM.  Ed.

[Edward LaBudde]

Kent, I think I will take you up on your offer,  There is an article in Circuit Cellar this month on a high accuracy voltage reference using an LT 1236 reference regulator.  A 14 bit PWM would be great.  Please post your code.  Thanks, Ed.

[Nobody/Anonymous]

Ed, no problem.  Here is the hardware PWM code that exercises a Futaba servo motor.  The Fpwm  and PTPER will be different for a standard PWM.  Hope the comments will make sense when comparing to the datasheet.  Let me know if something is amiss, it's been awhile since I did this.

;Servo code using the hardware Power PWM module of the PIC18f1330
#chip 18f1330, 4
#config osc=INTIO2,HPOL=HIGH,LPOL=HIGH 'set PWM polarity bit for active high
#define Servo PortB.1   ;Futaba s3003 servo 
#define forward 570     ;500?
#define neutral 330     ;375?
#define reverse 90      ;250?
dim PDC0 as word alias PDC0H, PDC0L
dim PTPER as word alias PTPERH, PTPERL
dim forward as word
dim neutral as word
dim reverse as word
init_PowerPWM
#define WaitLed wait 1 s    '5 10ms
Main:
PDC0 = forward
wait 3 s
PDC0 = neutral
wait 3 s
PDC0 = reverse
wait 3 s
goto Main
sub init_PowerPWM
    SET PTEN OFF    ;Turn off the timer base
    ;set PTCON0 bits
    SET PTOPS3 OFF  ;Time base output postscale bits
    SET PTOPS2 OFF
    SET PTOPS1 OFF
    SET PTOPS0 OFF
    SET PTCKPS1 ON  ;Time base input prescale bits
    SET PTCKPS0 OFF  ;PRESCALE bits: 11= 1/64, 10=1/16 , 01=1/4, 00=1/1 
    SET PTMOD1 OFF  ;Time base mode select bits
    SET PTMOD0 OFF  ; 00=free running, 01=single shot, 10=up/dn, 11=up/dn double update
    ;set PTCON1 bits
    SET PTDIR ON ;PWM TIME BASE count direction: 0=counts up, 1=counts down
    ;PWMCON0 PWM control register
    SET PWMEN2 OFF  ;PWM module enable bits
    SET PWMEN1 OFF  ;001 is PWM1, 110 is PWM1 &pwm3
    SET PWMEN0 ON
    SET PMOD2 OFF   ;PWM output pair mode pins
    SET PMOD1 OFF   ;0= independent mode
    SET PMOD0 OFF   ;1 = complementary mode 
    'PWMCON1 PWM control register, no deadtime or special interrupts set
    ;*************************************************************************************
    ;* PTPER = (Fcy/(Fpwm*PTMRPrescaler))-1
    ;* Fcy = Fosc/4
    ;* for 20ms or 18ms servo update
    ;* Fpwm = 1/.020 or 1/.018 = 50 or 55.55Hz
    ;* PTPER = (1000000/(50*16))-1 = 1249 (12 bit no. max (i.e. 0xFFF for 18f))
    ;*************************************************************************************
    ;could up the INTOSC to 8Mhz and PTPER=2499?
    PTPER = 1249
    ;*************************************************************************************
    ;* Servo duty cycle is 1-2ms over the 20ms period or,
    ;* 1/20*4*PTPER 'full reverse', 1.5/20*4*PTPER 'neutral', 2/20ms*4*PTPER 'full forward'
    ;* to get the correct duty cycle must multiply by 4 because of Q1:Q0 in PTMR register
    ;* PDCx (PDCxH and PDCxL) will be forward = 500, neutral = 375, reverse = 250 
    ;*************************************************************************************
    PDC0 = 0
    ;PDC1 = 0
    ;PDC2 = 0
    SET PTEN ON     ;Start up the timer base
end sub

[Mauried]

If you need a better voltage referance then a Microchip MCP1541 is the answer.
Its a high precision 4.096 V referance intended for 10 bit A/D apps.
The 4.096 V allows easy math to display voltages as 1 bit = exactly 4 mv.