Counter not counting !!!

[lerameur]

Hi,

Ok I added an interrupt and wrote the program from what you said. Althouth I get zero on the LCD, seems that the interrupt is not working, can you help me debug it? Do I need to initialize some parameter . I am using the pic16f88
Ken


' Internal Oscillation program
' LCD
' Main loop display the counts and the interrupt routine counts

'/////////////////////////
'// Define section //
'/////////////////////////

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, INTRC_OSC, CCPMX_ON, MCLR_ON
OSCCON=$60 ' use internal 4MHZ osc

CMCON = 7 ' Turn OFF the comparators so pins can be used as digital I/O-pins

'///////////////////////////
'// Interrupt section //
'///////////////////////////
OPTION_REG = %00111000
'Transition on TOCKI (RA4),
'Increment on falling edge
'Prescalar assigned to WDT for a 1:1 TMR0 ratio.
INTCON.2 = 0 ' Clear Timer0 int flag
INTCON.5 = 1 ' Enable Timer0 int
TMR0 = $FF ' Set TMR0 to 255. So one more tick and TMROIF will be set.

'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTB ' Set LCD Data port
DEFINE LCD_DBIT 4 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 1 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 0 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits) '4 therefore put wire at 4, 5, 6 and 7 of LCD
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 1000


'/////////////////////////
'// PIN configuration //
'/////////////////////////

TRISA = %11110111 ' Set PORTA to all input
' Set PORTA.4 (TOCKI) to input for timer0
TRISB = %00001111 ' Set PORTB to all output
PortA = 0

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////

Revolution var word
Counter var word
oldCounter var word
feet var word
feet_left var word
feet_right var word

revolution = 0
Counter = 0
feet = 0
PortB.2 = 1 'Put to 5v via a resistor and a pushbutton to ground for reset

ON INTERRUPT GOTO LapCount

Mainloop:
if PortB.2 = 0 then
goto Reset_variables
endif

lcdout $FE,1, "Cter:",dec Counter, " Rev:",dec Revolution
lcdout $FE,$C0, "Feet:",dec feet/12, ".", dec2 feet//12 'This will save feet, and the // will print the decimal to two decimal point
pause 20
GOTO Mainloop

Reset_variables:
revolution = 0
Counter = 0
feet= 0
lcdout $FE,1, "Counter:",dec Counter , " Rev:",dec Revolution
lcdout $FE,$C0, "Feet:",dec feet/12, ".", dec2 feet//12
pause 20

GOTO Mainloop

disable
LapCount:
If INTCON.2 = 1 then
Counter = Counter + 1
endif
toggle PORTB.3
TMR0 = $FF ' Indicate we're in interrupt handler
INTCON.2 = 0 ' Clear TMR0 Interrupt Flag (Bit 2)

'Calculate the distance

if Counter =4 then
Revolution = Revolution + 1
Counter =0
endif

feet_left = Revolution *3
feet_right = Revolution *25
feet_right = feet_right / 100
feet= feet_left +feet_right

Resume
Enable
end

[lerameur]

by the way I connected the sensor to portA.4
ken

[Archangel]

Hi,

Ok I added an interrupt and wrote the program from what you said. Althouth I get zero on the LCD, seems that the interrupt is not working, can you help me debug it? Do I need to initialize some parameter . I am using the pic16f88
Ken


' Internal Oscillation program
' LCD
' Main loop display the counts and the interrupt routine counts

'/////////////////////////
'// Define section //
'/////////////////////////

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, INTRC_OSC, CCPMX_ON, MCLR_ON
OSCCON=$60 ' use internal 4MHZ osc

CMCON = 7 ' Turn OFF the comparators so pins can be used as digital I/O-pins

'///////////////////////////
'// Interrupt section //
'///////////////////////////
OPTION_REG = %00111000
'Transition on TOCKI (RA4),
'Increment on falling edge
'Prescalar assigned to WDT for a 1:1 TMR0 ratio.
INTCON.2 = 0 ' Clear Timer0 int flag
INTCON.5 = 1 ' Enable Timer0 int
TMR0 = $FF ' Set TMR0 to 255. So one more tick and TMROIF will be set.

'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTB ' Set LCD Data port
DEFINE LCD_DBIT 4 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 1 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 0 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits) '4 therefore put wire at 4, 5, 6 and 7 of LCD
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 1000


'/////////////////////////
'// PIN configuration //
'/////////////////////////

TRISA = %11110111 ' Set PORTA to all input
' Set PORTA.4 (TOCKI) to input for timer0
TRISB = %00001111 ' Set PORTB to all output
PortA = 0

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////

Revolution var word
Counter var word
oldCounter var word
feet var word
feet_left var word
feet_right var word

revolution = 0
Counter = 0
feet = 0
PortB.2 = 1 'Put to 5v via a resistor and a pushbutton to ground for reset

ON INTERRUPT GOTO LapCount

Mainloop:
if PortB.2 = 0 then
goto Reset_variables
endif

lcdout $FE,1, "Cter:",dec Counter, " Rev:",dec Revolution
lcdout $FE,$C0, "Feet:",dec feet/12, ".", dec2 feet//12 'This will save feet, and the // will print the decimal to two decimal point
pause 20
GOTO Mainloop

Reset_variables:
revolution = 0
Counter = 0
feet= 0
lcdout $FE,1, "Counter:",dec Counter , " Rev:",dec Revolution
lcdout $FE,$C0, "Feet:",dec feet/12, ".", dec2 feet//12
pause 20

GOTO Mainloop

disable
LapCount:
If INTCON.2 = 1 then
Counter = Counter + 1
endif
toggle PORTB.3
TMR0 = $FF ' Indicate we're in interrupt handler
INTCON.2 = 0 ' Clear TMR0 Interrupt Flag (Bit 2)

'Calculate the distance

if Counter =4 then
Revolution = Revolution + 1
Counter =0
endif

feet_left = Revolution *3
feet_right = Revolution *25
feet_right = feet_right / 100
feet= feet_left +feet_right

Resume
Enable
end

TRISA = %11110111 ' Set PORTA to all input
<font color=red> PortA.3 as output</font color>
' Set PORTA.4 (TOCKI) to input for timer0
TRISB = %00001111 ' Set PORTB to all output
<font color=red> PortB.0:3 as inputs</font color>
PortA = 0

For starters, check this to see if it is what you really want.
PortA.4 is Schmitt Trigger input so a pulldown resistor as shown in the opto's datasheet will be a necessity, it says it outputs min 3.0v so it should swing the S T input OK. The 16F88 has a ton of analog you need to attend to if you want to use it, I am not seeing any code to do that.

[lerameur]

Hi,

the hardware seems good, like I said it works at slow speed. In my case I have to use port RA4 right? to get the timer0 from my program.
I looked through the datasheet and nowhere there is mention on how to disable the schmitt trigger.

ken

[Acetronics2]

Hi, Ken

IF you want your Thing to work properly ...

You HAVE to use QUICK Interrupts and not " On Interrupt" ... especially if using a LCD.

So, Have a look to asm interrupts or Darrel Instant Interrupts ...

Alain

[Bruce]

Why not just let hardware handle most all of this for you?

' include your hardware/config stuff here

Revs VAR BYTE ' holds up to 255 revolutions
ANSEL = 0     ' disable A/D so RA4 is digital
CMCON = 7     ' disable comparators
OPTION_REG = %00110001 ' RA4 = count input
' inc count every 4th falling edge with 1:4 prescale
' assigned to TMR0

Mainloop:
    TMR0 = 0      ' clear count before pause
    PAUSE 20      ' Adjust this to set how long it counts revolutions here  
    Revs = TMR0   ' TMR0 counts 1 rev for every 4 pulses
    LCDOUT $FE,1,"Revs: ",DEC Revs

    ' do other stuff here, then return to get more counts
    GOTO Mainloop

This will be a LOT faster than interrupting on every single pulse, and counting
in software. You should be able to give the wheel a pretty good spin without
missing anything.

[lerameur]

HI, I am not able to make this code work, always leaves me with ORevs = 1 on the LCD.
I also change the oscillation to 20 Mhz but did not see any difference.
ken



' Internal Oscillation program
' LCD
' Main loop display the counts and the interrupt routine counts

'/////////////////////////
'// Define section //
'/////////////////////////

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, INTRC_OSC, MCLR_ON
OSCCON=$60 ' use internal 4MHZ osc
ANSEL = 0 : ADCON1 = 7
CCP1CON = 0 'CCP1 module off


'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTB ' Set LCD Data port
DEFINE LCD_DBIT 4 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 1 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 0 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits) '4 therefore put wire at 4, 5, 6 and 7 of LCD
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 1000


'/////////////////////////
'// PIN configuration //
'/////////////////////////

TRISA = %11111111 ' Set PORTA.4 (TOCKI) to input for timer0
TRISB = %00001111 ' Set PORTB
PortA = 0

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////

Revs var word
ORevs var word

ANSEL = 0 ' disable A/D so RA4 is digital
CMCON = 7 ' disable comparators
OPTION_REG = %00110001 ' RA4 = count input
' inc count every 4th falling edge with 1:4 prescale
' assigned to TMR0

Mainloop:
TMR0 = 0 ' clear count before pause
PAUSE 20 ' Adjust this to set how long it counts revolutions here
Revs = TMR0 ' TMR0 counts 1 rev for every 4 pulses
ORevs = Revs +1
LCDOUT $FE,1,"ORevs: ",DEC ORevs

GOTO Mainloop
end

[Bruce]

As Joe already mentioned earlier, RA4 T0CKI is a Schmitt Trigger input. If your sensor doesn't output a minimum voltage of 0.8 * VDD for logic 1 and 0.2 * VDD or less for logic 0, then the Schmitt Trigger input isn't seeing the correct logic levels, and TMR0 isn't counting your pulses.

Here's a quick little test program to show how it works when RA4/T0CKI is connected to an I/O-pin to increment the counter.

@ DEVICE pic16F88, INTRC_OSC, CCPMX_ON, MCLR_OFF

DEFINE HSER_BAUD 2400

Loops VAR BYTE
Revs var BYTE

OSCCON=$60 ' use internal 4MHZ osc

ANSEL = 0  ' disable A/D so RA4 is digital
CMCON = 7  ' disable comparators

TRISA.4=1  ' RA4/T0CKI = input (Timer0 clock input)
PORTB.5=1  ' USART TX pin idles high
PORTB.0=1  ' clock output pin to RA4 starts high
TRISB.0=0  ' clock out pin to RA4/T0CKI = output
TRISB.5=0  ' USART TX = output

ANSEL = 0     ' disable A/D so RA4 is digital
CMCON = 7     ' disable comparators
OPTION_REG = %10110001 ' clk on RA4/T0CKI, falling edge, 1:4 prescale

Mainloop:
    TMR0 = 0      ' clear count before each pass
    
    ' output 8 clocks on RB0 to RA4/T0CKI
    FOR Loops = 0 TO 7
      PORTB.0=1   ' RB0 connects to RA4/T0CKI
      PAUSE 5
      PORTB.0=0   ' counter increments on falling edge
      PAUSE 5
    NEXT Loops
      
    Revs = TMR0   ' get TMR0 count
    IF OPTION_REG.0 THEN
       HSEROUT ["Counts at 1:4 prescale: ",dec Revs,13,10]
    ELSE
       HSEROUT ["Counts at 1:2 prescale: ",dec Revs,13,10]
    ENDIF
    OPTION_REG.0 = OPTION_REG.0 ^ 1 ' toggle 1:4 or 1:2 prescale
    GOTO Mainloop 
    
    end

It works great, but only as long as the input signal meets the threshold levels the Schmitt Trigger input buffer on RA4/T0CKI expects.