Counting led blinks..

[mister_e]

FYI, the missing % is a new Code Box forum feature...

[tacbanon]

Hi,
I searched in the forum and found a peice of code by Bruce...

DEFINE LCD_DREG PORTBDEFINE LCD_DBIT 0
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50
PAUSE 100


TRISA.4 = 1 ' RA4/T0CKI = input to TMR0 counter
TRISB.0 = 0 ' RB0 = output for LED
CMCON = 7   ' All digital


i var byte
i=0
' Assign prescaler to WDT for 1:1 prescale on TMR0
' TMR0 clock will be from your external input on RA4/T0CKI
' Increment on high-to-low transitions
 OPTION_REG = 111000
 
' If you prefer, then increment on low-to-high transitions
' OPTION_REG = 101000
Lcdout $fe, 128, "Counter: ", #i 
pause 100
Main:
    TMR0 = 0     ' Clear TMR0 count before start
    
Loop1:
    WHILE TMR0 = 0 ' Wait for high-to-low transition
    WEND           ' on RA4/T0CKI
    PORTB.0 = 1    ' LED on to indicate transition seen 
    i=i+1       ' Increment
    Lcdout $fe, 128, "Counter: ", #i   
    PAUSE 200
    PORTB.0 = 0    ' LED off
    GOTO Main      ' Start over
    END

Everytime I press RA.4 it toggle RB0, I also put a variable that will display the value to the LCD, from the code I observed (please correct me if I wrong).
a. Timer0 is selected
b. The signal entry is RA.4
c. It increments on low-to-high transitions
d. Pre scale value is 1:2 (000 of Bits 2,1)
d. The configuration setting used OPTION_REG = 111000

So if connect the multi coin acceptor to the RA.4 this should count the number of pulse?

thanks in advance,
tacbanon

[HenrikOlsson]

Hi,
Yes, that would work. I'd probably add a little pause directly after the WHILE-WEND loop to allow the coin acceptor to push out all the pulses before the code reads the timer.

As for the prescaler, yes, the bits indicate a a 1:2 ratio but since bit 3 is set the prescaler isn't assigned to TMR0 but to the WDT so you get a 1:1 ratio which is what you want in this case.

Steve,
Thanks for the heads-up on the % character, great feature... Must try/verify:

This is a test, percent char %00110011
This is a test, no percent char 00110011

And here's how my post looks in preview:


Looks fine in the preview. (Appologies to tachbanon for trying this here).
EDIT: And in the final post, I don't see a problem... Is it when there's a = infront?

OPTION_REG = %00110011

Again, looks fine in the preview.
EDIT: And in the final post.

/Henrik.

[tacbanon]

Hi, now I'm trying to incorporate the coin acceptor, but I observered that when I connect PULSE line to RA4..it continues to count, even if the device is turned off or if I touched the wire. Please see the attachment, I'm using easypic6. What do you think causing it?


regards,
tacbanon

[HenrikOlsson]

Hi,
Try adding a pullup or pulldown resistor on the input.

[tacbanon]

I tried both using the built in switch to enabled Pull up/down.. no changes.
Please see attach image, I'm using the blue wire.
thanks,
tacbanon

[tacbanon]

Hi, I finally got it right, what was missing was the GND. Thanks Henrik for the help, my next target is to run the codes on PIC18F4550..hope it wont be a problem.

regards,
tacbanon