PIC16F84A using pulsout and TMR0

[HenrikOlsson]

Hi,
I don't follow you on the math....
If you reload TMR0 with 12 each interrupt you'll get (256-12) * 256 = 62464uS between each interrupt.

What kind of accuracy do you need? With the prescaler set to 1:256 and a TMR0 reload value of 178 you'll get (256-178)*256 = 19968uS between each interrupt plus a little for the time it takes to reload.

Another way would be to use an external xtal for TMR0, with a standard 32.768 watch xtal and the prescaler set to 1:128, you'll get one interrupt each second.

MPLAB have a simulator where you can run the code, it has a stopwatch function that can be used to "measure" how long a certain piece of code takes. I've never used it myself.

/Henrik Olsson.

[mister_e]

Instead of using StopWatch, you may measure it in real-world. Use a scope and measure the time using an extra I/O.

Example:

High AextraIO
' code you need to evaluate
LOW AextraIO

You place your scope (or frequency meter, etc etc) on the AextraIO pin and you measure it.

something handy for your Timer Calc
http://mister-e.org/pages/utilitiespag.html

[DragonBall_6]

Thanks to the advice and reply, I really appreciated it.

From the interupt I know that I could add in the date.Such as day=day+1,month=month+1 and so on....

I have another matter which is WHERE can i store 365 sunrsie time?
My algoritm is just like that:-
1 jan 2006 the sunrise time is 6:10 motor start run and 2 jan 2006 the sunrise time is 6:15 and so on.

I know that it is impossible for me to store 365 data in the PIC16F84A eeprom.
Can I store my data into the program memory or RAM?????

Please advice and thanks you very much...

[mister_e]

you could save it to the codespace and play around the following
http://www.pbpgroup.com/modules/wfse...p?articleid=10

or, use an external EEPROM.

[DragonBall_6]

Hi all
Thanks for the reply.

Just now on the lab I have try to display the word in the LCD but NOT SUCCESS.
Below is the code I follow all the connection on the PBP manual using PIC16F84A. LCD is bought from the www.cct.com.my.


‘ Set LCD Data port
DEFINE LCD_DREG PORTA
‘ Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_DBIT 0
‘ Set LCD Register Select port
DEFINE LCD_RSREG PORTA
‘ Set LCD Register Select bit
DEFINE LCD_RSBIT 4
‘ Set LCD Enable port
DEFINE LCD_EREG PORTB
‘ Set LCD Enable bit
DEFINE LCD_EBIT 3
‘ Set LCD bus size (4 or 8 bits)
DEFINE LCD_BITS 4
‘ Set number of lines on LCD
DEFINE LCD_LINES 2
‘ Set command delay time in us
DEFINE LCD_COMMANDUS 2000
‘ Set data delay time in us

Pause 100 ' Wait for LCD to startup
LCDOut $fe, 1 ' Clear LCD screen
LCDOut "Hello" ' Display Hello

End

Please advice and thanks

[HenrikOlsson]

Hi,
Double check all connections. Do you have the pullup resistor on RA4?

/Henrik Olsson.

[mister_e]

AND never finsih your program with a single END... use a endless loop or PBP STOP.

    LCDOUT $FE,1,"Your stuff"
Loop:
    Goto Loop