Originally Posted by
kvrajasekar
Hi Darrel,
Thanks lot,
Plz tell me, why u select FOSC32,whynot FOSC8.
I chose FOSC32 because I didn't know what crystal you were using.
If you had a 20mhz crystal FOSC8 would probably not work.
But even with a 4mhz crystal, FOSC32 will still work fine.
and my final ques is how to find the rising edge(tON) and Falling Edge(tOFF).I used the following code to find this,
This is a digital i/p,
go_vol1
btfss PORTB,0 ;checking whether porta pin is set or not
goto go_vol1 ;waiting
clrf TMR0
Duty_vol1
btfsc PORTB,0 ;keep monitoring rising edge
goto Duty_vol1
movf TMR0,0
movwf volt_val
Plz give me ur suggestion to use this code,If it is correct my work will get finish.
The code shown will wait for a rising edge, then measure the duration of the high pulse. if you add the same thing again for the low pulse, you'll have both values.
Code:
go_vol1
btfss PORTB,0 ; Wait for rising edge
goto go_vol1
clrf TMR0 ; clear TMR0 for high pulse
Duty_vol1
btfsc PORTB,0 ; keep monitoring high pulse
goto Duty_vol1
movf TMR0,0 ; put TMR0 value in W reg
clrf TMR0 ; clear TMR0 for low pulse
movwf tON ; save timer value to variable
Duty_vol2
btfss PORTB,0 ; keep monitoring low pulse
goto Duty_vol2
movf TMR0,0 ; put TMR0 value in W reg
movwf tOFF ; save timer value to variable
> And also i m using LCD interface.wat should be the minimum delay b/w the commands to LCD.
It varies from display to display. I think the average is around 1.6ms, but some are as high as 2.5ms for commands. 2.0ms is standard with 50us DATA delay.
hth,
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