While loop on pwm module

[chitalula]

I want to incease the duty cycle until the volts on R4 is equal to three ( feedback voltage to the pic greater than 153) then at this volt i want to stop the duty cycle.
Problems
the duty cycle is increased but it didnt stop when R4 it reach volts, duty cycle it seems to go up to 100% and i dont want this to occur
Please.! I need some one to help me on this task


clear
DEFINE ADC_BITS 8
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 50
Feedback var word
ADCON1=%00000010
duty VAR WORD ' Duty cycle value (CCPR1L:CCP1CON<5:4>)
TRISA = %11111111
TRISB = %11111111
TRISC = %11111011 ' Set PORTC.2 (CCP1) to output
CCP1CON = %00001100 ' Set CCP1 to PWM
T2CON = %00000101 ' Turn on Timer2, Prescale=4
LED1 VAR PORTB.1
adcin 0, feedback

' Use formula to determine PR2 value for a 1KHz signal,
' 4MHz clock, and prescale=4. (4E6/(4*4*1E3))-1=249
PR2 = 249 ' Set PR2 to get 1KHz out

' Use formula to determine CCPR1L:CCP1CON<5:4> value for
' ends of range 0% to 100%. (249+1)*4*0=0 (0% value)
' (249+1)*4*1=1000 (100% value)
duty =0 ' Set duty cycle to 20%


while feedback>153
CCP1CON.4 = duty.0 ' Store duty to registers as
CCP1CON.5 = duty.1 ' a 10-bit word
CCPR1L = DUTY >> 2
duty = duty + 1 ' Increase duty cycle
' Since the total sweep of duty is 1000 (1000-0) and
' we are adding 1 for each loop, that results in 60
' steps min to max. 1 second divided by 60 = 1mS
Pause 1 ' Pause 1/60 of second

wend

End

6517

[aratti]

You don't read ADC (feedback) whitin the while loop.

Cheers

Al.

[HankMcSpank]

Also if you're increasing the PWM duty cycle & expecting the ADC'ed voltage to rise until a target is met, then I think you'd want it arranged like this...

while feedback<153 (in other words, while 'feedback' is less than 153 increase PWM duty cycle)

[chitalula]

Thanx alot HankMSpank and arrati, i did what you said and my problems have been solved.
I want to add something in this code, i want after the duty cycle being constant to giveout this duty cycle for 3ms and then to put off duty cycle for 1.5ms
Please do me a favour for this too