touch switch dimmer

[helmut]

hello everyone,
i am new in picbasic pro,recently i work on a project <touch switch dimmer>
i make 9 switches and connect them into pic 16f876,each output of the switch will give 0v or 5v.
1 switch is connected in portc.6 act as a selection button, when i touch it once,it control my LED brightness
second touch will goes to control my servo motor's speed

i arrange the rest of the 8 switches in circular shape and their output is connected to port B of my pic as a intensity controller. when i move clockwise, it will increase the brightness of the LED or the speed of the motor (depend on which 1 selected). If i move counter-clockwise,it will decrease the intensity.
and my output is pin CCP1 and CCP2,the output is connected to a RC filter then to the transistor and control the LED or the Motor circuit.
In this project, i try to use pwm to control the intensity,i need some idea to write the code...

before this,i try a code as below to test the pwm output,but it seem not work:
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' Output is a 1Khz signal with duty cycle sweeping
' from 20% to 80% once per second

' Note: PWM output will be on the CCP1 pin. Register
' names are for the PIC16F87x devices.

' PR2 = Timer2 period register, controls PWM period.
' CCPR1L and CCP1CON<5:4>bits control the duty cycle,
' and should be treated as a 10-bit word

' Fosc = Clock Frequency (4MHz)
' PS = Timer2 Prescale Value (T2CON<1:0>)
' Freq = PWM output frequency
' Duty% = Duty cycle (20% = 0.2)

' formulas:
' PR2=(Fosc/(4*PS*Freq))-1
' CCPR1L:CCP1CON<5:4>=(PR2+1)*4*Duty%

duty VAR WORD ' Duty cycle value (CCPR1L:CCP1CON<5:4>)


TRISC.2 = 0 ' Set PORTC.2 (CCP1) to output
CCP1CON = %00001100 ' Set CCP1 to PWM
T2CON = %00000101 ' Turn on Timer2, Prescale=4

' 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 20% to 80%. (249+1)*4*0.2=200 (20% value)
' (249+1)*4*0.8=800 (80% value)


duty = 200 ' Set duty cycle to 20%

loop: CCP1CON.4 = duty.0 ' Store duty to registers as
CCP1CON.5 = duty.1 ' a 10-bit word
CCPR1L = DUTY >> 2

duty = duty + 10 ' Increase duty cycle

' Since the total sweep of duty is 600 (800-200) and
' we are adding 10 for each loop, that results in 60
' steps min to max. 1 second divided by 60 = 16.67mS

Pause 17 ' Pause 1/60 of second

IF (duty < 800) Then loop ' Do it again unless 80% duty cycle

duty = 200 ' Reset to 20% duty cycle

GoTo loop ' Do it forever

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thank for your helps

[paul borgmeier]

before this,i try a code as below to test the pwm output,but it seem not work:

Your code looks fine (to me) - what is not working?
Do you get PWM out? Is the timing off?
Is the 1 second off?
Anything connected to RC2 during this test?

[helmut]

i put a LED as the output in RC2
i c no different for the intensity of the LED after i run this pwm code....
did i missed some step?

[Raflex]

You need to add DEFINE OSC 4, try with HPWM command.

[helmut]

thank you guys,i solve the pwm problems.that's minor mistake in my hardware.
In addtion, in my project, i move clockwise will increase intensity of my output.
and move counter clockwise will decrease the intensity.
so i try the shifting instruction
the code i used as shown:

if portb == portb>>1 then
high porta.0
endif
if portb == portb<<1 then
high porta.1
endif
end

if my 1st input is high in portb.0, it's consider shifting right or shifting left??