hello

[imisendo_4036]

do anyone know how to set the reference speed in pic???
can anyone xplain???

 

[kchriste]

You mean the clock speed? It depends on the PIC and whether you want to use an external crystal or the internal oscillator. What PIC are you using?

 

[imisendo_4036]

i juz want to make a reference speed for my dc motor controller..
then the reference speed will be compare wif the current speed it running at..
actually i want to maintain my dc motor'speed
can u xplain hot to make it...
is't correct if i declare reference = 8x5/256
i'm using pic16f873....
n i'm using resonator(external)....

 

[AtomSoft]

2 things

1. Single Post (erase other one) (click edit then delete)
2. Type slow and check spelling. I can barely read what you wrote.

i juz want to make a reference speed for my dc motor controller..
then the reference speed will be compare wif the current speed it running at..
actually i want to maintain my dc motor'speed
can u xplain hot to make it...
is't correct if i declare reference = 8x5/256
i'm using pic16f873....
n i'm using resonator(external)....

I just want to make a reference speed for my DC motor controller.
Then the reference speed will be compared with the current speed it is running at.
Actually i want to maintain my DC motor's speed

Can you explain how to make it?
Is it correct if i declare reference = 8x5/256
Also i am using a PIC16F873 and a external resonator.

Now can't you read that better?

To be honest i can't help you here but i am sure you will get help if you just ask the right way.

 

[imisendo_4036]

sorry for the mistake...
ok actually i'm trying to make a source code to control dc motor's speed(to maintain speed)...but the prob is i do not know how to set the reference speed in my microcontroller....i'm using PIC16f873...
is it correct if i declare reference = 8x5/256 to get reference speed = 0.156V
or what should i do to set the reference speed??

 

[kchriste]

What are you using to measure the speed with? optical encoder? ADC and another dc motor? motor back EMF? etc....
Post a schematic. That'll make coding advice more relevant.

 

[imisendo_4036]

this is the schematic...

i'm using dc motor also for the speed detection...
i already try simulate using isis's software...but i dont know how to connect both dc motor...n all my led on once i run the simulation with both of the motor separate...can anyone xplain????plzzz

 

[imisendo_4036]

this is the schematic link...

https://i36.photobucket.com/albums/e12/zikry85/litar.jpg

 

[kchriste]

Hmmmm... This circuit and code looks familiar:
code:
**broken link removed**
Main page:
**broken link removed**
Why don't you follow the instructions on the site?

 

[imisendo_4036]

i have....but the explanation is not clear..
i do not know how to setting the frequency...
in the pic tutorial also not xplain more detail...
do u know any tutorial site about how to setting frequency,period of pwm etc for pic

 

[kchriste]

The frequency is set by the code and the crystal connected to pins 9&10 of the pic16f873. See the highlighted code below:

;*** PWM initialization
        clrf    tmr2            ;Clear TMR2 register
        movlw   b'11111111'     ;Max duty (low speed)
        movwf   ccpr1l          ;Set CCPR1L register
        bsf     status,rp0      ;Change to Bank1
        [COLOR="Red"]movlw   d'255'          ;Period=1638.4usec(610Hz)
        movwf   pr2             ;Set PR2 register[/COLOR]
        bcf     status,rp0      ;Change to Bank0
        movlw   b'000001[COLOR="Red"]10[/COLOR]'     ;Pst=1:1 TMR2=ON [COLOR="Red"]Pre=1:16[/COLOR]
        movwf   t2con           ;Set T2CON register
        movlw   b'00001100'     ;CCP1XY=0 CCP1M=1100(PWM)
        movwf   ccp1con         ;Set CCP1CON register

Isn't the code with the original author's comments much easier to read?