external pwm control by micro controller

[Chullaa]

hello!

I have a pwm circuit that can be used to control speed of a motor. The duty cycle is set by variable resistor R1 manually. I want to control the duty cycle by using microcontroller (PIC16F877A) by either digital or analog ports. Is there any suggestion. Can i replace POT-meter with a BJT transistor in unity amplifying mode by changing its resistance.

oh another! i don't want to use PIC's build in PWM.


thanks
regards
Chulla

 

[Integrated]

Hi there,

You can use Digital POT , controlled with I2C. find it here:
Data Acquisition - Digital Potentiometers | Digi-Key

Best regards

 

[Chullaa]

thank you Integrated. I am beginner at u Controller and not familiar with I2C. can use built in pwm but some senior forbid me to use it cause it may fail at operation time practically.

 

[js]

PIC PWM Calculator & Code Generator
are you try with google?
pwm with pic - Google Search

 

[Integrated]

thank you Integrated. I am beginner at u Controller and not familiar with I2C. can use built in pwm but some senior forbid me to use it cause it may fail at operation time practically.

If you ask me, the first time you may think its difiicult but give it a search and use ready files like I2C.c, learn how to deal with different protocols. I'm sure you can do it and I'm sure you will feel fine afterwards