Society of Robots - Robot Forum

Software => Software => Topic started by: aruna1 on February 25, 2009, 06:24:12 AM

Title: generating pwm throgh non ccp pin in 16F877A
Post by: aruna1 on February 25, 2009, 06:24:12 AM

guys is it possible to generate pwm signal using non ccp pin (like E0) in PIC 16F877A?. I'm using both pwm pins(ccp1 & ccp2) to drive my robot and now i need to operate a servo. so if i use a loop to toggle a pin between high and low to generate a pwm signal will it damage my PIC? and will pwm signal generate by this method is precise?
thanks

Title: Re: generating pwm throgh non ccp pin in 16F877A
Post by: Admin on February 26, 2009, 10:22:22 PM

Quote

so if i use a loop to toggle a pin between high and low to generate a pwm signal will it damage my PIC? and will pwm signal generate by this method is precise?

Nope it won't damage anything. And in fact its my preferred way to control servos. Its very precise.

Title: Re: generating pwm throgh non ccp pin in 16F877A
Post by: ArcMan on February 27, 2009, 12:51:42 PM

Like admin said, it is the preferred way to drive servos.  If you do the math from the PIC data sheet, you'll find that the pulse width accuracy at 50 Hz (the typical servo update frequency) is not very good using the CCP hardware.