PWM feature doubt - Electronic Circuits Projects Diagrams Free

raviram87 · 5th April 2008, 04:46 PM

i was working on producing a carrier wave using the PWM feature of the PIC16f877a...

however i have few doubts on this.... i have used the PWM calculator provided by http://www.micro-examples.com for calculating the values to be loaded on to various registers....

i obtained the values and verified that they are correct using the formulas given in the datasheet... however i noticed the follwing written...

ENSURE THAT THE PWM PIN IS CONFIGURED AS DIGITAL OUTPUT...

what is the meaning of this statement? i will be taking the PWM output from pin number 17(CCP1)... do i have to include any specific statement in my code to do the above??

blueroomelectronics · 5th April 2008, 04:47 PM

You have to set the TRIS on that pin to 0 (zero)

raviram87 · 6th April 2008, 03:09 AM

many thanks...

i will be using this carrier generated at CCP1 pin to modulate few data pulses i will be producing at pin number 21 (RD2) of the 16f877a....

in that case should i configure that pin (#21) as digital output also?

when i am using CCP1 pin... what should be done with the CCP2 pin (#16)...

blueroomelectronics · 6th April 2008, 03:56 AM

Unless you set CCP2 to run as a second PWM channel you can just treat it like any other I/O pin.

5th April 2008, 04:46 PM	(permalink)
raviram87 Experienced Member	PWM feature doubt i was working on producing a carrier wave using the PWM feature of the PIC16f877a... however i have few doubts on this.... i have used the PWM calculator provided by http://www.micro-examples.com for calculating the values to be loaded on to various registers.... i obtained the values and verified that they are correct using the formulas given in the datasheet... however i noticed the follwing written... ENSURE THAT THE PWM PIN IS CONFIGURED AS DIGITAL OUTPUT... what is the meaning of this statement? i will be taking the PWM output from pin number 17(CCP1)... do i have to include any specific statement in my code to do the above??

5th April 2008, 04:47 PM	(permalink)
blueroomelectronics Experienced Member Blog Entries: 4	You have to set the TRIS on that pin to 0 (zero) __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

6th April 2008, 03:56 AM	(permalink)
blueroomelectronics Experienced Member Blog Entries: 4	Unless you set CCP2 to run as a second PWM channel you can just treat it like any other I/O pin. __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

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6th April 2008, 03:09 AM	(permalink)
raviram87 Experienced Member	many thanks... i will be using this carrier generated at CCP1 pin to modulate few data pulses i will be producing at pin number 21 (RD2) of the 16f877a.... in that case should i configure that pin (#21) as digital output also? when i am using CCP1 pin... what should be done with the CCP2 pin (#16)...