Hi,

I want to build an application with two BDC Motors and one IR sensor.
I want bidirectional motor speed controll.
I want to controll this application with PIC microcontroller,
preferable with the PIC16F877A.

I find link on Microchip's website where are informations about how
to controll brushed DC Motors.
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2125&param=en542244

On this webpage from the 'Brushed DC Motor Design Flowchart' I can see
that that for me it's important the following things to get the
application works, because I want this way to build the application:

 * for controll of two BDC Motors is necessary 2 pc of H/W PWM
 * for controll speed of two BDC Motors is necessary Quadrature
   Encoders, that is MCU, that is External Logic, that is a PIC
   microcontroller.

Right?
However, what is H/W PWM?

On this web page at the bottom one can see the image of schematic for
this application and explanations for it. For me here the two seen
bellow are important:

 * For Bi-direction variable speed BDC motor control, a 2-phase
   full-bridge is used, requiring 4 PWM pins
 * The ECCP module has brushed DC motor control options built into
   it.

PIC16F877A has two 'Capture/Compare/PWM Modules', so it hasn't ECCP.
Is it enough these two CCP Modules for two BDC Motors in my
application?

RC1/T1OSI/CCP2 on pin #12 - RC1 can also be the Timer1 oscillator
input or Capture2 input/Compare2 output/PWM2 output.

RC2/CCP1 on pin #13 - RC2 can also be the Capture1 input/Compare1
output/ PWM1 output.

RC1/T1OSI/CCP2 on pin #16 - RC1 can also be the Timer1 oscillator
input or Capture2 input/Compare2 output/PWM2 output.

RC2/CCP1 on pin #17 - RC2 can also be the Capture1 input/Compare1
output/PWM1 output.

So I can conclude that that the PIC16F877A has 4 PWM pins, right?

Because the PIC16F877A doesn't have ECCP but CCP what is the
difference if one use PIC with ECCP and if one use just CCP?

Any advices will be appreciated!

--
Regards, Paul Chany
You can freely correct me in my English.
http://csanyi-pal.info


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