interested in PWM generation code! here it is.

[raghun]

This code is for PWM generation without using mikroC functions. This code was developed using PIC16F684. U can use the required MCU frequency, prescalar, and PWM frequency and dutycycle by just replacing the values in #define at the begining of the program.This code has been developed for AN893 application for bidirectional DC motor control. You can modify the code for PWM generation according to your requirements. The rest of the source code for AN893 application would be posted in few days for any one interested.

Code: Select all

/******************************************************************************
****************Bi Directional DC motor Control using PIC16F684****************
****************Developed By Raghu Nandan Ravi*********************************
****************Date : 29th March 2006*****************************************

****************Technical Parameters:******************************************
Oscillator  Used    : Internal Oscillator 8MHz
PWM frequency       : To be input by the user
Prescalar           : To be input by the user
Duty Cycle         : To be input by the user

**********************Important Formula****************************************
PWM Period=(PR2+1)*4*TOSC*PRESCALAR
DC=CCPR1L:CCP1CON<5:4>*TOSC*PRESCALAR
Resolution=log(FOSC/FPWM*prescalar)/log2
*******************************************************************************/

#define MCU_frequency 8000000ul
#define tmr2_prescalar 4
#define PWM_frequency 4880
#define duty_cycle 0.50   //50% duty cycle

void configure_timer2(void);
void pwm_init1(void);
void configure_output(void);
unsigned char duty_cycle1(void);
unsigned char motor_forward(void);
unsigned char motor_reverse(void);

void main(void)
{
pwm_init1();
while (1)
{
motor_forward();         //run motor in forward direction
}
}

//Configure the Port pins as Output by clearing the TRISC pins
void configure_output(void)
{
   TRISC.F5=0;
   TRISC.F4=0;
   TRISC.F3=0;
   TRISC.F2=0;
}

void configure_timer2(void)
{
 PIR1.TMR2IF=0;
 T2CON=0X05;            //postscale of 1:1 and prescale of 1:4
 asm{
 TMR2_OVERFLOW:          //LABEL
 btfss PIR1,TMR2IF      //test for TMR2 overflow
 goto TMR2_OVERFLOW     //no!TEST AGAIN
 bcf PIR1,TMR2IF        //clear the flag bit and continue.
 }
}

//Run the motor in forward direction
unsigned char motor_forward(void)
{
unsigned int TEMP;
TEMP=duty_cycle1();
CCP1CON=TEMP+0X4C;
configure_timer2();
configure_output();
PORTC.F5=1;        //P1A active high continuosuly
PORTC.F4=0;
PORTC.F3=0;
PORTC.F2=1;        //P1D modulated ouput
}

unsigned char motor_reverse(void)
{
unsigned int TEMP;
TEMP=duty_cycle1();
CCP1CON=TEMP+0XCC;
configure_timer2();
configure_output();
PORTC.F5=0;
PORTC.F4=1;     //P1D modulated ouput
PORTC.F3=1;     //P1C active high continuosuly
PORTC.F2=0;
}

void pwm_init1(void)
{
unsigned int period_register;
TRISC=0XFF;         //set the ports initially to input
PORTC=0X00;
period_register= MCU_frequency/(PWM_frequency*4*tmr2_prescalar)-1;
PR2=period_register;
T2CON=0X00;         //set the timer2 initially to 0
INTCON=0X00;
PIE1=0;
PIR1=0;
OSCCON=0X75;
OSCTUNE=0X00;
TMR2=0;
}

unsigned char duty_cycle1(void)
{
unsigned int TEMP, control_register, CCP1CON_register,val,TEMPX,period_register;
   float duty_cycle2;
   duty_cycle2=duty_cycle/PWM_frequency;
   control_register=duty_cycle2*MCU_frequency/tmr2_prescalar;

   CCPR1L=control_register>>2;       //upper 8 bits of the 10 bits duty cycle resolution
   TEMP=control_register<<8;
   CCP1CON_register=TEMP>>8;
   CCP1CON_register&=0X03;
   switch(CCP1CON_register)
   {
   case 0:
   {
  TEMPX==0X00;
  break;
   }
    case 1:
   {
  TEMPX==0X10;
    break;
   }
    case 2:
   {
  TEMPX==0X20;
    break;
   }
    case 3:
   {
  TEMPX==0X30;
    break;
   }
   }
return TEMPX;
}

[pizon]

Nice and useful! Thanks, raghun.

[kavitham]

[quote="raghun"]This code is for PWM generation without using mikroC functions. This code was developed using PIC16F684. U can use the required MCU frequency, prescalar, and PWM frequency and dutycycle by just replacing the values in #define at the begining of the program.This code has been developed for AN893 application for bidirectional DC motor control. You can modify the code for PWM generation according to your requirements. The rest of the source code for AN893 application would be posted in few days for any one interested.

Code: Select all

/******************************************************************************
****************Bi Directional DC motor Control using PIC16F684****************
****************Developed By Raghu Nandan Ravi*********************************
****************Date : 29th March 2006*****************************************

****************Technical Parameters:******************************************
Oscillator  Used    : Internal Oscillator 8MHz
PWM frequency       : To be input by the user
Prescalar           : To be input by the user
Duty Cycle         : To be input by the user

**********************Important Formula****************************************
PWM Period=(PR2+1)*4*TOSC*PRESCALAR
DC=CCPR1L:CCP1CON<5:4>*TOSC*PRESCALAR
Resolution=log(FOSC/FPWM*prescalar)/log2
*******************************************************************************/

#define MCU_frequency 8000000ul
#define tmr2_prescalar 4
#define PWM_frequency 4880
#define duty_cycle 0.50   //50% duty cycle

void configure_timer2(void);
void pwm_init1(void);
void configure_output(void);
unsigned char duty_cycle1(void);
unsigned char motor_forward(void);
unsigned char motor_reverse(void);

void main(void)
{
pwm_init1();
while (1)
{
motor_forward();         //run motor in forward direction
}
}

//Configure the Port pins as Output by clearing the TRISC pins
void configure_output(void)
{
   TRISC.F5=0;
   TRISC.F4=0;
   TRISC.F3=0;
   TRISC.F2=0;
}

void configure_timer2(void)
{
 PIR1.TMR2IF=0;
 T2CON=0X05;            //postscale of 1:1 and prescale of 1:4
 asm{
 TMR2_OVERFLOW:          //LABEL
 btfss PIR1,TMR2IF      //test for TMR2 overflow
 goto TMR2_OVERFLOW     //no!TEST AGAIN
 bcf PIR1,TMR2IF        //clear the flag bit and continue.
 }
}

//Run the motor in forward direction
unsigned char motor_forward(void)
{
unsigned int TEMP;
TEMP=duty_cycle1();
CCP1CON=TEMP+0X4C;
configure_timer2();
configure_output();
PORTC.F5=1;        //P1A active high continuosuly
PORTC.F4=0;
PORTC.F3=0;
PORTC.F2=1;        //P1D modulated ouput
}

unsigned char motor_reverse(void)
{
unsigned int TEMP;
TEMP=duty_cycle1();
CCP1CON=TEMP+0XCC;
configure_timer2();
configure_output();
PORTC.F5=0;
PORTC.F4=1;     //P1D modulated ouput
PORTC.F3=1;     //P1C active high continuosuly
PORTC.F2=0;
}

void pwm_init1(void)
{
unsigned int period_register;
TRISC=0XFF;         //set the ports initially to input
PORTC=0X00;
period_register= MCU_frequency/(PWM_frequency*4*tmr2_prescalar)-1;
PR2=period_register;
T2CON=0X00;         //set the timer2 initially to 0
INTCON=0X00;
PIE1=0;
PIR1=0;
OSCCON=0X75;
OSCTUNE=0X00;
TMR2=0;
}

unsigned char duty_cycle1(void)
{
unsigned int TEMP, control_register, CCP1CON_register,val,TEMPX,period_register;
   float duty_cycle2;
   duty_cycle2=duty_cycle/PWM_frequency;
   control_register=duty_cycle2*MCU_frequency/tmr2_prescalar;

   CCPR1L=control_register>>2;       //upper 8 bits of the 10 bits duty cycle resolution
   TEMP=control_register<<8;
   CCP1CON_register=TEMP>>8;
   CCP1CON_register&=0X03;
   switch(CCP1CON_register)
   {
   case 0:
   {
  TEMPX==0X00;
  break;
   }
    case 1:
   {
  TEMPX==0X10;
    break;
   }
    case 2:
   {
  TEMPX==0X20;
    break;
   }
    case 3:
   {
  TEMPX==0X30;
    break;
   }
   }
return TEMPX;
}

[/quote





HI..

The code which is given by u is usefull.. but.. i need code in asm ... so.. pls.. send the code in asm..

[xor]

The code which is given by u is usefull.. but.. i need code in asm ... so.. pls.. send the code in asm..

Simply compile the above code with the compiler and copy the ASM in the compiler. It's close to MPASM but with some differences in how variables are used. If you need to convert it to MPASM then you can check out this ASM Translator by MAN:

http://www.ttelecom.com.br/translator/asmtrans/html/

[karishma4]

kindly provide with the full code for an893 for closed loop speed control