- This topic has 5 replies, 3 voices, and was last updated 9 years, 12 months ago by
.
-
Posts
-
hi
i need some help with my next project its abut pwm iam using pic 16f877a
iam able to make pwm with it and now iam also able to change its duty cycle with 2 puch button . Now i what to change its frequency
with 2 button
so if you guys can help me a bit with the frequency changing stuff
Inorder to change the frequency, all you have to do is to change the sum period of the on – off time. If you your code and some description about the hardware connections, someone could help you better
Inorder to change the frequency, all you have to do is to change the sum period of the on – off time. If you your code and some description about the hardware connections, someone could help you better
Well iam using mikroC pro as my compiler an here are the code.s iam using to set up my frq iam using this
PWM1_init();
an for changing the duty iam using
PWM1_Set_Duty();
iam doing the incriment and decrement in the duty properly its working fine 0-255
but iam having some problem with the frq varying
if(RD1_Bit) {
Delay_ms(10);
PWM1_init(1000);
PWM1_Set_Duty();
}atm iam just runing it like this but i want to do proper increment and decrement in the frq like 1khz to 50khz
with the help on 2 buttons
Well iam using mikroC pro as my compiler an here are the code.s iam using to set up my frq iam using this
PWM1_init();
an for changing the duty iam using
PWM1_Set_Duty();
iam doing the incriment and decrement in the duty properly its working fine 0-255
but iam having some problem with the frq varying
if(RD1_Bit) {
Delay_ms(10);
PWM1_init(1000);
PWM1_Set_Duty();
}atm iam just runing it like this but i want to do proper increment and decrement in the frq like 1khz to 50khz
with the help on 2 buttons
hi,
i m able to make pwm but i can not change duty cycle of it using ADC module of 18f2431.
Can u help me?
I want that if my ADC of PIC18F2431 reading one variable pot. when i chage that pot, i should change the duty cycle of my pwm signals….
the code is : i m using MPLAB
#include<P18F2431.h>
#define MAX_DUTY_CYCLE 100 // 100% DUTY CYCLE PDC1=PDC2=PDC=499
#define MIN_DUTY_CYCLE 25 // 2.4% DUTY CYCLE PDC1=PDC2=PDC=499
//#define mydata2 ADRESH
void msdelay(unsigned int);
void chk_isr(void);
void AD_ISR();
#pragma code My_HiPrio_Int=0x0008 // high-priority interrupt
void My_HiPrio_Int(void)
{
// _asm
chk_isr();
// _endasm
}
#pragma code //end high-priority interrupt
#pragma interrupt chk_isr // which interrup?
void chk_isr(void)
{
if (PIR1bits.ADIF==1) //a/d cause interrupt?
AD_ISR(); // Yes, Execute INTO program
}
unsigned char DesiredPWMDutyCycle_low_byte;
unsigned char DesiredPWMDutyCycle_high_byte;
unsigned char CurrentPWMDutyCycle_low_byte;
unsigned char CurrentPWMDutyCycle_high_byte;
unsigned int digital_outl[8];
unsigned int digital_outh[8];
unsigned int i=0;
unsigned char data[20]=”ADC OUTPUT=”;
unsigned int avg_outputl=0;
unsigned int avg_outputh=0;
unsigned int templ;
unsigned int temph;
void main ( )
{
while(1)
{
/* ADC intinliazaione start */
TRISC=0; // MAKE PROT C OUTPUT
TRISB=0; // MAKE PORT B OUTPUT
TRISAbits.TRISA0=0; // Ra0 in for analog port
ADCON0 = 0x23; // cont. loop mode, auto conv,a/d on
ADCON1 = 0xDC; // an3 as vref+,buffer empty
ADCON2 = 0x89; // RIGHT justifed, 2Adc aquistion time, Fosx/32 used
ADCON3 = 0x10; // pwm triger
ADCHS = 0x00; //
ANSEL0 = 0xFF; // AN0-7 analog input
// ANSEL1 = 0x01; // analog input pin enable
PIR1bits.ADIF=0; // CLEAR A/D INTERRUPT FLAG
PIE1bits.ADIE=1; // enble a/d interrupt
INTCONbits.PEIE=1; // enable peripheral interupts
INTCONbits.GIE=1; // enable all interup globaly
/* ADC intinliazaione end */
/* pwm internalization start*/
PTCON0=0x00; // free runing mode, no pre post scalers
PTCON1=0x80; // up counting, time base on
PWMCON0=0x47; //all pwm 0 to 5 output, indepedent mode not complimentry
PWMCON1=0x03; // 1:1 postscare, o/p override snch on
// PTMRL=0x00;
// PTMRH=0x04;
_asm
MOVLW B’01100100′ ;
MOVWF PTPERL
_end
PTPERL= B’01100100′;//100;//0xFF; // Fpwm=2.4khz, Fosc=40Mhz, PTMRPS0.97
//PTPERH=100;//0x0F;
/* pwm intinliazaione end*/
/* start code*/
// PDC0L= MIN_DUTY_CYCLE;//25; //ADRESL; //current duty cyle
// PDC0H= MIN_DUTY_CYCLE;//25; //ADRESH; // current duty cyle
// PORTC=ADRESL;
PDC1L= 40; //urrent duty cyle
PDC1H= 40; // current duty cyle
PDC2L= 55; //cADRESL; //urrent duty cyle
PDC2H= 55; //ADRESH; // current duty cyle
OVDCOND=0xFF; // pwm control by duty cycle
// OVDCONS=0xDE; // PWM 0 & 5 ON
// msdelay(5);
// OVDCONS=0xDB; // PWM 2 & 5 ON
// msdelay(5);
// OVDCONS=0XF9; // PWM 2 & 1 ON
// msdelay(5);
// OVDCONS=0xED; // PWM 1 & 4 ON
// msdelay(5);
// OVDCONS=0XE7; // PWM 4 & 3 ON
// msdelay(5);
// OVDCONS=0xF6; // PWM 3 & 0 ON
// msdelay(5);
PTCON1bits.PTEN=1; // start pulse
PIR3bits.PTIF=0; //clear flag
while(PIR3bits.PTIF==0); //wait for period
msdelay(50);
PTCON1bits.PTEN=0x00;
}// while loop over
}// main loop over
//
A/D ISRvoid AD_ISR(void)
{
PORTC=ADRESL; // DISPLY LOW BYTE ON PORT C
templ=0;
temph=0;
for(i=0;i<8;i++)
{
// ADCON0|=(1<<GO); // Start A/D conversion
ADCON0bits.GO = 1; // START CONVERTING
while(ADCON0bits.DONE == 1); // Wait until conversion gets over
// digital_out
(ADRESL)|(ADRESH<<
); // Store 10-bit output into a 16-bit variabledigital_outl[8]=ADRESL;
digital_outh[8]=ADRESH;
msdelay(20);
templ=templ+digital_outl;
temph=temph+digital_outh;
}
avg_outputl=templ/8; // Take average of ten digital values for stablity
avg_outputh=temph/8;PDC0L= avg_outputl; //ADRESL; //current duty cyle
PDC0H= avg_outputh; //50; // current duty cyle
//
// PORTB=ADRESH; // DISTPLAY HIGH BYTE ON PORT D*/
msdelay(1); // WAIT
PIR1bits.ADIF=0; // CLEAR A/D INTERRUPT FLAG
}
void msdelay(unsigned int itime)
{
unsigned int i;
unsigned char j;
for ( i=0; i<itime;i++);
for(j=0;j<1; j++);
}
- You must be logged in to reply to this topic.