Help , pic16f877a mcu

[yyyyaser]

Help , pic16f877a , pwm for a motor

why is this code not working?

when set_point < feed_back , the if statement is executed.

but when set_point > feed_back , the it doesn't.

and it is working on the sw debugger but not on the breadboard.

//---------------------------------------------------------

unsigned int set_point , feed_back;
signed int current_duty;

void InitMain() {

PORTA = 0;
TRISA = 0xff; //PORT A FOR A/D CONVERSION

/*ADCON0 = 0x00000001; //PORT A WORKS AS AN ANALOG INPUT NOT DIGITAL */

PORTE = 0; // set PORTE to 0
TRISE = 0; // designate PORTE pins as output
PWM1_Init(20000); // Initialize PWM1 module at 20KHz

}

void main() {
InitMain();

ADC_Init();
PWM1_Start(); // start PWM1

while (1) {
set_point = ADC_Read(0);
feed_back = ADC_Read(1);

if(set_point<feed_back)
{
PORTE.B1=0;
PORTE.B2=1;
}

else if(set_point>=feed_back)

{
PORTE.B1=1;
PORTE.B2=0;
}

current_duty = set_point - feed_back;
current_duty = current_duty * (255.0/1023.0) ;
current_duty = abs( current_duty );

PWM1_Set_Duty(current_duty); // Set current duty for PWM1
}
}

 

[Zwilorg]

try to change from "else if" to just "if" ---- at least i don´t ever use the "else if" option because of that weird errors all over...

current_duty = abs( current_duty );

where do you have this routine working? it can come handy for me ^^

 

[yyyyaser]

try to change from "else if" to just "if" ---- at least i don´t ever use the "else if" option because of that weird errors all over...

current_duty = abs( current_duty );

where do you have this routine working? it can come handy for me ^^

well , I tried both if , else if , neither of them worked.

abs is is a standard library fn available in microC :] , returns the absolute value

 

[Zwilorg]

void InitMain() {

ADCON1=0x00;
TRISA = 0xff; //PORT A FOR A/D CONVERSION

/*ADCON0 = 0x00000001; //PORT A WORKS AS AN ANALOG INPUT NOT DIGITAL */

PORTE = 0; // set PORTE to 0
TRISE = 0; // designate PORTE pins as output
PWM1_Init(20000); // Initialize PWM1 module at 20KHz

}

I think you need to config the ADCON1 aswell :S

what a pitty that is on MikroC (abs fn) i use hi-tech C i have to search to see if i have any of those already built in the compiler ^^

 

[yyyyaser]

It finally worked ,I moved one output to a different port and it worked , but I don't understand why I can't use both pins on the same port .