Code for a simple line follower using PIC18F4550

Open the Demo project in your MPLAB program. Type in the following code into the code window overwriting what is written before. Click build all (or press Ctrl + F-10).




/** I N C L U D E S **********************************************************/
#include
#include

/** V A R I A B L E S ********************************************************/
#pragma udata

/** P R I V A T E P R O T O T Y P E S ***************************************/

/** V E C T O R R E M A P P I N G *******************************************/

extern void _startup (void); // See c018i.c in your C18 compiler dir
#pragma code _RESET_INTERRUPT_VECTOR = 0x000800
void _reset (void)
{
_asm goto _startup _endasm
}
#pragma code

#pragma code _HIGH_INTERRUPT_VECTOR = 0x000808
void _high_ISR (void)
{
;
}

#pragma code _LOW_INTERRUPT_VECTOR = 0x000818
void _low_ISR (void)
{
;
}
#pragma code

/** D E C L A R A T I O N S **************************************************/
#pragma code
/******************************************************************************
* Function: void main(void)
*
* PreCondition: None
*
* Input: None
*
* Output: None
*
* Side Effects: None
*
* Overview: Main program entry point.
*
* Note: None
*****************************************************************************/
/** L E D ***********************************************************/


// Sensor Inputs
#define mInitAllSensors() TRISAbits.TRISA1=1;TRISAbits.TRISA2=1;
#define mInitAllLEDs() TRISBbits.TRISB0=0;TRISBbits.TRISB1=0;


#define SensorLeft PORTAbits.RA2
#define SensorRight PORTAbits.RA1


#define LeftLED PORTBbits.RB0
#define RightLED PORTBbits.RB1

int i=0;


void Delay_ms( long int x)
{
for(i=0;i
}
void Delay_s( long int x)
{
for(i=0;i}
void Delay_us(long int x)
{
for(i=0;i}

int sensor =0;



int SensorR()
{SetChanADC( ADC_CH1 );
ConvertADC(); // Start conversion
while( BusyADC() ); // Wait for completion
sensor = ReadADC(); // Read result
if (sensor<350) return 1;
if(sensor>350) return 0;
}

int SensorL()
{SetChanADC( ADC_CH2 );
ConvertADC(); // Start conversion
while( BusyADC() ); // Wait for completion
sensor = ReadADC(); // Read result
if (sensor<350) return 1;
if(sensor>350) return 0;
}






void code()
{

if(SensorL()==1 && SensorR()==0) {RightLED=1;LeftLED=0;}
else if (SensorR()==1 && SensorL()==0){LeftLED=1;RightLED=0;}
else {LeftLED=0;RightLED=0;}

}

void main(void)
{
ADCON1 |= 0x0F; // Default all pins to digital
mInitAllSensors();
mInitAllLEDs();




//ADC begins

OpenADC( ADC_FOSC_2 & ADC_RIGHT_JUST & ADC_1ANA , ADC_CH1 & ADC_INT_OFF & ADC_VREFPLUS_VDD & ADC_VREFMINUS_VSS , 0b1010 );
OpenADC( ADC_FOSC_2 & ADC_RIGHT_JUST & ADC_1ANA , ADC_CH2 & ADC_INT_OFF & ADC_VREFPLUS_VDD & ADC_VREFMINUS_VSS , 0b1010 );
Delay_ms( 50 ); // Delay for 50
//ADC ends


code();




}

//end main

/** EOF Demo02.c *************************************************************/