File content as of revision 0:63c4c959e87f:

#include "mbed.h"
#include "MODSERIAL.h" 


DigitalOut myled1(LED1);
DigitalOut myled2(LED2);
DigitalOut myled3(LED3);
DigitalOut myled4(LED4);


//motor a
PwmOut motFront(p21);
DigitalOut frontIN1(p24); 
DigitalOut frontIN2(p25);

//motor b
PwmOut motLeft(p22);
DigitalOut leftIN1(p27);
DigitalOut leftIN2(p26);

//motor c/d - motors are same in control just opposite direction so hardware can accomplish this
PwmOut motRight(p23);
DigitalOut rightIN1(p28);
DigitalOut rightIN2(p29);

//motor standby
DigitalOut motRLstby(p30);
DigitalOut motFstby(p20);

//xBee configurations
MODSERIAL pc(USBTX, USBRX); // tx, rx
MODSERIAL xbee(p13, p14); //tx, rx
//MODSERIAL bluetooth(p9, p10);
DigitalOut rstXbee(p15);

//motor globals
int rightMotor;
int leftMotor;

DigitalOut LEDlow(p19);
DigitalOut LEDmid(p18);
DigitalOut LEDhigh(p17);
DigitalOut LEDantenna(p16);

/*************************************************
function to receive packets from controller xbee
*************************************************/
void xbeeReceive()
{
    char packetFound = 0;
    char currentByte;
    if(xbee.rxBufferGetCount() == 0)
    {
        return;
    }
    while(xbee.rxBufferGetCount() >= 5)
    {
        currentByte = xbee.getc();
        if(currentByte == 0xAA)
        {
            currentByte = xbee.getc();
            if(currentByte == 0xBB)
            {
                //pc.printf("found the preamble");
                currentByte = xbee.getc();
                if(currentByte == 0x02)
                {
                    //pc.printf("found a packet");
                    packetFound = 1;
                    break;
                }
            }
        }
    }
    if(packetFound == 1)
    {
        //pc.printf("reading the packet");
        //read in the motor commands
        int rightTemp = xbee.getc();
        int leftTemp = xbee.getc();
        //calculate checksum
        char checkSumCalc = 0;
        checkSumCalc ^= rightTemp;
        checkSumCalc ^= leftTemp;
        char checkSumSent = xbee.getc();
        if(checkSumCalc == checkSumSent)
        {
            rightMotor = rightTemp;
            leftMotor = leftTemp;
        }
        else
        {
           // pc.printf("\n bad packet \n");
        }
    }
}

/*************************************************
main function
*************************************************/
int main() {
    //reset the xbee
    rstXbee = 0;
    wait_ms(1); 
    rstXbee=1;
    wait_ms(1);
   
   //led reset verification 
    myled1 = 1;
    wait(0.1);
    myled2 = 1;
    myled1 = 0;
    wait(0.1);
    myled2=0;
    
    //initialize motor stuff
    motRLstby=1;
    motFstby=1;
    motFront = motLeft = motRight=0;
    frontIN1 = 0;
    frontIN2 = 0;
    leftIN1 = 0;
    leftIN2 = 0;
    rightIN1 = 0;
    rightIN2 = 0;
    
    rightMotor = 0;
    leftMotor = 0;
    
    LEDlow=LEDmid=LEDhigh=LEDantenna=0;

    while(1) {
        
      //  bluetooth.putc('q');
        
        
        xbeeReceive(); //read data from xbee
      //  printf("right: %d    ", rightMotor);
      //  printf("left: %d    \r\n", leftMotor);
        
        //rightMotor=rightMotor-8;
        //motor control
        
        //right motor
        if(rightMotor <= 135 && rightMotor >= 128)
        {
            //turn off motor
            motRight = 0.0;

        }
        else if(rightMotor > 135)
        {
            //right motor forward
             rightIN1=1;
             rightIN2=0;
             motRight = (((float)rightMotor-135.0)/120.0);
        }
        else if(rightMotor < 128)
        {
            //right motor backwards
            rightIN1=0;
            rightIN2=1;
            motRight = ((255.0-(float)rightMotor)/255.0);
        }
         //left motor
        if(leftMotor <= 142 && leftMotor >= 136)
        {
            //turn off motor
            motLeft = 0.0;

        }
        
        else if(leftMotor > 142)
        {
            //left motor forward
             leftIN1=0;
             leftIN2=1;
             motLeft = (((float)leftMotor-142.0)/113.0);
        }
        else if(leftMotor < 136)
        {
            //left motor backwards
            leftIN1=1;
            leftIN2=0;
            motLeft = ((255.0-(float)leftMotor)/255.0);
        }
        //front and back motors
        if(rightMotor < 15 && leftMotor > 240) //only kick in if there is a large different in directions of motors
        {
            //rotate clockwise
             motFstby=1;
            frontIN1 = 1;
            frontIN2 = 0;
            motFront = 1;
            LEDantenna=LEDlow=LEDmid=LEDhigh=1;
           // printf("
            
            
        }
        else if(leftMotor < 15 && rightMotor > 240)
        {
            //rotate counter-clockwise
            motFstby=1;
             frontIN1 = 0;
            frontIN2 = 1;
            motFront = 1;
            LEDantenna=LEDlow=LEDmid=LEDhigh=1;
        } 
        else
        {
            motFront=0;
            motFstby = 0;
            LEDantenna=LEDlow=LEDmid=LEDhigh=0;
        }
        
        
    }
}