VE and L298P motor shield

Hello,

We are trying to do a fish on wheels build as a school project. Like this: http://www.youtube.com/watch?v=YbNmL6hSNKw
We use this http://www.dfrobot.com/wiki/index.php/Cherokey_4WD_Mobile_Platform_%28SKU:ROB0102%29 as our platform, and an arduino UNO together with the Video Experimenter Shield.

We get the VE shield to work just fine at tracking our fish/laser pointer.
We have stacked the VE shield on the UNO, and connected the pin outs from the Cherokey to pins 3,5,10 and 11 on the VE.
The Cherokey works when we only run code for the motors, but as soon as we tried to put together the code for the VE and the motors we ran into a problem. The VE is still working as intended. We get proper tracking, and also image on our monitor, but we only get one of the two motors on the cherokey to run.

This is a stripped down version of the code we are using to troubleshoot:

//DEFINISJONER FOR VIDEO SHIELD

#include 

#include 

#define W 128

#define H 96



//INITIALISERINGER FOR VIDEO SHIELD

TVout tv;

unsigned char x,y;

unsigned char c;

unsigned char minX,minY,maxX,maxY;

char s[32];





//INITIALISERINGER FOR MOTORKONTROLL



int E1 = 5;     //M1 Speed Control

int E2 = 10;     //M2 Speed Control

int M1 = 3;     //M1 Direction Control

int M2 = 11;     //M2 Direction Control



void setup()

{

tv.begin(PAL, W, H);

initOverlay();

initInputProcessing();



tv.select_font(font4x6);

tv.fill(0);

}



void initOverlay() {

TCCR1A = 0;

// Enable timer1.  ICES0 is set to 0 for falling edge detection on input capture pin.

TCCR1B = _BV(CS10);



// Enable input capture interrupt

TIMSK1 |= _BV(ICIE1);



// Enable external interrupt INT0 on pin 2 with falling edge.

EIMSK = _BV(INT0);

EICRA = _BV(ISC11);

}



void initInputProcessing() {

// Analog Comparator setup

ADCSRA &= ~_BV(ADEN); // disable ADC

ADCSRB |= _BV(ACME); // enable ADC multiplexer

ADMUX &= ~_BV(MUX0);  // select A2 for use as AIN1 (negative voltage of comparator)

ADMUX |= _BV(MUX1);

ADMUX &= ~_BV(MUX2);

ACSR &= ~_BV(ACIE);  // disable analog comparator interrupts

ACSR &= ~_BV(ACIC);  // disable analog comparator input capture

}



// Required

ISR(INT0_vect) {

display.scanLine = 0;

}



//MOTOR CONTROL FUNCTIONS



//FORWARD

void advance(char a,char b)

{

analogWrite (E1,a);      //PWM Speed Control

digitalWrite(M1,HIGH);

analogWrite (E2,b);

digitalWrite(M2,HIGH);

}





void loop(void)

{

advance (100,100);

tv.capture();



// uncomment if tracking dark objects

//tv.fill(INVERT);



//LOGIKK FOR Å BEREGNE "BOUNDING BOX" RUNDT OBJEKT

minX = W;

minY = H;

maxX = 0;

maxY = 0;

boolean found = 0;

for(int y=5;y<80;y++) {

for(int x=10;x<110;x++) {

c = tv.get_pixel(x,y);

if (c == 1) {

found = true;

if (x < minX) {

minX = x;

}

if (x > maxX) {

maxX = x;

}

if (y < minY) {

minY = y;

}

if (y > maxY) {

maxY = y;

}

}

}

}



//TEGNER BOUNDING BOX TIL MONITOR

tv.fill(0);

if (found) {

tv.draw_line(minX, minY, maxX, minY, 1);

tv.draw_line(minX, minY, minX, maxY, 1);

tv.draw_line(maxX, minY, maxX, maxY, 1);

tv.draw_line(minX, maxY, maxX, maxY, 1);

sprintf(s, "%d, %d", ((maxX+minX)/2), ((maxY+minY)/2));

tv.print(0, 0, s);

}



tv.resume();

tv.delay_frame(2);

/*Serial.begin(9600);

Serial.print(xVektor);

Serial.print('t');

Serial.print(yVektor);

Serial.print('n');*/





}//SLUTT PÅ HOVEDLØKKE

There seem to be some sort of conflict, but we have no idea what it can be. We are kinda lost, and hope someone on here can give us some help!