/*! send robot speed
\return  0 no error occured
					-1 left i2c error occured
					-2 right i2c error occured
					-3 left and right motor i2c error	
*/ 
int stop_drive_motors() {

	set_drive_motors_mode(eCTRL_SPEED_ACC,eCTRL_SPEED_ACC);
	set_drive_speed(0,0);
	usleep(500000);
	return set_drive_motors_mode(eCTRL_IDLE,eCTRL_IDLE);
}