struct room {
	int id;
	char* name;
	struct wall* walls;
	int cost;
};

struct wall {
	double long1, lat1;
	double long2, lat2;
	int cost;
	struct room* portal;			// NULL if it is a wall
	struct wall* nextwall;			// NULL if this is the last wall
};

struct disk_room {
	int id;
	char name[256];
	int cost;
	int count;				// count of walls
	// FOLLOWING THIS, we write out count walls to the file, and read in that many walls for this room.
};

struct disk_wall {
	double long1, lat1;
	double long2, lat2;
	int portal;				// Link to the disk_room->id: -1 if this is NOT a portal, but JUST A wall.
	int cost;
};0

void servo_turn(int direction);			// range: -127 <-> +127 where -127 is full left, and 127 is full right
void servo_speed(int speed);			// range: -127 <-> +127 where -127 is full reverse, and 127 is full forward
void servo_update();				// update PWM - needs to be called at 50hz. apparently 1ms->2ms wide pulses

void steering_check();				// check to make sure that we are steering in the right direction

void speed_check();				// check to make sure that speed is appropriate (ie, don't tip over during turns, etc)