 const char DATA_DELIMITER[2] = ","; // Splits the command name and value. For some reason has to be size 2.
 
 Module* actuators[] = {&engine1, &engine2, &engine3, &engine4};
-Module* sensors[] = {&depthSensor};
+Module* sensors[] = {&depthSensor, &depthSensor2};
 
 /* =============================================================================
  * FUNCTIONS DEFINITIONS.

void setup(void)
/* Prepare to listen to commands over serial and start everything up. */
{
//TODO: do some system checks, like battery level, connections etc.

//TODO: add more motors.
	engine1 = BrushlessDCMotor(ENGINE_LABEL_1, 100, 2200, 800, MOTOR_1_PIN, RELAY_1_PIN); // These pule widths correspond to the currently selected electronic speed controller (ESC) - Turningy EA-
	Serial.begin(engine1.serialBaudRate); // Start serial comms at the same baud rate as the engines.
		
	engine1.setPulseWidth(1100); // Arm the motor by setting the control at zero throttle position.
	delay(25000);
	Serial.println("Armed the motors.");

//TODO: initialise all the sensors etc.
	depthSensor = DepthSensor("depthReading",15);
	
	Serial.println("ROV listening to commands."); //TODO: could add VERSION, ROVMODEL etc. consts somewhere so we know what ROV we're using.
}

 * MOTOR DEFINITIONS.
 * =============================================================================
 */
// These values correspond to the currently selected electronic speed controller (ESC) - Turningy EA-25a.
#define MOTOR_ARM_PULSE_WIDTH 11000 // Pulse width in microseconds corresponding to zero throttle; used to arm the motors.
#define MOTOR_MAX_PULSE_WIDTH 2200 // Maximum pulse width of the motor in microseconds.
#define MOTOR_MIN_PULSE_WIDTH 800 // Minimum pulse width of the motor.
#define THROTTLE_STEPS 100 // How many levels of throttle we want to have.

// Pins are pairs of close-by pins with PWM and digital ones.
BrushlessDCMotor engine1 = BrushlessDCMotor("motorPortHor", THROTTLE_STEPS, MOTOR_MAX_PULSE_WIDTH, MOTOR_MIN_PULSE_WIDTH, 9, 8);
BrushlessDCMotor engine2 = BrushlessDCMotor("motorStbdHor", THROTTLE_STEPS, MOTOR_MAX_PULSE_WIDTH, MOTOR_MIN_PULSE_WIDTH, 6, 7);
BrushlessDCMotor engine3 = BrushlessDCMotor("motorPortVer", THROTTLE_STEPS, MOTOR_MAX_PULSE_WIDTH, MOTOR_MIN_PULSE_WIDTH, 5, 4);
BrushlessDCMotor engine4 = BrushlessDCMotor("motorStbdVer", THROTTLE_STEPS, MOTOR_MAX_PULSE_WIDTH, MOTOR_MIN_PULSE_WIDTH, 3, 2);

/* =============================================================================
 * MISC ACTUATOR DEFINITIONS.
