 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.
+	//TODO: do some system checks, like battery level, connections etc.
+
+	// Start serial comms at the same baud rate as the engines.
+	Serial.begin(engine1.serialBaudRate);
 		
-	engine1.setPulseWidth(1100); // Arm the motor by setting the control at zero throttle position.
-	delay(25000);
+	// Arm the motors by setting the control at zero throttle position.
+	engine1.setPulseWidth(MOTOR_ARM_PULSE_WIDTH);
+	engine2.setPulseWidth(MOTOR_ARM_PULSE_WIDTH);
+	engine3.setPulseWidth(MOTOR_ARM_PULSE_WIDTH);
+	engine4.setPulseWidth(MOTOR_ARM_PULSE_WIDTH);
+	delay(25000); // Keep the throttle in zero position for a while to arm the motors.
 	Serial.println("Armed the motors.");
-
-//TODO: initialise all the sensors etc.
-	depthSensor = DepthSensor("depthReading",15);
+	
+	//TODO: do whatever else operations we want to do at start-up.
 	
 	Serial.println("ROV listening to commands."); //TODO: could add VERSION, ROVMODEL etc. consts somewhere so we know what ROV we're using.
 }

 * SENSOR DEFINITIONS.
 * =============================================================================
 */
// Commands that will be sent to the Arduino to request data from sensors.
const char* DEPTH_SENSOR_LABEL = "depthReading"; // Used to request data from the depth sensor.

DepthSensor depthSensor;

/* =============================================================================
 * TELECOMMAND PROTOCOL DEFINITION.

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, &depthSensor2};

/* =============================================================================
 * FUNCTIONS DEFINITIONS.
