 // Function to drive a specific motor backwards. 
 // Packet format: Address Byte, Command Byte, Value Byte, Checksum.
 void driveBackwards(char speed, char motor){
-  unsigned char address = DRIVE_MOTOR_ADDRESS[motor];
-  unsigned char command = DRIVE_MOTOR_COMMAND[motor] + 1;
+  unsigned char address = MOTOR_ADDRESS[motor];
+  unsigned char command = MOTOR_COMMAND[motor] + 1;
   unsigned char checksum = (address + command + speed) & 0b01111111;
   Serial3.write(address);
   Serial3.write(command);

const unsigned char MIDDLE_RIGHT_DRIVE_MOTOR_ID = 3;
const unsigned char REAR_LEFT_DRIVE_MOTOR_ID = 4;
const unsigned char REAR_RIGHT_DRIVE_MOTOR_ID = 5;

// Motor addressing (used to link the computer-constants to
// commands sent to the saberteeth).

const unsigned char MIDDLE_RIGHT_DRIVE_MOTOR_COMMAND = 0;
const unsigned char REAR_LEFT_DRIVE_MOTOR_COMMAND = 0;
const unsigned char REAR_RIGHT_DRIVE_MOTOR_COMMAND = 4;
// Articulation motor offsets. 0 or 4 corresponds to "counterclockwise".
// a value of 1 or 5 corresponds to "clockwise".
const unsigned char FRONT_LEFT_ARTICULATION_MOTOR_COMMAND = 0;
const unsigned char FRONT_RIGHT_ARTICULATION_MOTOR_COMMAND = 0;
const unsigned char MIDDLE_LEFT_ARTICULATION_MOTOR_COMMAND = 0;
const unsigned char MIDDLE_RIGHT_ARTICULATION_MOTOR_COMMAND = 0;
const unsigned char REAR_LEFT_ARTICULATION_MOTOR_COMMAND = 0;
const unsigned char REAR_RIGHT_ARTICULATION_MOTOR_COMMAND = 0;

// shorthand that will allow us to use the motor ID as an array index to access
// the relevant constants.
const unsigned char MOTOR_ADDRESS[12] = {
  FRONT_LEFT_DRIVE_MOTOR_ADDRESS,
  FRONT_RIGHT_DRIVE_MOTOR_ADDRESS,
  MIDDLE_LEFT_DRIVE_MOTOR_ADDRESS,
  MIDDLE_RIGHT_DRIVE_MOTOR_ADDRESS,
  REAR_LEFT_DRIVE_MOTOR_ADDRESS,
  REAR_RIGHT_DRIVE_MOTOR_ADDRESS,
  FRONT_LEFT_ARTICULATION_MOTOR_ADDRESS,
  FRONT_RIGHT_ARTICULATION_MOTOR_ADDRESS,
  MIDDLE_LEFT_ARTICULATION_MOTOR_ADDRESS,
  MIDDLE_RIGHT_ARTICULATION_MOTOR_ADDRESS,
  REAR_LEFT_ARTICULATION_MOTOR_ADDRESS,
  REAR_RIGHT_ARTICULATION_MOTOR_ADDRESS};
const unsigned char MOTOR_COMMAND[12] = {
  FRONT_LEFT_DRIVE_MOTOR_COMMAND,
  FRONT_RIGHT_DRIVE_MOTOR_COMMAND,
  MIDDLE_LEFT_DRIVE_MOTOR_COMMAND,
  MIDDLE_RIGHT_DRIVE_MOTOR_COMMAND,
  REAR_LEFT_DRIVE_MOTOR_COMMAND,
  REAR_RIGHT_DRIVE_MOTOR_COMMAND,
  FRONT_LEFT_ARTICULATION_MOTOR_COMMAND,
  FRONT_RIGHT_ARTICULATION_MOTOR_COMMAND,
  MIDDLE_LEFT_ARTICULATION_MOTOR_COMMAND,
  MIDDLE_RIGHT_ARTICULATION_MOTOR_COMMAND,
  REAR_LEFT_ARTICULATION_MOTOR_COMMAND,
  REAR_RIGHT_ARTICULATION_MOTOR_COMMAND};
  
  
// Track current motor status so we don't overload our serial lines
