 // ROS cmd_vel subscriber
 // Threshold, in seconds, to wait for a cmd_vel message else take action
 // to stop robot activity
-#define CMD_VEL_TIMEOUT_THRESHOLD 0.2 // 200 milliseconds
+const double CMD_VEL_TIMEOUT_THRESHOLD(0.2); // 200 milliseconds
 ros::Time last_cmd_vel_time;
 bool cmd_vel_timeout_stop = false; // Set to true if time out threshold has been exceeded
 void cmdVelCallback(const geometry_msgs::Twist& twist_msg);

double motor_right_speed;

// Victoria constants
#define TICKS_PER_RADIAN 9072 // TODO(mwomack): Verify real value
#define TRACK_RADIUS 0.235  // in meters
#define WHEEL_RADIUS 0.127  // in meters
#define MAX_SPEED 4.71      // in meters/second

// Bumper sensors
bool bumper_stop = false; // Set to true if bumpers indicate robot should stop

  ros_nh.subscribe(ros_cmd_vel_sub);

  // Setup Timer callbacks
  timer.every(convertFreqToMillis(read_encoders_freq_hz), doReadEncoders);
  timer.every(convertFreqToMillis(publish_odom_freq_hz), doPublishOdom);
  timer.every(convertFreqToMillis(publish_imu_freq_hz), doPublishImu);
  timer.every(convertFreqToMillis(publish_magnetometer_freq_hz), doPublishMagnetometer);
  timer.every(BLINK_DURATION, doBlink);

  ros::Time current_time = ros_nh.now();
