Globals and Utils

The globals and utils modules, containing shared global variables and utility functions, play a crucial role in the Lidar Distance system.

Global Variables (globals.py)

Variables

• stop_front: Flag indicating whether there is an obstacle in the front.
• stop_right: Flag indicating whether there is an obstacle on the right.
• stop_left: Flag indicating whether there is an obstacle on the left.
• stop_front_right: Flag indicating whether there is an obstacle in the front-right.
• stop_front_left: Flag indicating whether there is an obstacle in the front-left.
• stop_threads: Flag indicating whether all threads should stop.
• minDist: The minimum distance considered for obstacle detection.
• maxLenBuffer: The maximum length of the Lidar data buffer.

Usage

These global variables are used across different threads to manage the system’s state and obstacle detection.

Utility Functions (utils.py)

Functions

connect_to_server(ip_address, server_port)

Creates a TCP/IP socket and connects to the server.

• Parameters:
  • ip_address: IP address of the server.
  • server_port: Port number of the server.
• Returns: A connected socket.

pregenerate_lidar_data(maxlen)

Generates a Lidar data buffer with a specified maximum length.

• Parameters:
  • maxlen: Maximum length of the Lidar data buffer.
• Returns: A deque object representing the Lidar data buffer.

signal_handler(sig, frame)

Handles the Ctrl+C signal and exits the program gracefully.

• Parameters:
  • sig: Signal number.
  • frame: Current stack frame.
• Usage: This function is used as a signal handler for Ctrl+C interruptions.

Script Execution

Globals and utils are imported and utilized in various modules and threads across the Lidar Distance system.

from globals import stop_front, stop_right, stop_left, stop_front_right, stop_front_left, stop_threads, minDist, maxLenBuffer
from utils import connect_to_server, pregenerate_lidar_data, signal_handler