init

main.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+
+import socket
+import struct
+import sys
+import libevdev
+#from libevdev import ecodes
+
+def main(device_path, dest_ip, dest_port,username,password):
+    """
+    Reads absolute X and Y coordinates from an evdev device and sends them
+    over UDP to a specified address and port.
+
+    Args:
+        device_path (str): The path to the input event device 
+                           (e.g., /dev/input/event0).
+        dest_ip (str): The destination IP address.
+        dest_port (int): The destination port.
+    """
+    try:
+        # Open the evdev device in a non-blocking way
+        fd = open(device_path, 'rb')
+        d = libevdev.Device(fd)
+        print(f"Successfully opened device: {d.name}")
+
+
+        print("Listening for ABS_X and ABS_Y events. Press Ctrl+C to exit.")
+
+        # Create a UDP socket
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        print(f"Sending coordinates to {dest_ip}:{dest_port}")
+
+        # Variables to store the latest coordinates
+        x_coor = None
+        y_coor = None
+
+        # Loop indefinitely to read events
+        while True:
+            for e in d.events():
+                # We are only interested in absolute axis events
+                if e.type == libevdev.EV_ABS:
+                    if e.code == libevdev.EV_ABS.ABS_X:
+                        x_coor = e.value
+                    elif e.code == libevdev.EV_ABS.ABS_Y:
+                        y_coor = e.value
+
+                # When we have both coordinates, send them
+                if x_coor is not None and y_coor is not None:
+                    print(f"Read coordinates: X={x_coor}, Y={y_coor}")
+                    
+                    # Pack the two 16-bit unsigned integers into a buffer.
+                    # The format string 'HH' specifies two unsigned short integers (u16).
+                    # The '<' character ensures little-endian byte order.
+                    try:
+                        packet = struct.pack('<HH', x_coor, y_coor)
+                        
+                        # Send the packet over UDP
+                        sock.sendto(packet, (dest_ip, dest_port))
+                        print(f"Sent {len(packet)} bytes.")
+
+                        # Reset coordinates to wait for the next pair of events
+                        x_coor = None
+                        y_coor = None
+
+                    except struct.error as se:
+                        print(f"Error packing data: {se}. Coordinates might be out of range for u16 (0-65535).")
+                    except socket.error as soe:
+                        print(f"Socket error: {soe}")
+
+
+    except FileNotFoundError:
+        print(f"Error: Device not found at {device_path}")
+        print("Please ensure you have the correct event device path.")
+    except PermissionError:
+        print(f"Error: Permission denied for {device_path}.")
+        print("This script usually needs to be run with root privileges (e.g., 'sudo python3 script.py')")
+    except KeyboardInterrupt:
+        print("\nExiting.")
+    finally:
+        if 'fd' in locals() and not fd.closed:
+            fd.close()
+        if 'sock' in locals():
+            sock.close()
+
+if __name__ == "__main__":
+    if len(sys.argv) != 4:
+        print("Usage: python3 evdev_udp_sender.py <device_path> <dest_ip> <dest_port>")
+        print("Example: sudo python3 evdev_udp_sender.py /dev/input/event4 127.0.0.1 12345")
+        sys.exit(1)
+
+    device = sys.argv[1]
+    ip = sys.argv[2]
+    try:
+        port = int(sys.argv[3])
+        if not (0 < port < 65536):
+            raise ValueError
+    except ValueError:
+        print("Error: Port must be an integer between 1 and 65535.")
+        sys.exit(1)
+        
+    main(device, ip, port)
+

shell.nix

@@ -0,0 +1,13 @@
+let
+  pkgs = import <nixpkgs> {};
+in pkgs.mkShell {
+  packages = [ pkgs.libinput
+    (pkgs.python3.withPackages (python-pkgs: [
+python-pkgs.paho-mqtt
+pkgs.libinput
+python-pkgs.libevdev
+    ]))
+  ];
+}
+
+