test.py

import serial
import termios
import fcntl
from rplidar import RPLidar, RPLidarException

PORT_NAME = '/dev/ttyUSB0'
CUSTOM_BAUD = 256000

def set_custom_baud(serial_port, baud):
    """Set a custom baud rate on Linux using BOTHER"""
    fd = serial_port.fileno()
    attrs = termios.tcgetattr(fd)
    
    # BOTHER = 0x1000 (from asm-generic/termios.h)
    BOTHER = 0x1000
    
    # Input/output speeds
    attrs[4] = BOTHER  # ispeed
    attrs[5] = BOTHER  # ospeed
    
    # c_cflag holds the actual baud rate in c_ospeed/c_ispeed when BOTHER is set
    attrs[2] &= ~termios.CBAUD  # Clear old baud flags
    attrs[2] |= BOTHER
    
    # Set the file descriptor
    termios.tcsetattr(fd, termios.TCSANOW, attrs)
    
    # Use ioctl to set exact baud
    fcntl.ioctl(fd, termios.TIOCSSERIAL, baud)

# Open serial port manually
ser = serial.Serial(PORT_NAME, baudrate=115200, timeout=1, dsrdtr=True)
set_custom_baud(ser, CUSTOM_BAUD)

# Pass this serial object to RPLidar
lidar = RPLidar(PORT_NAME, baudrate=CUSTOM_BAUD)

try:
    info = lidar.get_info()
    print("Lidar info:", info)

    print("Scanning for 5 seconds...")
    import time
    start = time.time()
    for scan in lidar.iter_scans():
        for (_, angle, distance) in scan:
            print(f"Angle: {angle:.2f}, Distance: {distance} mm")
        if time.time() - start > 5:
            break

finally:
    lidar.stop()
    lidar.disconnect()
    ser.close()
    print("Lidar disconnected.")