sys.stdin.buffer # incoming bytes
sys.stdout.buffer # outgoing bytes

import sys
import select
import time

# Poll stdin without blocking
poll = select.poll()
poll.register(sys.stdin, select.POLLIN)

def handle_command(cmd_bytes):
    """
    Replace this function with logic ported
    from your Arduino C code.
    cmd_bytes is a bytes object.
    """
    # Example fixed reply (replace!)
    return b'\xFF\xFF\x01\x02\x00\xFC'

while True:
    if poll.poll(0):
        # Read available data
        data = sys.stdin.buffer.read(64)
        if data:
            response = handle_command(data)

            if response:
                sys.stdout.buffer.write(response)
                sys.stdout.buffer.flush()

    time.sleep_ms(1)

if (cmd == 0x01) {
    reply[0] = 0xFF;
    reply[1] = 0x00;
}

if cmd == 0x01:
    reply = b'\xFF\x00'

def handle_command(data):
    if data.startswith(b'\x01\x02'):
        return b'\xAA\xBB\xCC'
    elif data.startswith(b'\x10'):
        return b'\x10\x00'
    return None

for b in response:
    sys.stdout.buffer.write(bytes([b]))
    sys.stdout.buffer.flush()
    time.sleep_us(1040)  # ~9600 baud

import sys
import select
import time

poll = select.poll()
poll.register(sys.stdin, select.POLLIN)

def handle_command(data):
    # TODO: port Arduino C logic here
    return b'\xFF\xFF\x01\x02\x00\xFC'

while True:
    if poll.poll(0):
        data = sys.stdin.buffer.read(64)
        if data:
            response = handle_command(data)
            if response:
                sys.stdout.buffer.write(response)
                sys.stdout.buffer.flush()
    time.sleep_ms(1)