HW-VX6330K via RS232 atau TCP IP dengan Komputer §

from abc import ABC, abstractmethod
from socket import socket, AF_INET, SOCK_STREAM
from typing import TypeVar
import serial
 
T = TypeVar('T', bound='Parent')
 
 
class Transport(ABC):
    @abstractmethod
    def read_bytes(self, length: int) -> bytes:
        raise NotImplementedError
 
    @abstractmethod
    def write_bytes(self, buffer: bytes) -> None:
        raise NotImplementedError
 
    def read_frame(self) -> bytes | None:
        length_bytes = self.read_bytes(1)
        if not length_bytes:
            return
        frame_length = ord(chr(length_bytes[0]))
        data = length_bytes + self.read_bytes(frame_length)
        return bytearray(data)
 
    @abstractmethod
    def close(self) -> None:
        raise NotImplementedError
 
 
class TcpTransport(Transport):
    def __init__(self, ip_address: str, port: int, timeout: int = 1) -> None:
        self.socket = socket(AF_INET, SOCK_STREAM)
        self.socket.settimeout(timeout)
        self.socket.connect((ip_address, port))
 
    def read_bytes(self, length: int) -> bytes:
        return self.socket.recv(length)
 
    def write_bytes(self, buffer: bytes) -> None:
        self.socket.sendall(buffer)
 
    def close(self) -> None:
        self.socket.close()
 
 
class SerialTransport(Transport):
    def __init__(self, serial_port: str, baud_rate: int, timeout: int = 1) -> None:
        self.serial = serial.Serial(serial_port, baud_rate,
                                    timeout=timeout, write_timeout=timeout)
 
    def read_bytes(self, length: int) -> bytes:
        return self.serial.read(length)
 
    def write_bytes(self, buffer: bytes) -> None:
        self.serial.write(buffer)
 
    def close(self) -> None:
        self.serial.close()

from utils import calculate_checksum
 
CMD_INVENTORY: int = 0x01
CMD_READ_MEMORY: int = 0x02
CMD_WRITE_MEMORY: int = 0x03
CMD_SET_LOCK: int = 0x06
CMD_SET_READER_POWER: int = 0x2F
CMD_GET_WORK_MODE: int = 0x36
CMD_SET_WORK_MODE: int = 0x35
 
 
class Command:
    def __init__(self, command: int, reader_address: int = 0xFF,
                 data: bytes | int | None = None):
        self.command = command
        self.reader_address = reader_address
        self.data = data
        if isinstance(data, int):
            self.data = bytearray([data])
        if data is None:
            self.data = bytearray()
        self.frame_length = 4 + len(self.data)
        self.base_data = bytearray([self.frame_length, self.reader_address, self.command])
        self.base_data.extend(self.data)
 
    def serialize(self) -> bytes:
        serialize = self.base_data
        checksum = calculate_checksum(serialize)
        serialize.extend(checksum)
        return serialize

from dataclasses import dataclass
from enum import Enum
 
from utils import calculate_checksum, hex_readable
 
 
class Response:
    def __init__(self, response_bytes: bytes):
        if len(response_bytes) < 6:
            raise ValueError("Response data is too short to be valid.")
 
        self.response_bytes = response_bytes
        self.length = response_bytes[0]
 
        if len(response_bytes) < self.length:
            raise ValueError("Response length mismatch.")
 
        self.reader_address = response_bytes[1]
        self.command = response_bytes[2]
        self.status = response_bytes[3]  # Check 5. LIST OF COMMAND EXECUTION RESULT STATUS
        self.data = response_bytes[4: self.length - 1]
        self.checksum = response_bytes[self.length - 1: self.length + 1]
 
        # Verify checksum
        data = bytearray(self.response_bytes[0:4])
        data.extend(self.data)
        crc_msb, crc_lsb = calculate_checksum(data)
        assert self.checksum[0] == crc_msb and self.checksum[1] == crc_lsb
 
    def __str__(self) -> str:
        lines = [
            ">>> START RESPONSE ================================",
            f"RESPONSE       >> {hex_readable(self.response_bytes)}",
            f"READER ADDRESS >> {hex_readable(self.reader_address)}",
            f"COMMAND        >> {hex_readable(self.command)}",
            f"STATUS         >> {hex_readable(self.status)}",
        ]
 
        if self.data:
            lines.append(f"DATA           >> {hex_readable(self.data)}")
 
        lines.append(f"CHECKSUM       >> {hex_readable(self.checksum)}")
        lines.append(">>> END RESPONSE   ================================")
 
        return "\n".join(lines)
 
 
 
class InventoryWorkMode(Enum):
    ANSWER_MODE: int = 0
    ACTIVE_MODE: int = 1
    TRIGGER_MODE_LOW: int = 2
    TRIGGER_MODE_HIGH: int = 3
 
 
class OutputInterface(Enum):
    WIEGAND: int = 0
    RS232_485: int = 1
    SYRIS485: int = 2
 
 
class Protocol(Enum):
    PROTOCOL_18000_6C: int = 0
    PROTOCOL_18000_6B: int = 1
 
 
class AddressType(Enum):
    WORD: int = 0
    BYTE: int = 1
 
 
class WiegandOutputAddressing(Enum):
    WORD: int = 0
    BYTE: int = 1
 
 
class WiegandFormat(Enum):
    WIEGAND_26BITS: int = 0
    WIEGAND_34BITS: int = 1
 
 
class WiegandBitOrder(Enum):
    HIGH_BIT_FIRST: int = 0
    LOW_BIT_FIRST: int = 1
 
 
class WiegandMode:
    def __init__(self, value: int):
        self.value: int = value
 
        self._wiegand_format: WiegandFormat = WiegandFormat(value & 0b1)
        self._bit_order: WiegandBitOrder = WiegandBitOrder((value & 0b10) >> 1)
 
    def __str__(self) -> str:
        return (f"Wiegand Mode: {self.wiegand_format.name.replace('_', ' ')}, "
                f"Bit Order: {self.bit_order.name.replace('_', ' ')}")
 
    @property
    def wiegand_format(self) -> WiegandFormat:
        return self._wiegand_format
 
    @wiegand_format.setter
    def wiegand_format(self, fmt: WiegandFormat):
        self._wiegand_format = fmt
        self.update_value()
 
    @property
    def bit_order(self) -> WiegandBitOrder:
        return self._bit_order
 
    @bit_order.setter
    def bit_order(self, order: WiegandBitOrder):
        self._bit_order = order
        self.update_value()
 
    def update_value(self):
        self.value = (self._wiegand_format.value & 0b1) | ((self._bit_order.value & 0b1) << 1)
 
 
class WorkModeState:
    def __init__(self, value: int):
        self.value: int = value
 
        self.protocol: Protocol = Protocol(value & 0b1)
        self.output_interface: OutputInterface = OutputInterface((value & 0b10) >> 1)
        self.beep: bool = not bool(value & 0b100)
        self.address_type: AddressType = AddressType(value & 0b1000)
        self.rs485_enable: bool = bool(value & 0b10000)
 
    def __str__(self) -> str:
        return (f"Protocol: {self.protocol.name.replace('_', '-')} "
                f"| Output Mode: {self.output_interface.name.replace('_', '/')} "
                f"| Address Type: {self.address_type} | RS485: {'Enabled' if self.rs485_enable else 'Disabled'} "
                f"| Beep/Buzzer: {'Enabled' if self.beep else 'Disabled'}")
 
    def to_int(self) -> int:
        value = 0
        value |= self.protocol.value  # Bit 0
        value |= (self.output_interface.value << 1)  # Bit 1
        value |= (0 if self.beep else 0b100)  # Bit 2
        value |= (self.address_type.value << 3)  # Bit 3
        value |= (self.rs485_enable << 4)  # Bit 4
        return value
 
 
class InventoryMemoryBank(Enum):
    PASSWORD: int = 0
    EPC: int = 1
    TID: int = 2
    USER: int = 3
    INVENTORY_MULTIPLE: int = 4
    INVENTORY_SINGLE: int = 5
    EAS_ALARM: int = 6
 
 
class WorkMode:
    def __init__(self, response_bytes: bytes):
        self.wiegand_mode = WiegandMode(response_bytes[0])
        self.wiegand_interval = response_bytes[1]
        self.wiegand_pulse_width = response_bytes[2]
        self.wiegand_pulse_interval = response_bytes[3]
        self.inventory_work_mode = InventoryWorkMode(response_bytes[4])
        self.work_mode_state = WorkModeState(response_bytes[5])
        self.memory_bank = InventoryMemoryBank(response_bytes[6])
        self.first_address = response_bytes[7]
        self.word_number = response_bytes[8]
        self.single_tag_time = response_bytes[9]
        self.accuracy = response_bytes[10]
        self.offset_time = response_bytes[11]
 
    def __str__(self) -> str:
        return "\n".join([
            f"Wiegand Mode: {self.wiegand_mode}",
            f"Wiegand Interval: {self.wiegand_interval}",
            f"Wiegand Pulse Width: {self.wiegand_pulse_width}",
            f"Wiegand Pulse Interval: {self.wiegand_pulse_interval}",
            f"Inventory Work Mode: {self.inventory_work_mode.name.replace('_', ' ')}",
            f"Work Mode State: {self.work_mode_state}",
            f"Memory Bank: {self.memory_bank.name.replace('_', ' ')}",
            f"First Address: {self.first_address}",
            f"Word Number: {self.word_number}",
            f"Single Tag Time: {self.single_tag_time}",
            f"Accuracy: {self.accuracy}",
            f"Offset Time: {self.offset_time}"
        ])
 
    def to_bytes(self) -> bytes:
        return bytes([
            self.inventory_work_mode.value,
            self.work_mode_state.to_int(),
            self.memory_bank.value,
            self.first_address,
            self.word_number,
            self.single_tag_time,
        ])

from typing import Iterator
from transport import Transport
from command import *
from response import *
 
 
class Reader:
    def __init__(self, transport: Transport) -> None:
        self.transport = transport
 
    def close(self) -> None:
        self.transport.close()
 
    def __send_request(self, command: Command) -> None:
        self.transport.write_bytes(command.serialize())
 
    def __get_response(self) -> bytes:
        return self.transport.read_frame()
 
    def inventory_answer_mode(self,
                              start_address_tid: int | None = None,
                              len_tid: int | None = None,
                              ) -> Iterator[bytes]:  # 8.2.1 Inventory (Answer Mode)
        if start_address_tid is not None and len_tid is not None:
            command: Command = Command(CMD_INVENTORY, data=[start_address_tid, len_tid])
        else:
            command: Command = Command(CMD_INVENTORY)
        self.__send_request(command)
 
        response: Response = Response(self.__get_response())
        data: bytes = response.data
 
        if not data:
            return iter(())
 
        tag_count: int = data[0]
 
        n: int = 0
        pointer: int = 1
        while n < tag_count:
            tag_len = int(data[pointer])
            tag_data_start = pointer + 1
            tag_main_start = tag_data_start
            tag_main_end = tag_main_start + tag_len
            next_tag_start = tag_main_end
            tag = data[tag_data_start:tag_main_start] \
                  + data[tag_main_start:tag_main_end] + data[tag_main_end:next_tag_start]
            yield tag
            pointer = next_tag_start
            n += 1
 
    def inventory_active_mode(self) -> Iterator[Response]:
        while True:
            try:
                raw_response: bytes | None = self.__get_response()
            except TimeoutError:
                continue
            if raw_response is None:
                continue
            response: Response = Response(raw_response)
            yield response
 
    def read_memory(self, epc: bytes, memory_bank: int, start_address: int, length: int,
                    access_password: bytes = bytes(4)) -> Response:  # 8.2.2 Read Data
        request_data = bytearray()
        request_data.extend(bytearray([int(len(epc) / 2)]))  # EPC Length in word
        request_data.extend(epc)
        request_data.extend(bytearray([memory_bank, start_address, length]))
        request_data.extend(access_password)
        command: Command = Command(CMD_READ_MEMORY, data=request_data)
        self.__send_request(command)
 
        return Response(self.__get_response())
 
    def write_memory(self, epc: bytes, memory_bank: int, start_address: int,
                     data_to_write: bytes,
                     access_password: bytes = bytes(4)) -> Response:  # 8.2.4 Write Data
        request_data: bytearray = bytearray()
        request_data.extend(bytearray([int(len(data_to_write) / 2)]))  # Data length in word
        request_data.extend(bytearray([int(len(epc) / 2)]))  # EPC Length in word
        request_data.extend(epc)
        request_data.extend(bytearray([memory_bank, start_address]))
        request_data.extend(data_to_write)
        request_data.extend(access_password)
        command: Command = Command(CMD_WRITE_MEMORY, data=request_data)
        self.__send_request(command)
 
        return Response(self.__get_response())
 
    def lock(self, epc: bytes, select: int, set_protect: int, access_password: bytes) -> Response:  # 8.2.6 Lock
        parameter: bytearray = bytearray([int(len(epc) / 2)]) + epc + \
                               bytearray([select, set_protect]) + access_password
 
        command: Command = Command(CMD_SET_LOCK, data=parameter)
        self.__send_request(command)
 
        return Response(self.__get_response())
 
    def set_power(self, power: int) -> Response:  # 8.4.6 Set Power
        assert 0 <= power <= 30
 
        command: Command = Command(CMD_SET_READER_POWER, data=bytearray([power]))
        self.__send_request(command)
 
        return Response(self.__get_response())
 
    def work_mode(self) -> WorkMode:  # 8.4.10 Get WorkMode
        command: Command = Command(CMD_GET_WORK_MODE)
        self.__send_request(command)
 
        return WorkMode(Response(self.__get_response()).data)
 
    def set_work_mode(self, work_mode: WorkMode) -> Response:  # 8.4.9 Set WorkMode
        command: Command = Command(CMD_SET_WORK_MODE, data=work_mode.to_bytes())
        self.__send_request(command)
 
        return Response(self.__get_response())

def calculate_checksum(data: bytes) -> bytearray:
    value = 0xFFFF
    for d in data:
        value ^= d
        for _ in range(8):
            value = (value >> 1) ^ 0x8408 if value & 0x0001 else (value >> 1)
    crc_msb = value >> 0x08
    crc_lsb = value & 0xFF
    return bytearray([crc_lsb, crc_msb])
 
 
def hex_readable(data: bytes | int, bytes_separator: str = " ") -> str:
    if isinstance(data, int):
        return "{:02X}".format(data)
    return bytes_separator.join("{:02X}".format(x) for x in data)

from typing import Iterator
 
from response import hex_readable, Response, WorkMode, InventoryWorkMode, InventoryMemoryBank
from transport import SerialTransport, TcpTransport
from reader import Reader
 
transport = SerialTransport('/dev/ttyUSB0', 57600)
# transport = TcpTransport('192.168.1.192', 6000)
reader = Reader(transport)
 
#########################################################
 
# 1. Inventory - Answer Mode
# tags: Iterator[bytes] = reader.inventory_answer_mode()
# for tag in tags:
#     print(f'Tag: {hex_readable(tag)}')
 
#########################################################
 
# 2. Inventory - Active Mode
try:
    responses: Iterator[Response] = reader.inventory_active_mode()
    for response in responses:
        # print(response)
        tag: bytes = response.data
        print(f'Tag: {hex_readable(tag)}')
except KeyboardInterrupt:  # Handle Ctrl + C
    pass
 
#########################################################
 
# 3. Read specific memory, read memory bank TID (0x02), please check 8.2.2 Read Data
# EPC: 12 34 56 78 90 12 34 56 AD EF 01 23
# epc: bytearray = bytearray([0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0xAD, 0xEF, 0x01, 0x23])
# response_read: Response = reader.read_memory(epc=epc, memory_bank=0x02, start_address=0x00, length=0x07)
# print(response_read)
 
#########################################################
 
# 4. Write specific memory, write memory bank EPC (0x01), please check 8.2.3 Write Data
# epc: bytearray = bytearray([0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0xAD, 0xEF, 0x01, 0x23])
# data_to_write: bytearray = bytearray([0x99, 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11, 0x00, 0x99, 0x88])
# response_write: Response = reader.write_memory(epc=epc, memory_bank=0x01, start_address=0x02, data_to_write=data_to_write)
# print(response_write)
 
#########################################################
 
# 5. Lock memory bank, please check 8.2.6 Lock
# EPC: E2 00 A8 32 FE 55 83 91 CE 26 89 AB
# epc: bytearray = bytearray([0xE2, 0x00, 0xA8, 0x32, 0xFE, 0x55, 0x83, 0x91, 0xCE, 0x26, 0x89, 0xAB])
# # access_password: bytes = bytes(4)  # Mean 00 00 00 00 (default access password)
# response_lock: Response = reader.lock(epc=epc, select=0x02, set_protect=0x02, access_password=access_password)
# print(response_lock)
 
#########################################################
 
# 6. Set power, please check 8.4.6 Set Power
# power: int = 28
# response_set_power: Response = reader.set_power(power)
# print(response_set_power)
 
#########################################################
 
# 7. Get & set work mode, please check 8.4.9 Set WorkMode
# work_mode: WorkMode = reader.work_mode()
# print(work_mode)
# # Set buzzer On/Off only works when inventory work mode is set to ACTIVE_MODE
# work_mode.work_mode_state.beep = True
# work_mode.inventory_work_mode = InventoryWorkMode.ACTIVE_MODE
# response_set_work_mode: Response = reader.set_work_mode(work_mode)
# print(response_set_work_mode)
#
# # If you want to set back to ANSWER_MODE, you can use the following code
# work_mode.inventory_work_mode = InventoryWorkMode.ANSWER_MODE
# response_set_answer_mode: Response = reader.set_work_mode(work_mode)
# print(response_set_answer_mode)
 
reader.close()

use std::io::Read;  
use std::io::prelude::*;  
use std::time::Duration;  
use anyhow::{Context, Error};  
use serialport::{ClearBuffer, SerialPort, available_ports};  
use std::net::TcpStream;  
use num_derive::FromPrimitive;  
use num_traits::FromPrimitive;  
  
#[non_exhaustive]  
#[derive(Debug, PartialEq, FromPrimitive, Clone)]  
pub enum BaudRate {  
    Bps9600 = 9600,  
    Bps57600 = 57600,  
    Bps115200 = 115200,  
}  
  
impl From<BaudRate> for u32 {  
    fn from(value: BaudRate) -> Self {  
        value as u32  
    }  
}  
  
#[allow(dead_code)]  
#[derive(Debug)]  
pub struct BaudRateError {  
    pub value: u32,  
}  
  
#[allow(dead_code)]  
impl BaudRate {  
    fn from_u32(value: u32) -> Result<BaudRate, BaudRateError> {  
        FromPrimitive::from_u32(value).ok_or(BaudRateError { value })  
    }  
}  
  
#[allow(dead_code)]  
pub trait Transport {  
    fn read(&mut self) -> Result<Vec<u8>, Error>;  
    fn write(&mut self, buffer: &Vec<u8>) -> Result<(), Error>;  
    fn clear_buffer(&mut self) -> Result<(), Error>;  
    fn close(&mut self) -> Result<(), Error>;  
}  
  
#[allow(dead_code)]  
#[non_exhaustive]  
pub struct SerialTransport<'serial> {  
    serial: Box<dyn SerialPort>,  
  
    pub port: &'serial str,  
    pub baud_rate: BaudRate,  
    pub timeout: u64  
}  
  
impl<'serial> Transport for SerialTransport<'serial> {  
    fn read(&mut self) -> Result<Vec<u8>, Error> {  
        // Get length  
        let mut buffer_length: [u8; 1] = [0u8; 1];  
        self.serial.read(buffer_length.as_mut_slice())  
            .with_context(|| "Can't read buffer length.".to_string())?;  
  
        // Get data by length  
        let mut data: Vec<u8> = vec![0u8; buffer_length[0] as usize];  
        self.serial.read(data.as_mut_slice())  
            .with_context(|| "Can't read buffer data.".to_string())?;  
  
        // Frame (length + data)  
        let mut frame: Vec<u8> = buffer_length.to_vec();  
        frame.extend(data);  
  
        Ok(frame)  
    }  
  
    fn write(&mut self, buffer: &Vec<u8>) -> Result<(), Error> {  
        Ok(  
            self.serial.write_all(buffer)  
                .with_context(|| "Can't write buffer.".to_string())?  
        )  
    }  
  
    fn clear_buffer(&mut self) -> Result<(), Error> {  
        Ok(  
            self.serial.clear(ClearBuffer::All)  
                .with_context(|| "Can't clear all buffer.".to_string())?  
        )  
    }  
  
    fn close(&mut self) -> Result<(), Error> {  
        Ok(())  
    }  
}  
  
impl<'serial> SerialTransport<'serial> {  
    pub fn new(port: &'serial str, baud_rate: BaudRate, timeout: Option<u64>) -> Self {  
        let baud_rate_clone: BaudRate = baud_rate.clone();  
        let timeout: u64 = timeout.unwrap_or(3);  
  
        let serial = serialport::new(port, baud_rate_clone.into())  
            .timeout(Duration::from_secs(timeout))  
            .open().with_context(|| format!("Can't open {}", port)).unwrap();  
  
        SerialTransport {  
            serial,  
            port,  
            baud_rate,  
            timeout,  
        }  
    }  
  
    pub fn scan() -> Vec<String> {  
        let mut ports: Vec<String> = vec![];  
        for port in available_ports().unwrap() {  
            // Windows  
            if port.port_name.contains("COM") {  
                ports.push(port.port_name);  
            }  
  
            // Linux  
            else if port.port_name.contains("/dev/ttyUSB") {  
                ports.push(port.port_name);  
            }  
        }  
        ports  
    }  
}  
  
#[allow(dead_code)]  
#[non_exhaustive]  
pub struct TcpIpTransport<'tcp> {  
    tcp_stream: TcpStream,  
  
    pub ip_address: &'tcp str,  
    pub port: u32,  
    pub timeout: u64  
}  
  
impl<'tcp> Transport for TcpIpTransport<'tcp> {  
    fn read(&mut self) -> Result<Vec<u8>, Error> {  
        // Get length  
        let mut buffer_length: [u8; 1] = [0u8; 1];  
        self.tcp_stream.read(buffer_length.as_mut_slice())  
            .with_context(|| "Can't read buffer length.".to_string())?;  
  
        // Get data by length  
        let mut data: Vec<u8> = vec![0u8; buffer_length[0] as usize];  
        self.tcp_stream.read(data.as_mut_slice())  
            .with_context(|| "Can't read buffer data.".to_string())?;  
  
        // Frame (length + data)  
        let mut frame: Vec<u8> = buffer_length.to_vec();  
        frame.extend(data);  
  
        Ok(frame)  
    }  
  
    fn write(&mut self, buffer: &Vec<u8>) -> Result<(), Error> {  
        Ok(  
            self.tcp_stream.write_all(buffer)  
                .with_context(|| "Can't write buffer.".to_string())?  
        )  
    }  
  
    fn clear_buffer(&mut self) -> Result<(), Error> {  
        todo!()  
    }  
  
    fn close(&mut self) -> Result<(), Error> {  
        Ok(())  
    }  
}  
  
impl<'tcp> TcpIpTransport<'tcp> {  
    pub fn new(ip_address: &'tcp str, port: u32, timeout: Option<u64>) -> Self {  
        let timeout: u64 = timeout.unwrap_or(3);  
  
        let ip_address_port: String = format!("{}:{}", ip_address, port);  
        let tcp_stream = TcpStream::connect(&ip_address_port)  
            .with_context(|| format!("Can't open {}", &ip_address_port)).unwrap();  
  
        // Set timeout  
        tcp_stream.set_read_timeout(Some(Duration::from_secs(timeout))).unwrap();  
        tcp_stream.set_write_timeout(Some(Duration::from_secs(timeout))).unwrap();  
  
        TcpIpTransport {  
            tcp_stream,  
            ip_address,  
            port,  
            timeout,  
        }  
    }  
}

use std::fmt::{Display, Formatter, Result as FmtResult};  
use num_derive::FromPrimitive;  
use num_traits::{FromPrimitive, ToPrimitive};  
use std::convert::From;  
  
#[non_exhaustive]  
#[derive(Debug, Clone, PartialEq, FromPrimitive)]  
pub enum Command {  
    Inventory = 0x01,  
    ReadMemory = 0x02,  
    WriteMemory = 0x03,  
    ReaderInformation = 0x21,  
    SetPower = 0x2F,  
    SetLock = 0x06,  
}  
  
impl From<Command> for u8 {  
    fn from(value: Command) -> Self {  
        value as u8  
    }  
}  
  
#[derive(Debug)]  
pub struct CommandError {  
    pub value: u8,  
}  
  
impl Command {  
    pub fn from_u8(value: u8) -> Result<Command, CommandError> {  
        FromPrimitive::from_u8(value).ok_or(CommandError { value })  
    }  
}  
  
impl Display for Command {  
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {  
        match self {  
            Command::Inventory => write!(f, "Inventory"),  
            Command::ReadMemory => write!(f, "Read memory"),  
            Command::WriteMemory => write!(f, "Write memory"),  
            Command::ReaderInformation => write!(f, "Reader information"),  
            Command::SetPower => write!(f, "Set power"),  
            Command::SetLock => write!(f, "Set lock"),  
        }  
    }  
}  
  
#[allow(dead_code)]  
#[non_exhaustive]  
#[derive(Debug)]  
pub struct CommandRequest {  
    command: Command,  
    reader_address: u8,  
    data: Vec<u8>,  
  
    base_data: Vec<u8>,  
}  
  
impl CommandRequest {  
    pub fn new(command: Command,  
               reader_address: Option<u8>, data: Option<Vec<u8>>) -> CommandRequest {  
        let reader_address: u8 = reader_address.unwrap_or(0xFF);  
        let data: Vec<u8> = data.unwrap_or(Vec::new());  
  
        let frame_length: u8 = (4 + data.len()).to_u8().unwrap();  
        let command_value: u8 = command.clone().into();  
  
        let mut base_data: Vec<u8> = vec![frame_length, reader_address, command_value];  
        let data_base_data_clone = data.clone();  
        base_data.extend(data_base_data_clone);  
  
        CommandRequest {  
            command,  
            reader_address,  
            data,  
            base_data  
        }  
    }  
  
    pub fn serialize(&self) -> Vec<u8> {  
        let checksum: u16 = self.calculate_crc();  
        let mut frame: Vec<u8> = self.base_data.clone();  
  
        frame.push((checksum & 0xFF) as u8);  
        frame.push((checksum >> 8) as u8);  
  
        frame  
    }  
  
    fn calculate_crc(&self) -> u16 {  
        let mut value = 0xFFFF;  
        for &byte in self.base_data.iter() {  
            value ^= u16::from(byte);  
            for _ in 0..8 {  
                value = if value & 0x0001 != 0 {  
                    (value >> 1) ^ 0x8408  
                } else {  
                    value >> 1  
                };  
            }  
        }  
        value  
    }  
}

use std::fmt::{Display, Formatter, Result as FmtResult};  
use num_derive::FromPrimitive;  
use num_traits::{FromPrimitive, ToPrimitive};  
use crate::command::Command;  
use crate::utils::hex_readable;  
  
#[non_exhaustive]  
#[derive(Debug, Clone, PartialEq, FromPrimitive)]  
pub enum Status {  
    Success = 0x00,  
  
    ReturnBeforeInvFinish = 0x01,  
    InvOverflow = 0x02,  
    MoreData = 0x03,  
    FlashFull = 0x04,  
  
    InvalidAccessPwd = 0x05,  
    InvalidKillPwd = 0x09,  
    KillPwdNoZero = 0x0A,  
    UnsupportedCommand = 0x0B,  
    AccessPwdNoZero = 0x0C,  
    TagProtected = 0x0D,  
    TagUnprotected = 0x0E,  
  
    WriteError6B = 0x10,  
    LockError6B = 0x11,  
    TagProtected6B = 0x12,  
  
    SaveError = 0x13,  
    PowerLocked = 0x14,  
  
    ReturnBeforeInvFinish6B = 0x15,  
    InvOverflow6B = 0x16,  
    MoreData6B = 0x17,  
    FlashFull6B = 0x18,  
    EasAlarmError = 0x19,  
  
    CommandError = 0xF9,  
    WeakSignal = 0xFA,  
    NoTagFound = 0xFB,  
    TagError = 0xFC,  
    InvalidCommandLength = 0xFD,  
    CommandNotFound = 0xFE,  
    ParameterError = 0xFF,  
}  
  
impl From<Status> for u8 {  
    fn from(value: Status) -> Self {  
        value as u8  
    }  
}  
  
impl Display for Status {  
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {  
        match self {  
            Status::Success => write!(f, "Success"),  
            Status::ReturnBeforeInvFinish => write!(f, "Return before inventory finished"),  
            Status::InvOverflow => write!(f, "Inventory scan time overflow"),  
            Status::MoreData => write!(f, "More data"),  
            Status::FlashFull => write!(f, "Reader module flash is full"),  
  
            Status::InvalidAccessPwd => write!(f, "Invalid access password"),  
            Status::InvalidKillPwd => write!(f, "Invalid kill password"),  
            Status::KillPwdNoZero => write!(f, "Kill password error can't be zero"),  
            Status::UnsupportedCommand => write!(f, "Unsupported command"),  
            Status::AccessPwdNoZero => write!(f, "Access password error can't be zero"),  
            Status::TagProtected => write!(f, "Tag protected"),  
            Status::TagUnprotected => write!(f, "Tag unprotected"),  
  
            Status::WriteError6B => write!(f, "Write error, some bytes locked for 6B tag"),  
            Status::LockError6B => write!(f, "Lock error, can't lock for 6B tag"),  
            Status::TagProtected6B => write!(f, "Tag protected for 6B tag"),  
  
            Status::SaveError => write!(f, "Save fail, the parameter save is error"),  
            Status::PowerLocked => write!(f, "Power locked"),  
  
            Status::ReturnBeforeInvFinish6B => write!(f, "Return before inventory \  
            finished for 6B tag"),  
            Status::InvOverflow6B => write!(f, "Inventory scan time overflow for 6B tag"),  
            Status::MoreData6B => write!(f, "More data for 6B tag"),  
            Status::FlashFull6B => write!(f, "Reader module flash is full for 6B tag"),  
            Status::EasAlarmError => write!(f, "EAS Alarm error / unsupported command \  
            / invalid access password"),  
  
            Status::CommandError => write!(f, "Command error"),  
            Status::WeakSignal => write!(f, "Weak signal, bring tag closer"),  
            Status::NoTagFound => write!(f, "No tag found"),  
            Status::TagError => write!(f, "Tag error"),  
            Status::InvalidCommandLength => write!(f, "Invalid command length"),  
            Status::CommandNotFound => write!(f, "Command not found"),  
            Status::ParameterError => write!(f, "Parameter error"),  
  
            // _ => write!(f, "Error not found")  
        }  
    }  
}  
  
#[allow(dead_code)]  
#[derive(Debug)]  
pub struct StatusError {  
    pub value: u8,  
}  
  
#[allow(dead_code)]  
impl StatusError {  
    pub fn from_u8(value: u8) -> Result<Status, StatusError> {  
        FromPrimitive::from_u8(value).ok_or(StatusError { value })  
    }  
}  
  
#[non_exhaustive]  
#[derive(Debug)]  
pub struct Response {  
    pub length: u8,  
    pub reader_address: u8,  
    pub command: Command,  
    pub status: Status,  
    pub data: Vec<u8>,  
    pub checksum: Vec<u8>,  
}  
  
impl Response {  
    // TODO: Check CommandError  
  
    pub fn new(response: &Vec<u8>) -> Response {  
        Response {  
            length: response[0],  
            reader_address: response[1],  
            command: Command::from_u8(response[2]).unwrap(),  
            status: Status::from_u8(response[3]).unwrap(),  
            data: response[4..response.len() - 2].to_owned(),  
            checksum: response[response.len() - 2..].to_owned(),  
        }  
    }  
}  
  
impl Display for Response {  
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {  
        write!(f,  
               "Response {{  
               length: {},  
               reader_address: {},  
               command: {},  
               status: {},  
               data: {},  
               checksum: {}  
               }}",  
               self.length,  
               hex_readable(&[self.reader_address]),  
               self.command,  
               self.status,  
               hex_readable(&self.data),  
               hex_readable(&self.checksum)  
        )  
    }  
}  
  
#[non_exhaustive]  
pub struct ResponseInventory<'rsp> {  
    pub response: &'rsp Response,  
    pub tags: Vec<&'rsp [u8]>,  
}  
  
impl<'rsp> ResponseInventory<'rsp> {  
    pub fn new(response: &'rsp Response) -> ResponseInventory {  
        let mut tags: Vec<&[u8]> = Vec::new();  
  
        if response.data.len() != 0 {  
            let tag_count = response.data[0];  
            let mut pointer: usize = 1;  
            for _ in 0..tag_count {  
                let tag_length: usize = response.data[pointer].to_usize().unwrap();  
                let tag_data_start: usize = pointer + 1;  
                let tag_main_start: usize = tag_data_start;  
                let tag_main_end: usize = tag_main_start + tag_length;  
                let next_tag_start: usize = tag_main_end;  
                let tag: &[u8] = &response.data[tag_main_start..tag_main_end];  
                pointer = next_tag_start;  
                tags.push(tag);  
            }  
        }  
  
        ResponseInventory {  
            response,  
            tags  
        }  
    }  
}

use num_traits::{ToPrimitive, FromPrimitive};  
use num_derive::FromPrimitive;  
use thiserror::Error;  
use crate::command::{Command, CommandError, CommandRequest};  
use crate::response::{Response, ResponseInventory};  
use crate::transport::Transport;  
  
#[non_exhaustive]  
#[derive(Debug, Clone, PartialEq, FromPrimitive)]  
pub enum MemoryBank {  
    Password = 0x00,  
    EPC = 0x01,  
    TID = 0x02,  
    User = 0x03,  
}  
  
impl From<MemoryBank> for u8 {  
    fn from(value: MemoryBank) -> Self {  
        value as u8  
    }  
}  
  
#[derive(Debug)]  
pub struct MemoryBankError {  
    pub value: u8,  
}  
  
impl MemoryBank {  
    pub fn from_u8(value: u8) -> Result<MemoryBank, MemoryBankError> {  
        FromPrimitive::from_u8(value).ok_or(MemoryBankError { value })  
    }  
}  
  
#[allow(dead_code)]  
#[non_exhaustive]  
#[derive(Debug, Error)]  
pub enum ReaderError {  
    #[error("Invalid command: {value}")]  
    InvalidCommand {  
        value: u8  
    },  
    #[error("Invalid response")]  
    InvalidResponse,  
}  
  
  
impl From<CommandError> for ReaderError {  
    fn from(error: CommandError) -> Self {  
        Self::InvalidCommand{ value: error.value }  
    }  
}  
  
#[non_exhaustive]  
pub struct Reader {  
    pub reader_address: u8,  
    pub transport: Box<dyn Transport>,  
}  
  
impl Reader {  
    pub fn new(transport: impl Transport + 'static, reader_address: Option<u8>) -> Reader {  
        let reader_address: u8 = reader_address.unwrap_or(0xFF);  
  
        Reader {  
            reader_address,  
            transport: Box::new(transport)  
        }  
    }  
  
    pub fn inventory_answer_mode(&mut self) -> Vec<Vec<u8>> {  
        let command: CommandRequest = CommandRequest::new(Command::Inventory,  
                                                          Some(self.reader_address),  
                                                          None);  
        self.transport.write(&command.serialize()).unwrap();  
  
        let read_result = self.transport.read();  
        let frame: Vec<u8> = read_result.unwrap();  
  
        let response: Response = Response::new(&frame);  
        let response_inventory: ResponseInventory = ResponseInventory::new(&response);  
        let tags: Vec<Vec<u8>> = response_inventory.tags  
            .iter().map(|tag| tag.to_vec()).collect();  
        tags  
    }  
  
    pub fn read_memory(&mut self, selected_epc: &[u8], memory_bank: MemoryBank,  
                       start_address: u8, length: u8,  
                       access_password: Option<[u8; 4]>) -> Response {  
        let epc_length: u8 = (selected_epc.len() / 2).to_u8().unwrap();  
        let mask_length: u8 = selected_epc.len().to_u8().unwrap();  
  
        let mut command_data: Vec<u8> = vec![epc_length];  
        command_data.extend(selected_epc);  
        command_data.extend([memory_bank.into(), start_address, length]);  
        command_data.extend(access_password.unwrap_or([0u8; 4]));  
        command_data.extend([0x00, mask_length]);  
  
        let command: CommandRequest = CommandRequest::new(Command::ReadMemory,  
                                                          Some(self.reader_address),  
                                                          Some(command_data));  
        self.transport.write(&command.serialize()).unwrap();  
        let read_result = self.transport.read();  
        let frame: Vec<u8> = read_result.unwrap();  
        Response::new(&frame)  
    }  
  
    pub fn write_memory(&mut self, data_to_write: Vec<u8>, selected_epc: &[u8],  
                        memory_bank: MemoryBank, start_address: u8,  
                        access_password: Option<[u8; 4]>) -> Response {  
        let data_to_write_length: u8 = (data_to_write.len() / 2).to_u8().unwrap();  
        let epc_length: u8 = (selected_epc.len() / 2).to_u8().unwrap();  
        let mask_length: u8 = selected_epc.len().to_u8().unwrap();  
  
        let mut command_data: Vec<u8> = vec![data_to_write_length, epc_length];  
        command_data.extend(selected_epc);  
        command_data.extend([memory_bank.into(), start_address]);  
        command_data.extend(data_to_write);  
        command_data.extend(access_password.unwrap_or([0u8; 4]));  
        command_data.extend([0x00, mask_length]);  
  
        let command: CommandRequest = CommandRequest::new(Command::WriteMemory,  
                                                          Some(self.reader_address),  
                                                          Some(command_data));  
        self.transport.write(&command.serialize()).unwrap();  
        let read_result = self.transport.read();  
        let frame: Vec<u8> = read_result.unwrap();  
        Response::new(&frame)  
    }  
}

pub fn hex_readable(buffer: &[u8]) -> String {  
    let mut result = String::new();  
  
    for (i, byte) in buffer.iter().enumerate() {  
        result.push_str(  
            &format!("{:02X}{}", byte, if i + 1 == buffer.len() { "" } else { " " })  
        );  
    }  
    result  
}

mod transport;  
mod command;  
mod response;  
mod utils;  
mod reader;  
  
fn main() {  
    println!("Hello, world!");  
}  
  
#[cfg(test)]  
mod test {  
    use crate::reader::{MemoryBank, Reader};  
    use crate::transport::{BaudRate, SerialTransport, TcpIpTransport};  
    use crate::utils::hex_readable;  
  
    #[test]  
    pub fn test_reader() {  
        //// Serial  
        // let ports: Vec<String> = SerialTransport::scan();        // println!("Ports: {:?}", ports);        // let transport: SerialTransport = SerialTransport::new("/dev/ttyUSB0",        //                                                       BaudRate::Bps57600, Some(3));  
        //// TCP IP       let transport: TcpIpTransport = TcpIpTransport::new("192.168.1.198",  
                                                           6000, Some(3));  
        let mut reader: Reader = Reader::new(transport, Some(0xFF));  
  
        //// Inventory - Answer Mode  
        let tags = reader.inventory_answer_mode();  
        for tag in tags.iter() {  
            println!("Tag: {}", hex_readable(tag));  
        }  
        if tags.len() == 0 {  
            return;  
        }  
  
        //// Read memory  
        let selected_tag: &Vec<u8> = &tags[0];  
        let response_read_memory = reader.read_memory(selected_tag,  
                                                      MemoryBank::TID, 0, 6,  
                                                      None);  
        println!("{response_read_memory}");  
        println!("Data (TID): {}", hex_readable(&response_read_memory.data));  
  
        //// Write memory  
        // let data_to_write: Vec<u8> = vec![0x30, 0x00,        //                                   0x11, 0x22, 0x33, 0x44, 0x55, 0x66,        //                                   0x77, 0x88, 0x99, 0x00, 0xAA, 0xB1];        // let response_write_memory = reader.write_memory(data_to_write, selected_tag,        //                                                 MemoryBank::EPC, 0x01, None);        // println!("{response_write_memory}");        // println!("Write - status: {}", response_write_memory.status);    }  
}

import java.net.Socket;
import com.fazecast.jSerialComm.SerialPort;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
 
abstract class Transport {
    public abstract byte[] readBytes(int length) throws IOException;
 
    public abstract void writeBytes(byte[] buffer) throws IOException;
 
    public byte[] readFrame() throws IOException {
        byte[] lengthBytes = readBytes(1);
        if (lengthBytes.length == 0) {
            return null;
        }
 
        int frameLength = lengthBytes[0] & 0xFF; // Convert byte to int
        byte[] data = new byte[1 + frameLength]; // Full frame
        System.arraycopy(lengthBytes, 0, data, 0, 1);
        byte[] payload = readBytes(frameLength);
        System.arraycopy(payload, 0, data, 1, frameLength);
 
        return data;
    }
 
    public abstract void close();
}
 
class TcpTransport extends Transport {
    private final Socket socket;
    private final InputStream inputStream;
    private final OutputStream outputStream;
 
    public TcpTransport(String ipAddress, int port, int timeout) throws IOException {
        this.socket = new Socket(ipAddress, port);
        this.socket.setSoTimeout(timeout * 1000);
        this.inputStream = socket.getInputStream();
        this.outputStream = socket.getOutputStream();
    }
 
    @Override
    public byte[] readBytes(int length) throws IOException {
        byte[] buffer = new byte[length];
        int bytesRead = inputStream.read(buffer);
        if (bytesRead == -1) {
            throw new IOException("End of stream reached");
        }
        return buffer;
    }
 
    @Override
    public void writeBytes(byte[] buffer) throws IOException {
        outputStream.write(buffer);
        outputStream.flush();
    }
 
    @Override
    public void close() {
        try {
            socket.close();
            System.out.println("Port closed.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
 
class SerialTransport extends Transport {
    private final SerialPort serialPort;
    private final InputStream inputStream;
    private final OutputStream outputStream;
 
    public SerialTransport(String portName, int baudRate, int timeout) {
        serialPort = SerialPort.getCommPort(portName);
        serialPort.setBaudRate(baudRate);
        serialPort.setNumDataBits(8);
        serialPort.setNumStopBits(SerialPort.ONE_STOP_BIT);
        serialPort.setParity(SerialPort.NO_PARITY);
        serialPort.setComPortTimeouts(SerialPort.TIMEOUT_READ_BLOCKING, timeout * 1000, timeout * 1000);
 
        if (serialPort.openPort()) {
            serialPort.flushDataListener();
 
            System.out.println("Port opened: " + portName);
            inputStream = serialPort.getInputStream();
            outputStream = serialPort.getOutputStream();
        } else {
            throw new RuntimeException("Failed to open port: " + portName);
        }
    }
 
    @Override
    public byte[] readBytes(int length) throws IOException {
        byte[] buffer = new byte[length];
        int bytesRead = inputStream.read(buffer);
        if (bytesRead < 0) {
            throw new IOException("No data read from serial port.");
        }
        return buffer;
    }
 
    @Override
    public void writeBytes(byte[] buffer) throws IOException {
        outputStream.write(buffer);
        outputStream.flush();
    }
 
    @Override
    public void close() {
        try {
            inputStream.close();
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        serialPort.closePort();
        System.out.println("Port closed.");
    }
}
 

import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
 
class Command {
    private final byte[] baseData;
 
    public Command(int command, int readerAddress, Object data) {
 
        byte[] dataTemp;
        if (data instanceof Integer) {
            dataTemp = new byte[]{(byte) ((int) data)};
        } else if (data instanceof byte[]) {
            dataTemp = (byte[]) data;
        } else {
            dataTemp = new byte[0];
        }
 
        int frameLength = 4 + dataTemp.length;
        List<Byte> baseDataList = new ArrayList<>();
        baseDataList.add((byte) frameLength);
        baseDataList.add((byte) readerAddress);
        baseDataList.add((byte) command);
        for (byte b : dataTemp) {
            baseDataList.add(b);
        }
 
        this.baseData = new byte[baseDataList.size()];
        for (int i = 0; i < baseDataList.size(); i++) {
            this.baseData[i] = baseDataList.get(i);
        }
    }
 
    public byte[] serialize() {
        byte[] checksum = Utils.calculateChecksum(this.baseData);
        ByteBuffer buffer = ByteBuffer.allocate(this.baseData.length + checksum.length);
        buffer.put(this.baseData);
        buffer.put(checksum);
        return buffer.array();
    }
}
 

import java.util.Arrays;
 
class Response {
    public byte[] responseBytes;
    public int length;
    public int readerAddress;
    public int command;
    public int status;
    public byte[] data;
    public byte[] checksum;
 
    public Response(byte[] responseBytes) {
        if (responseBytes.length < 6) {
            throw new IllegalArgumentException("Response data is too short to be valid.");
        }
 
        this.responseBytes = responseBytes;
        this.length = Byte.toUnsignedInt(responseBytes[0]);
 
        if (responseBytes.length < this.length) {
            throw new IllegalArgumentException("Response length mismatch.");
        }
 
        this.readerAddress = Byte.toUnsignedInt(responseBytes[1]);
        this.command = Byte.toUnsignedInt(responseBytes[2]);
        this.status = Byte.toUnsignedInt(responseBytes[3]);
 
        this.data = Arrays.copyOfRange(responseBytes, 4, this.length - 1);
        this.checksum = Arrays.copyOfRange(responseBytes, this.length - 1, this.length + 1);
 
        // Verify checksum
        byte[] dataForChecksum = new byte[4 + this.data.length];
        System.arraycopy(responseBytes, 0, dataForChecksum, 0, 4);
        System.arraycopy(this.data, 0, dataForChecksum, 4, this.data.length);
 
        byte[] calculatedChecksum = calculateChecksum(dataForChecksum);
        if (this.checksum[0] != calculatedChecksum[0] || this.checksum[1] != calculatedChecksum[1]) {
            throw new IllegalArgumentException("Checksum verification failed.");
        }
    }
 
    public String toString() {
        StringBuilder returnValue = new StringBuilder();
        returnValue.append(">>> START RESPONSE ================================\n");
        returnValue.append("RESPONSE       >> ").append(Utils.hexReadable(this.responseBytes)).append("\n");
        returnValue.append("READER ADDRESS >> ").append(Utils.hexReadable(this.readerAddress)).append("\n");
        returnValue.append("COMMAND        >> ").append(Utils.hexReadable(this.command)).append("\n");
        returnValue.append("STATUS         >> ").append(Utils.hexReadable(this.status)).append("\n");
        if (this.data.length > 0) {
            returnValue.append("DATA           >> ").append(Utils.hexReadable(this.data)).append("\n");
        }
        returnValue.append("CHECKSUM       >> ").append(Utils.hexReadable(this.checksum)).append("\n");
        returnValue.append(">>> END RESPONSE   ================================");
        return returnValue.toString();
    }
 
    private byte[] calculateChecksum(byte[] data) {
        int value = 0xFFFF;
        for (byte d : data) {
            value ^= (d & 0xFF);
            for (int i = 0; i < 8; i++) {
                if ((value & 0x0001) != 0) {
                    value = (value >> 1) ^ 0x8408;
                } else {
                    value = value >> 1;
                }
            }
        }
        byte crcLsb = (byte) (value & 0xFF);
        byte crcMsb = (byte) ((value >> 8) & 0xFF);
        return new byte[]{crcLsb, crcMsb};
    }
}
 

public class Utils {
    public static byte[] calculateChecksum(byte[] data) {
        int value = 0xFFFF;
        for (byte d : data) {
            value ^= (d & 0xFF);
            for (int i = 0; i < 8; i++) {
                if ((value & 0x0001) != 0) {
                    value = (value >> 1) ^ 0x8408;
                } else {
                    value = value >> 1;
                }
            }
        }
        byte crcLsb = (byte) (value & 0xFF);
        byte crcMsb = (byte) ((value >> 8) & 0xFF);
        return new byte[]{crcLsb, crcMsb};
    }
 
    public static String hexReadable(int data) {
        return String.format("%02X", data);
    }
 
    public static String hexReadable(byte[] data) {
        StringBuilder sb = new StringBuilder();
        for (byte b : data) {
            sb.append(String.format("%02X ", b));
        }
        return sb.toString().trim();
    }
}

import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.concurrent.TimeoutException;
 
public class Reader {
    private final Transport transport;
 
    public Reader(Transport transport) {
        this.transport = transport;
    }
 
    public void close() throws IOException {
        transport.close();
    }
 
    private void sendRequest(Command command) throws IOException {
        transport.writeBytes(command.serialize());
    }
 
    private byte[] getResponse() throws IOException {
        return transport.readFrame();
    }
 
    public Iterator<Response> inventoryActiveMode() {
        return new Iterator<>() {
            @Override
            public boolean hasNext() {
                return true;
            }
 
            @Override
            public Response next() {
                while (true) {
                    try {
                        byte[] rawResponse = getResponse();
                        if (rawResponse != null && rawResponse.length > 0) {
                            return new Response(rawResponse);
                        }
                    } catch (IOException e) {
                        // Check if the exception is due to a timeout and continue looping
                        if (e.getMessage().contains("timed out")) {
                            continue; // Ignore timeout and retry
                        }
                        throw new NoSuchElementException("Error retrieving response: " + e.getMessage());
                    }
                }
            }
        };
    }
 
    public Iterator<byte[]> inventoryAnswerMode() throws IOException { // 8.2.1 Inventory (Answer Mode)
        Command command = new Command(0x01, 0xFF, null);
        sendRequest(command);
 
        Response response = new Response(getResponse());
        byte[] data = response.data;
 
        if (data.length == 0) {
            return new EmptyIterator<>();
        }
 
        return new InventoryIterator(data);
    }
 
    public Response readMemory(byte[] epc, int memoryBank, int startAddress, int length, byte[] accessPassword) throws IOException {
        byte[] requestData = new byte[epc.length + 8];
        requestData[0] = (byte) (epc.length / 2);
        System.arraycopy(epc, 0, requestData, 1, epc.length);
        requestData[epc.length + 1] = (byte) memoryBank;
        requestData[epc.length + 2] = (byte) startAddress;
        requestData[epc.length + 3] = (byte) length;
        System.arraycopy(accessPassword, 0, requestData, epc.length + 4, 4);
 
        Command command = new Command(0x02, 0xFF, requestData);
        sendRequest(command);
 
        return new Response(getResponse());
    }
 
    public Response writeMemory(byte[] epc, int memoryBank, int startAddress, byte[] dataToWrite, byte[] accessPassword) throws IOException {
        byte[] requestData = new byte[dataToWrite.length + epc.length + 8];
        requestData[0] = (byte) (dataToWrite.length / 2);
        requestData[1] = (byte) (epc.length / 2);
        System.arraycopy(epc, 0, requestData, 2, epc.length);
        requestData[epc.length + 2] = (byte) memoryBank;
        requestData[epc.length + 3] = (byte) startAddress;
        System.arraycopy(dataToWrite, 0, requestData, epc.length + 4, dataToWrite.length);
        System.arraycopy(accessPassword, 0, requestData, epc.length + dataToWrite.length + 4, 4);
 
        Command command = new Command(0x03, 0xFF, requestData);
        sendRequest(command);
 
        return new Response(getResponse());
    }
 
    public Response setPower(int power) throws IOException {
        Command command = new Command(0x2F, 0xFF, new byte[]{(byte) power});
        sendRequest(command);
 
        return new Response(getResponse());
    }
 
    private static class InventoryIterator implements Iterator<byte[]> {
        private final byte[] data;
        private int pointer = 1;
        private final int tagCount;
        private int count = 0;
 
        InventoryIterator(byte[] data) {
            this.data = data;
            this.tagCount = data[0];
        }
 
        @Override
        public boolean hasNext() {
            return count < tagCount;
        }
 
        @Override
        public byte[] next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }
 
            int tagLen = data[pointer] & 0xFF;
            int tagStart = pointer + 1;
            int tagEnd = tagStart + tagLen;
            byte[] tag = new byte[tagLen];
            System.arraycopy(data, tagStart, tag, 0, tagLen);
 
            pointer = tagEnd;
            count++;
            return tag;
        }
    }
 
    private static class EmptyIterator<T> implements Iterator<T> {
        @Override
        public boolean hasNext() {
            return false;
        }
 
        @Override
        public T next() {
            throw new NoSuchElementException();
        }
    }
}