RFID WL-134A 十六进制解码 Arduino

Question

我有一个连接到 Arduino 模块的动物标签阅读器，并且由于用户 red_car 成功读取了数据，但我遇到了标签 ID 不正确的问题，它似乎通过了校验和并提供了给定标签的正确国家/地区代码。但标签数据解码错误。该系统有一个手册（附照片），它似乎与 red_car 示例中的结构匹配，但标签 ID 始终是错误的。

因此，为了隔离问题，我更改了从手动设置的代码中读取的代码，并输入了手册中的示例。

例子是：

02 31 37 31 41 39 32 35 33 41 33 34 38 33 30 30 31 30 30 30 30 30 30 30 30 30 30 07 f8 03 通过 ASICII 转换时：171A9253A34830010000000000

其中包含： 标签ID：1-10字节（10长） 国家代码字节 11-14（4 个长）

171A9253A3 483 0010000000000

应生成：国家/地区：900 标签：250000023921

byte buffer[30] = {0x02, 0x31, 0x37, 0x31, 0x41, 0x39, 0x32, 0x35, 0x33, 0x41, 0x33, 0x34, 0x38, 0x33, 0x30, 0x30, 0x31, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x07, 0xf8, 0x03};
byte b;
uint8_t idx;
boolean started = false;

byte     XOR;
byte     inverted;

uint32_t   value;


void setup() {
  // Initialize serial communication at 9600 baud
  Serial.begin(9600);
  delay(1000);
  Serial.println("start:");
}

void loop() {
  
        // Print the contents of the buffer to Serial Monitor for verification
        for (int i = 0; i < sizeof(buffer); i++) {
          Serial.print(buffer[i], HEX);
          Serial.print(" ");
        }
        Serial.println();

        // Check we received the message ok.  XOR checksum on bytes 01-26 should match byte 27.
        XOR = buffer[1];
        for (int x = 2; x <= 26; x++)
        {
          XOR ^= buffer[x];  
        }
        Serial.print("Calculated checksum: ");
        Serial.print(XOR, HEX);

        if (XOR == buffer[27])
          Serial.println(" (Correct)");
        else
          Serial.println(" (Error)");


        // Check the inverted XOR checksum
        inverted = ~XOR;
        Serial.print("Inverted checksum: ");
        Serial.print(inverted, HEX);
        if (inverted == buffer[28])
          Serial.println(" (Correct)");
        else
          Serial.println(" (Error)");

        
        // Extract the card number from bytes 01 (LSB) - 10 (MSB).
        value = 0;
        for (int x = 10; x >= 1; x--)
        {
          if(buffer[x] <= '9')
            value = (value<<4) + buffer[x] - '0';  
          else
            value = (value<<4) + buffer[x] - '7';  
        }
        Serial.print("Card number: ");
        Serial.println(value);


        // Extract the country number from bytes 11 (LSB) - 14 (MSB).
        value = 0;
        for (int x = 14; x >= 11; x--)
        {
          if(buffer[x] <= '9')
            value = (value<<4) + buffer[x] - '0';
          else
            value = (value<<4) + buffer[x] - '7';  
        }
        Serial.print("Country number: ");
        Serial.println(value);


        // Extract the Data Block from byte 15.
        Serial.print("Data block: ");
        Serial.println(buffer[15] - '0');

        
        // Extract the Animal Flag from byte 16.
        Serial.print("Animal flag: ");
        Serial.println(buffer[16] - '0');

        Serial.println("\r");
delay(100000);
}

返回卡 ID：891920753

2 31 37 31 41 39 32 35 33 41 33 34 38 33 30 30 31 30 30 30 30 30 30 30 30 30 30 7 F8 3 
Calculated checksum: 7 (Correct)
Inverted checksum: F8 (Correct)
Card number: 891920753
Country number: 900
Data block: 0
Animal flag: 1

Answer 1

这是将您的输入转换为实际值的方法。 我把校验和计算留给你:)

#include <array>
#include <cstdint>
#include <iostream>

std::array<std::uint8_t, 30> buffer = { 0x02, 0x31, 0x37, 0x31, 0x41, 0x39, 0x32, 0x35, 0x33, 0x41, 0x33, 0x34, 0x38, 0x33, 0x30,
                                        0x30, 0x31, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x07, 0xf8, 0x03 };

// helper function to convecrt ascii hex character to a decimal number
std::uint64_t from_hex(const char c)
{
    if(c >= '0' && c <= '9')
        return c - '0';
    return c - 'A' + 10;
}

struct tag_info_t
{
    tag_info_t(const std::array<std::uint8_t, 30>& buffer)
    {
        // copy the data from the buffer to the struct
        std::memcpy(&m_data, buffer.data(), sizeof(tag_info_t));

        // then convert the ascii hex values to a single integer
        // start at last digit and work forwards
        for(int i = static_cast<int>(m_data.tag_id.size()-1); i >= 0; --i)
        {
            // each time we get to a new character the current
            // value is shifted left by 4 bits (multiplied by 16)
            m_tag_id = (m_tag_id << 4);

            // then we convert the current character in the input buffer 
            // to a number and add it to the current value
            m_tag_id += from_hex(m_data.tag_id[i]);
        }

        for(int i = static_cast<int>(m_data.country_id.size()-1); i >= 0; --i)
        {
            m_country_id = (m_country_id << 4);
            m_country_id += from_hex(m_data.country_id[i]);
        }
    }

    bool validate()
    {
        if(m_data.start_byte != 0x02)
            return false;
        if(m_data.end_byte != 0x03)
            return false;
        //TODO checksum
        return true;
    }

    std::uint64_t get_tag_id() const noexcept
    {
        return m_tag_id;
    }

    std::uint64_t get_country_id() const noexcept
    {
        return m_country_id;
    }

private:
    // not strictly needed
    // you can index into the raw array directly
    // but this lets me show you a bit more clearly
    // where I am getting the bytes from
    struct data_block_t
    {
        std::uint8_t start_byte;
        std::array<std::uint8_t, 10> tag_id;
        std::array<std::uint8_t, 4> country_id;
        std::uint8_t data_block;
        std::uint8_t animal_flag;
        std::array<std::uint8_t, 4> reserved4;
        std::array<std::uint8_t, 6> reserved6;
        std::uint8_t crc1;
        std::uint8_t crc2;
        std::uint8_t end_byte;
    };

    data_block_t m_data;
    std::uint64_t m_country_id{};
    std::uint64_t m_tag_id{};
};

int main()
{
    tag_info_t tag_info{ buffer };
    if(tag_info.validate())
    {
        std::cout << "Country ID: " << tag_info.get_country_id() << "\n";
        std::cout << "Tag ID: " << tag_info.get_tag_id() << "\n";
    }

    return 0;
}