#include <Arduino.h>
#include "UID.h"

void setup()
{
    Serial.begin(115200);
    
    /* pruebecillas */
    String sUid = "10bbccdf";
    UID_t auxUid;
    if (auxUid.fromString(sUid))
        auxUid.printUID();
    else
        Serial.println("LLave no válida");
    String s;
    auxUid.toStringPretty(s);
    Serial.printf("UID guapa: %s\n", s);
}

void loop()
{
}

sketch.ino

diagram.json

# Wokwi Library List
# See https://docs.wokwi.com/guides/libraries

ArduinoJson


libraries.txt

/**************************************************************
   UID
   (c) 2024 Juan M. Uribe

   Settings for handling Rfid UID keys
 ***************************************************************/
#pragma once
#define REG_COUNT 10 // Maximum size of key
#include <vector>

using namespace std;

class UID_t
{
  private:
    uint8_t keySize;
    vector<uint8_t> keyUID;

  public:
    uint8_t size();
    void size(uint8_t size);
    void printUID();
    uint8_t keyValue(int i);
    void keyValue(int i, uint8_t value);
    void toString(String &s);
    void toStringPretty(String &s);
    bool fromString(const String &s);
    friend bool operator==(const UID_t &uid1, const UID_t &uid2);
    friend bool operator!=(const UID_t &uid1, const UID_t &uid2);
    UID_t &operator=(const UID_t &value);
};

uint8_t UID_t::size()
{
  return keySize;
}

void UID_t::size(uint8_t size)
{
  keySize = size;
  keyUID.resize(size);
}

uint8_t UID_t::keyValue(int i)
{
  return keyUID[i];
}

void UID_t::keyValue(int i, uint8_t value)
{
  keyUID[i] = value;
}

void UID_t::printUID()
{
  for (int i = 0; i < keySize; i++)
  {
    Serial.printf("%02X ", keyUID[i]);
  }
  Serial.println();
}

void UID_t::toString(String &s)
{
  char aux[10];
  for (int i = 0; i < keySize; i++)
  {
    sprintf(aux, "%02X", keyUID[i]);
    s += aux;
  }
}

void UID_t::toStringPretty(String &s)
{
  char aux[10];
  for (int i = 0; i < keySize-1; i++)
  {
    sprintf(aux, "%02X ", keyUID[i]);
    s += aux;
  }
  sprintf(aux, "%02X", keyUID[keySize-1]);
  s+= aux;
}


bool UID_t::fromString(const String &s)
{
  // Check valid characters and remove spaces
  String auxString;
  for (int i = 0; i < s.length(); i++) {
    if (int(s[i]) != 0x20 && isxdigit(s[i])) {
      auxString += s[i];
    }
  }
  // Check the proper length
  uint16_t len = auxString.length() / 2;
  if ((len != 4) && (len != 7) && (len != 10) || (auxString.length() % 2 != 0)) {
    return false;
  }
  // Convert
  size(len);
  String substring;
  char str[2];
  unsigned char data;
  for (int i = 0; i < keySize; i++)
  {
    substring = auxString.substring(i * 2, (i + 1) * 2);
    substring.toCharArray(str, substring.length() + 1);
    data = strtoul(str, nullptr, 16);
    keyUID[i] = data;
  }
  return true;
}

bool operator!=(const UID_t & uid1, const UID_t & uid2)
{
  bool result = false;
  if (uid1.keySize != uid2.keySize)
    result = true;
  else
  {
    for (int i = 0; i < uid1.keySize; i++)
    {
      if (uid1.keyUID[i] != uid2.keyUID[i])
        result = true;
    }
  }
  return result;
}

bool operator==(const UID_t & uid1, const UID_t & uid2)
{
  return !(uid1 != uid2);
}

UID_t &UID_t::operator=(const UID_t & value)
{
  keySize = value.keySize;
  keyUID = value.keyUID;
  return *this;
}
