initial commit

utils/crc16.ts

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+
+/**
+ * Calculates CRC16 according to the UHF Reader Manual.
+ * Polynomial: 0x8408
+ * Preset: 0xFFFF
+ */
+export const calculateCRC16 = (data: Uint8Array): number => {
+  const PRESET_VALUE = 0xFFFF;
+  const POLYNOMIAL = 0x8408;
+
+  let uiCrcValue = PRESET_VALUE;
+
+  for (let i = 0; i < data.length; i++) {
+    uiCrcValue = uiCrcValue ^ data[i];
+    for (let j = 0; j < 8; j++) {
+      if ((uiCrcValue & 0x0001) !== 0) {
+        uiCrcValue = (uiCrcValue >> 1) ^ POLYNOMIAL;
+      } else {
+        uiCrcValue = (uiCrcValue >> 1);
+      }
+    }
+  }
+
+  return uiCrcValue;
+};
+
+/**
+ * Splits a 16-bit CRC into LSB and MSB bytes
+ */
+export const getCRCBytes = (crc: number): [number, number] => {
+  const lsb = crc & 0xFF;
+  const msb = (crc >> 8) & 0xFF;
+  return [lsb, msb];
+};
+
+/**
+ * Converts a hex string (e.g., "A1 B2") to Uint8Array
+ */
+export const hexStringToBytes = (hex: string): Uint8Array | null => {
+  const cleanHex = hex.replace(/[\s-]/g, '');
+  if (cleanHex.length % 2 !== 0 || !/^[0-9A-Fa-f]+$/.test(cleanHex)) {
+    return null;
+  }
+  const bytes = new Uint8Array(cleanHex.length / 2);
+  for (let i = 0; i < cleanHex.length; i += 2) {
+    bytes[i / 2] = parseInt(cleanHex.substring(i, i + 2), 16);
+  }
+  return bytes;
+};
+
+/**
+ * Converts bytes to Hex String
+ */
+export const bytesToHexString = (bytes: Uint8Array | number[]): string => {
+  return Array.from(bytes)
+    .map(b => b.toString(16).padStart(2, '0').toUpperCase())
+    .join(' ');
+};
+
+/**
+ * Converts a hex string (with spaces) to ASCII string
+ */
+export const hexToAscii = (hex: string): string => {
+  if (!hex) return "";
+  const cleanHex = hex.replace(/[\s-]/g, '');
+  let str = "";
+  for (let i = 0; i < cleanHex.length; i += 2) {
+    const charCode = parseInt(cleanHex.substring(i, i + 2), 16);
+    // Replace non-printable characters with dots
+    if (charCode >= 32 && charCode <= 126) {
+      str += String.fromCharCode(charCode);
+    } else {
+      str += ".";
+    }
+  }
+  return str;
+};
+
+/**
+ * Converts an ASCII string to Hex string
+ */
+export const asciiToHex = (ascii: string): string => {
+  let hex = "";
+  for (let i = 0; i < ascii.length; i++) {
+    const code = ascii.charCodeAt(i);
+    hex += code.toString(16).padStart(2, "0").toUpperCase();
+  }
+  return hex;
+};