+// HITAG1 commands
+#define HITAG1_SET_CCNEW 0xC2 // left 5 bits only
+#define HITAG1_READ_ID 0x00 // not a real command, consists of 5 bits length, <length> bits partial SN, 8 bits CRC
+#define HITAG1_SELECT 0x00 // left 5 bits only, followed by 32 bits SN and 8 bits CRC
+#define HITAG1_WRPPAGE 0x80 // left 4 bits only, followed by 8 bits page and 8 bits CRC
+#define HITAG1_WRPBLK 0x90 // left 4 bits only, followed by 8 bits block and 8 bits CRC
+#define HITAG1_WRCPAGE 0xA0 // left 4 bits only, followed by 8 bits page or key information and 8 bits CRC
+#define HITAG1_WRCBLK 0xB0 // left 4 bits only, followed by 8 bits block and 8 bits CRC
+#define HITAG1_RDPPAGE 0xC0 // left 4 bits only, followed by 8 bits page and 8 bits CRC
+#define HITAG1_RDPBLK 0xD0 // left 4 bits only, followed by 8 bits block and 8 bits CRC
+#define HITAG1_RDCPAGE 0xE0 // left 4 bits only, followed by 8 bits page and 8 bits CRC
+#define HITAG1_RDCBLK 0xF0 // left 4 bits only, followed by 8 bits block and 8 bits CRC
+#define HITAG1_HALT 0x70 // left 4 bits only, followed by 8 bits (dummy) page and 8 bits CRC
+
+// HITAG2 commands
+#define HITAG2_START_AUTH 0xC0 // left 5 bits only
+#define HITAG2_READ_PAGE 0xC0 // page number in bits 5 to 3, page number inverted in bit 0 and following 2 bits
+#define HITAG2_READ_PAGE_INVERTED 0x44 // page number in bits 5 to 3, page number inverted in bit 0 and following 2 bits
+#define HITAG2_WRITE_PAGE 0x82 // page number in bits 5 to 3, page number inverted in bit 0 and following 2 bits
+#define HITAG2_HALT 0x00 // left 5 bits only