Write BYTES to MIFARE without trancoding to ASCII-HEX

Projects Programming
6

Hi,

I figured it out partly:

//example code:
String input = "d73f7a79";

byte string_chunk_bytes[9];
input.getBytes(string_chunk_bytes, 9);

status = mfrc522.MIFARE_Ultralight_Write(i, string_chunk_bytes, 8);

the last line sends the data to the MIFARE chip.
The code above is just a simple example. In reality there are more strings that are separated in "chunks" of 8 characters (-> "d73f7a79").
Via for-loop "string_chunk_bytes" is generated several times and sent to different address pages of the chip.
Long story short: the output of strin_chunk_bytes:

11b701e0
bdb8b0d7
76f2c520
c9748ade
57c1be9a
.
.
.

and the result, when I read the newly written data of the chip (Page 6 to 15):

Firmware Version: 0x92 = v2.0
Scan PICC to see UID, SAK, type, and data blocks...
Card UID: 04 93 D4 12 5F 70 80
Card SAK: 00
PICC type: MIFARE Ultralight or Ultralight C
Page  0  1  2  3
  0   04 93 D4 CB
  1   12 5F 70 80
  2   BD 48 00 00
  3   E1 10 3E 00
  4   03 00 FE 00
  5   00 00 00 00
  6   31 31 62 37
  7   62 64 62 38
  8   37 36 66 32
  9   63 39 37 34
 10   35 37 63 31
.
.
.

As you can see, MFRC522 changes "my" bytes (e.g. the first pair: 11) to ASCII-hex 31 and 31...
"my" "b" changes to "62" and so on...

Is there a way to send the data "unchanged" to the chip?
Desired result:

Firmware Version: 0x92 = v2.0
Scan PICC to see UID, SAK, type, and data blocks...
Card UID: 04 93 D4 12 5F 70 80
Card SAK: 00
PICC type: MIFARE Ultralight or Ultralight C
Page  0  1  2  3
  0   04 93 D4 CB
  1   12 5F 70 80
  2   BD 48 00 00
  3   E1 10 3E 00
  4   03 00 FE 00
  5   00 00 00 00
  6   11 B7 01 E0
  7   BD B8 B0 D7
  8   76 F2 C5 20
  9   C9 74 8A DE
 10   57 C1 BE 9A
.
.
.

Thank you so much!