ACR122L – Communication Protocol
Version 1.03
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Page 47 of 57
6.18.2. Accessing Mifare Ultralight tags
Typical sequence may be:
1. Scanning the tags in the field (Polling).
2. Read/Write the memory of the tag.
3. Halt the tag (optional).
Step 1. Polling for the MIFARE Ultralight Tags, 106 kbps.
HOST -> 02 6F 09 00 00 00 00 01 00 00 00
HOST -> FF 00 00 00 04 D4 4A
01 00
[Checksum] 03
RDR -> 02 00 00 03 (Waiting the Tag)
RDR -> 02 80 11 00 00 00 00 01 01 00 00
RDR -> D5 4B
01
01
00 44
00
07
04 6E 0C A1 BF 02 84
90 00 [Checksum] 03
In which,
Number of Tag found = [01];
Target number = 01
SENS_RES = 00 44;
SEL_RES = 00
,
Length of the UID = 7;
UID = 04 6E 0C A1 BF 02 84
Operation Finished = 90 00
Step 2. Read the content of Page
04
.
HOST -> 02 6F 0A 00 00 00 00 01 00 00 00
HOST -> FF 00 00 00 05 D4 40
01
30
04
[Checksum] 03
RDR -> 02 00 00 03 (Waiting the Tag)
RDR -> 02 80 15 00 00 00 00 01 01 00 00
RDR -> D5 41 [00]
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
90 00 [Checksum] 03
In which, Block Data =
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
Note:
4 consecutive Pages will be retrieved. Pages 4, 5, 6 and 7 will be retrieved. Each data page
consists of 4 bytes.
Step 3. Update the content of Page
04
with
the data “AA BB CC DD”
.
HOST -> 02 6F 0E 00 00 00 00 01 00 00 00
HOST -> FF 00 00 00 09 D4 40
01
A2
04
AA BB CC DD
[Checksum] 03
RDR -> 02 00 00 03 (Waiting the Tag)
RDR -> 02 80 05 00 00 00 00 01 01 00 00
RDR -> D5 41 [00] 90 00 [Checksum] 03
OR
