nfc.txt

N.B. Quoted strings are NOT NUL-terminated unless otherwise noted.
Useful reading: https://www.nxp.com/docs/en/data-sheet/MF1S50YYX_V1.pdf

(AiMe branded cards are Mifare Classic cards. Other technologies exist though)

Summary
-------

Hardware:
    Assembly connector:
        5V Host in
        Tx;Rx;GND Host RS232 in
        Tx;Rx;GND Daisy-chain out
    Main board (probably LED controller):
        Silk "837-15084"
        CN1: Host 5V power in, ?V NFC-sub power out
        CN2: Host RS232 Tx;Rx;GND in, NFC-sub Tx;Rx out
        CN3: LED-Sub power and data(?) out
        DIPSW1: Set to hex nibble 8.
        Contains ADM3222 RS232 transceiver IC
        Contains ATMega32 MCU
    NFC subboard:
        Sticker: Model "TN32MSEC003S"
        CN1: ?V power and Tx;Rx;GND in, Tx;Rx;GND ass'y CN daisy out.
        DIPSW1: Set to hex nibble 0.
        Contains ATmega168 MCU
        Contains ADM3202A RS232 transceiver IC
        Contains shielded RF circuit
        Entire non-ground-plane PCB area is visible through the chassis
        torx screws lol
    LED subboard:
        Silk: "837-15120"
        CN1: ?V power and Tx;Rx;GND in.
        Five RGB LEDs and a bunch of resistors
        No visible logic ICs..?
        No DIPSW.

JVS framing:
    E0 sync
    D0 escape (+1 to unescape)
    Checksum is sum of bytes after unescaping

Frame header:
    Frame length (including length byte itself)
    Address
    Sequence no, hopefully loops before hitting esc byte...
    Command byte

Bus addressing:
    Low nibble set using DIPSWs
    High nibble ???
    Daisy chaining mechanism unknown (RS232 wires probably multi-tap)

Startup
-------

Addr 00 Command 62:
    Req:
        00  Payload length
    Resp:
        00  Status byte
        00  Payload length
    Description:
        Unknown. Reset?

Addr 00 Command 30:
    Req:
        00  Payload length
    Resp:
        00  Status byte
        17  Payload length
        ..  "TN32MSEC003S F/W Ver1.2E"
    Description:
        Get firmware version

Addr 00 Command 32:
    Req:
        00  Payload length
    Resp:
        00  Status byte
        17  Payload length
        ..  "TN32MSEC003S H/W Ver3.0J"
    Description:
        Get hardware version

Addr 08 Command f5:
    Req:
        00  Payload length
    Resp:
        00  Status byte
        00  Payload length
    Description:
        LED sub-board reset.
        Won't accept LED commands until you do this.

Addr 08 Command f0:
    Req:
        00  Payload length
    Resp:
        00  Status byte
        09  Payload length
        ..  "15084" (part nr for LED board)
        FF  ??
        11  ??
        00  ??
        12  ??
    Description:
        Get board "info"

Addr 00 Command 54:
    Req:
        06  Payload length
        57  'W'
        43  'C'
        43  'C'
        46  'F'
        76  'v'
        32  '2'
    Resp:
        00  Status byte?
        00  ??
    Description:
        Set Mifare KeyA.
        "WCCF" might refer this this SEGA arcade game:
        https://en.wikipedia.org/wiki/World_Club_Champion_Football
        It's quite old and has AiMe readers, maybe where they first appeared?

Addr 00 Command 50:
    Req:
        06  Payload length
        60  ??
        90  ??
        D0  ?? (This is escaped of course)
        06  ??
        32  ??
        F5  ??
    Resp:
        00  Status byte
        00  Payload length
    Description:
        Possibly Mifare KeyB.

Polling
-------

Addr 00 Command 40:
    Req:
        01  Payload length
        03  ??
    Resp:
        00  Status byte
        00  Payload length
    Description:
        Poll some other NFC technology?

Addr 00 Command 42:
    Req:
        00  Payload length
    Resp if no MiFare card:
        00  Status byte
        01  Payload length
        00  (represents nothing i guess)
    Resp if MiFare card:
        00  Status byte?
        07  Payload length
                01  Chunk length?
                10  ?? Block size maybe?
                04  Chunk length?
                ..  Mifare UID, four bytes.
    Description:
        Check for Mifare card presence?

Addr 00 Command 41:
    Req:
        00  Payload length
    Resp:
        00  Status byte
        00  Payload length
    Description:
        Unknown. Poll some other NFC technology?

Card read
---------

Addr 00 Command 43:
    Req:
        04  Payload length
        ..  Mifare UID, four bytes.
    Resp:
        00  Status byte
        00  Payload length
    Description:
        Select MiFare by UID?

Addr 00 Command 55:
    Req:
        05  Payload length
        ..  Mifare UID, four bytes.
        03  ??
    Resp:
        00  Status byte
        00  Payload length
    Description:
        Unknown.
        Block 3 on a Mifare sector contains keys and an access control list.
        It is generally not accessed directly (unless being provisioned?)

Addr 00 Command 52:
    Req:
        05  Payload length
        ..  Mifare UID, four bytes.
        ..  Block number, 1 or 2.
    Resp for Block 1:
        00  Status byte
        10  Payload length (1 block)
        ..  "SBSD"
            00 00 00 00
            00 00 00 00
            00 4E C6 22
    Resp for Block 2:
        00  Status byte
        10  Payload length (1 block)
        ..  00 00 00 00 00 00 xx xx
            xx xx xx xx xx xx xx xx
    Description:
        Probably reads blocks 1 and 2 from Mifare sector 0.
        Block 0 contains the "vendor information" and UID.
        Block 1 contents are unknown, probably AiMe DB info.
        Block 2 last 10 bytes hex are printed on the card ("local unique id").
        (Block 3 contains encryption keys so is not allowed to be read)

LED
---

Addr 08 Command 81:
    Req:
        03  Payload length
        ff  Red intensity
        ff  Green intensity
        ff  Blue intensity
    Resp:
        None! Command is not acknowledged
    Description:
        Set LED color