feat: NFC tag spool_id for Spoolman integration

[joostliebregts]

Summary

Thanks for building the extended firmware - it's made the U1 so much more usable.

I added an optional spool_id field to the OpenSpool parsing so users with Spoolman can get automatic spool tracking when they load filament. Tags without spool_id still work exactly as before.

Changes

• filament_protocol_ndef.py: Extract optional spool_id field from OpenSpool JSON into info['SPOOL_ID']
• 02-add-ndef-protocol.patch: Call ON_NFC_SPOOL_READ CHANNEL=<n> SPOOL_ID=<id> macro when spool_id is present
• docs/rfid_support.md: Add Spoolman Integration section with field reference and example macro
• examples/nfc_spoolman.cfg: Ready-to-use macro file users can copy to their config

Tag Format

Users add spool_id to their existing OpenSpool tags:

{
  "protocol": "openspool",
  "version": "1.0",
  "brand": "Elegoo",
  "type": "PLA",
  "color_hex": "#FF5733",
  "spool_id": 42
}

Backward Compatibility

• Tags without spool_id work exactly as before
• The macro call only fires when spool_id is present
• No configuration required unless user wants Spoolman integration

Example Macro

Users create extended/klipper/nfc_spoolman.cfg:

[gcode_macro ON_NFC_SPOOL_READ]
gcode:
    {% set channel = params.CHANNEL|int %}
    {% set spool_id = params.SPOOL_ID|int %}
    {% set tool = "T" ~ channel %}
    SET_GCODE_VARIABLE MACRO={tool} VARIABLE=spool_id VALUE={spool_id}
    RESPOND PREFIX="NFC" MSG="Spool {spool_id} assigned to {tool}"

Testing

• Tested with NTAG215 tags containing OpenSpool JSON with spool_id field
• Verified backward compatibility with tags without spool_id
• Verified macro is called with correct channel and spool_id parameters

[joostliebregts]

Not entirely sure, but I believe this implementation has more 'read nfc and spoolman' features built in. #163

[unlucio]

Not entirely sure, but I believe this implementation has more 'read nfc and spoolman' features built in. #163

Indeed.
Setting the spool is a start, but to achieve accuracy, the tool map needs to be taken into account; otherwise, it will track the wrong spool for every situation where the G-code's T-number does not match the physical one.

[unlucio]

https://en.wikipedia.org/wiki/Separation_of_concerns
This is probably not the place to deal with this.

[joostliebregts]

Cool that you picked up on that! Do you have software development experience? Seems like you know what you're doing. Whereas I am trusting the magnificent Opus 😄 I appreciate you taking a look and letting me know!

[unlucio]

Cool that you picked up on that! Do you have software development experience? Seems like you know what you're doing. Whereas I am trusting the magnificent Opus 😄 I appreciate you taking a look and letting me know!

I might have a bit of experience in the SW/IT field, and pondered this "problem" and its solution for a bit before implementing it 😄
I have no idea what Opus is

[joostliebregts]

Ah, with Opus I refer to the almighty Claude Opus 4.5. The state of the art AI model from Anthropic.