SnapmakerU1-Extended-Firmware

RFID Filament Tag Support

The Snapmaker U1 can automatically detect filament properties (material type, color, temperatures) by reading RFID tags attached to filament spools.

The extended firmware adds support for NTAG tags with OpenSpool format, while maintaining compatibility with original Snapmaker tags.

• Original firmware: Mifare Classic 1K with Snapmaker format only
• Extended firmware: Adds NTAG215/216 support (OpenSpool format)

Supported Formats

Feature	OpenSpool 🏆	OpenPrintTag	OpenTag3D	Snapmaker
Tag Type	NTAG215 (540 bytes) / NTAG216 (888 bytes)	ISO15693/SLIX2	NTAG215/216 or ISO15693/SLIX2	Mifare Classic 1K
Encoding	JSON (NDEF)	CBOR (NDEF)	Binary	Proprietary + RSA signature
Data Format	Human-readable JSON	Compact CBOR binary	Binary	Encrypted proprietary
Specification	openspool.io	specs.openprinttag.org	OpenTag3D	Proprietary (closed)
GitHub Repository	spuder/OpenSpool	prusa3d/OpenPrintTag	queengooborg/OpenTag3D	N/A
Popularity	⭐⭐⭐ (623 stars)	⭐⭐ (213 stars)	⭐ (17 stars)	N/A
Programming Tools	Any NDEF-capable NFC app	Prusa app only	opentag3d.info/make	Snapmaker official only
U1 Compatible	✅ Yes (extended firmware)	❌ No (ISO15693 not supported)	⚠️ Not implemented yet	✅ Yes (all firmware)
Ease of Programming	Easy (any NFC app)	Medium (requires Prusa app)	Medium (web-based tool)	Hard (official tags only)
Data Portability	High (simple JSON)	High (open CBOR spec)	Medium (binary format)	None (proprietary)

🏆 = Recommended for U1 (NTAG215 is the sweet spot for capacity and compatibility)

How It Works

Tags Are Read When:

• Filament is loaded into the feeder
• Manually triggered via FILAMENT_DT_UPDATE CHANNEL=<n>
• On startup (if configured)

Tag Data Clears When:

• Filament is removed from the feeder
• Manually cleared via FILAMENT_DT_CLEAR CHANNEL=<n>

Programming Filament Tags

OpenSpool (Recommended)

1. Get NTAG215 or NTAG216 tags
2. Open Chrome on your Android phone
3. Go to printtag-web.pages.dev
4. Enter filament information
5. Tap tag to phone to write

Requirements: Android phone with NFC + Chrome browser

Alternatively, use any NFC app that supports NDEF with JSON. Set MIME type to application/json.

Example payload:

{
  "protocol": "openspool",
  "version": "1.0",
  "brand": "Generic",
  "type": "PLA",
  "color_hex": "#FF0000",
  "min_temp": 190,
  "max_temp": 220,
  "bed_min_temp": 50,
  "bed_max_temp": 60
}

Using the non-standard OpenSpool subtype field it is possible to specify a material subtype:

{
  "protocol": "openspool",
  "version": "1.0",
  "type": "PETG",
  "subtype": "Rapid",
  "color_hex": "AFAFAF",
  "brand": "Elegoo",
  "min_temp": "230",
  "max_temp": "260"
}

Supported OpenSpool Fields:

• protocol (required) - Must be “openspool”
• version (required) - Specification version (e.g., “1.0”)
• type (required) - Material type (e.g., “PLA”, “PETG”, “ABS”)
• color_hex (required) - Color in hex format (e.g., “#FF0000”)
• brand (optional) - Manufacturer name (e.g., “Generic”, “Overture”, “PolyLite”)
• min_temp (optional) - Minimum nozzle temperature in °C
• max_temp (optional) - Maximum nozzle temperature in °C
• bed_min_temp (optional) - Minimum bed temperature in °C
• bed_max_temp (optional) - Maximum bed temperature in °C

Supported non-standard OpenSpool Fields:

• subtype (optional, default: “Basic”) - Material subtype (e.g. “Rapid”, “HF”)

Snapmaker Orca Filament Naming Scheme

In order for Snapmaker Orca to recognize the filement, it must be named according to this naming scheme: <brand> <type> <subtype>, e.g. Generic PLA Basic and Elegoo PETG Rapid.

Reading Existing Tags

To check what’s on a tag before using it, use NFC Tools app (available on both iOS and Android):

1. Download NFC Tools from App Store (iOS) or Google Play (Android)
2. Open the app and tap “Read”
3. Hold your tag to the phone’s NFC reader
4. The app will show:
   • Tag type (NTAG213/215/216, Mifare Classic, ISO15693, etc.)
   • Memory size and available space
   • NDEF records (for OpenPrintTag/OpenSpool tags)
   • Raw data stored on the tag

What to look for:

• Tag Type: Should be NTAG213/215/216 or Mifare Classic 1K
• NDEF Message: For OpenSpool, look for MIME type application/json with OpenSpool payload

If the tag shows ISO15693, it’s an OpenPrintTag and won’t work with Snapmaker U1.

Common G-code Commands

# Check what tag detected
FILAMENT_DT_QUERY CHANNEL=0

# Force read tag
FILAMENT_DT_UPDATE CHANNEL=0

# Clear tag data
FILAMENT_DT_CLEAR CHANNEL=0

Troubleshooting

Tag not detected:

• Ensure tag is NTAG213/215/216 or Mifare Classic 1K
• Position tag close to reader antenna (1-3cm)
• Try manual update: FILAMENT_DT_UPDATE CHANNEL=<n> and then FILAMENT_DT_QUERY CHANNEL=<n>
• Look in klipper.log to see if tags were discovered

OpenPrintTag tags don’t work:

• Expected - OpenPrintTag uses ISO15693, Snapmaker uses ISO14443A
• Use NTAG with OpenSpool format instead

NTAG tags don’t work on original firmware:

• NTAG support is only in extended firmware
• Original firmware only reads Mifare Classic 1K with Snapmaker proprietary format

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