Custom Snapmaker U1 Firmware

RFID Format & Reader Design

The Snapmaker U1 automatically detects filament properties by reading RFID tags on spools. Tags are read when filament is loaded into the feeder, and the data clears when filament is removed.

Firmware Support:

• Original: Mifare Classic 1K with Snapmaker proprietary format
• Extended: Supports Custom Tags via OpenSpool, OpenRFID, or External Readers

For the OpenSpool payload format and field reference, see OpenSpool Format Design.

Readers

What each detection system or hardware reader can identify.

Notes:

• SpoolLink means the reader reports a tag’s UID to the printer even when it can’t parse the tag’s contents (unknown format, encrypted, or blank), so the spool can still be resolved by SpoolLink UID linking.
• Bambu and Creality require providing encryption keys (see Bambu / Creality Spool Configuration below).
• External readers sit outside the printer — for example on a drybox — and push tags to the U1 over the network. To use one, set the RFID Detection System to External. Licences: wasikuss MIT, baze CC BY-NC 4.0.

Apps

Community apps that create and write filament tags. The quickest way to write a tag is PrintTag-Web: open it in Chrome on Android, enter the filament details, and tap an NTAG215/216 tag to the phone. Any app that writes NDEF with JSON (MIME type application/json) also works.

App	Author	Platform	Reads	Writes	Vendor Tags	Source	Support
U1-RFID	DnG-Crafts	Android (Google Play)	OpenSpool	OpenSpool, including all U1 extended fields	–	GitHub (source)	—
SpoolPainter	ni4223	Android (Google Play)	OpenSpool	OpenSpool	Bambu, Snapmaker, QIDI, Anycubic, Elegoo, Creality	GitHub (GPL-3.0)
SpoolKid	Marco	iOS (TestFlight beta; build from source)	OpenSpool, OpenTag3D, ELEGOO, Anycubic ACE; UID-only for Mifare Classic and unrecognized tags	OpenSpool, OpenTag3D, ELEGOO, Anycubic ACE	ELEGOO, Anycubic ACE	GitHub (MIT)
OpenSpool app	spuder	Android, iOS	OpenSpool (basic fields)	OpenSpool (basic fields)	–	GitHub (source)
PrintTag-Web	paxx12	Android (Chrome, Web NFC)	OpenSpool, OpenPrintTag	OpenSpool, OpenPrintTag	–	GitHub (source)
NFC Tools	wakdev	Android (Google Play), iOS (App Store)	Any NDEF	Any NDEF	–	Closed source	—
TigerTag Studio Manager	TigerSystem	Windows, macOS, Linux (desktop, ACR122U USB NFC reader recommended)	TigerTag	TigerTag	–	GitHub (MIT)	—
TigerTag Connect	TigerSystem	Android (Google Play), iOS (App Store)	TigerTag	TigerTag	–	Closed source	—

Notes:

• Custom tags are only readable by the U1 on extended firmware.
• PrintTag-Web requires Chrome on Android (Web NFC API); it cannot read or write tags on iOS, desktop Chrome, or other browsers.
• Use NFC Tools to inspect an existing tag’s type and NDEF records.
• Apps that also link tags to Spoolman spools are listed in Spoolman Integration.

Enabling OpenRFID

The OpenRFID detection system is an alternative to Snapmaker’s built-in filament tag detection, based on the OpenRFID project. It adds support for tagged spools from multiple manufacturers.

To enable it, navigate to the firmware-config web interface, go to Snapmaker Components > RFID Detection System, and select OpenRFID or OpenRFID (force generic vendor).

• OpenRFID - Filament is identified by brand and type. Spools unrecognized by Snapmaker Orca are hidden in Snapmaker Orca.
• OpenRFID (force generic vendor) - Same as OpenRFID, but spools are labeled as Generic so they always appear in Snapmaker Orca.
• External - Disables the built-in readers entirely, useful for external readers.

Bambu / Creality Spool Configuration

Bambu and Creality tagged spools require authentication keys. Add them to the OpenRFID user configuration file:

/oem/printer_data/config/extended/openrfid_user.cfg

For Bambu spools:

[bambu_lab_tag_processor]
key = <your 32 hex character key>

For Creality spools:

[creality_tag_processor]
key = <your 32 hex character key>
encryption_key = <your 32 hex character key>

After editing, restart the printer.

Enabling Disabled By Default Tag Systems

Some tag formats are disabled by default, for example as they do not read reliably. Enable them in /oem/printer_data/config/extended/openrfid_user.cfg by removing the # prefix from the tag processor:

# [elegoo_tag_processor]

SpoolEase tags (NTAG NDEF) are also supported but not enabled by default. Add the processor to the same file to use them:

[spoolease_tag_processor]

Manual Commands

• Read tag: FILAMENT_DT_UPDATE CHANNEL=<n>
• Clear tag data: FILAMENT_DT_CLEAR CHANNEL=<n>
• Check current tag: FILAMENT_DT_QUERY CHANNEL=<n>

Troubleshooting

Tag not detected:

• Ensure tag is NTAG213/215/216 or Mifare Classic 1K — ISO15693 tags (OpenPrintTag) are not supported by the U1 hardware
• Position tag within 1-3cm of reader antenna
• Ensure you place on tag on the side next to the U1 housing, which will depend on which side of the printer you load the spool
• If a vendor tag is present, for example Bambu Lab filament tags, this will usually interfere with reading a user-provided tag (you can cover up the vendor tag with foil tape)
• Manually read tag: FILAMENT_DT_UPDATE CHANNEL=<n> then FILAMENT_DT_QUERY CHANNEL=<n>
• For OpenRFID issues, open Fluidd Logs and fetch openrfid.log

NTAG tags not read:

• NTAG215/216 support requires extended firmware; original firmware only supports Mifare Classic 1K with the Snapmaker proprietary format