Custom Snapmaker U1 Firmware

External RFID Support

This document defines the external RFID integration contract for Snapmaker U1 Extended Firmware. For build and overlay workflow context, see Building from Source.

filament_detect Fields

The filament_detect object holds per-channel filament state in FILAMENT_INFO_STRUCT. The same field names are:

Writable fields:

Field Type Accepted values / format Notes
VENDOR string Any string  
MAIN_TYPE string PLA, PETG, ABS, TPU, PVA Other values accepted but not RFID-protocol-mapped
SUB_TYPE string Basic, Matte, SnapSpeed, Silk, Support, HF, 95A, 95A HF Other values accepted but not RFID-protocol-mapped
RGB_1 int Integer RGB value  
ALPHA int Integer 0..255  
HOTEND_MIN_TEMP int Integer  
HOTEND_MAX_TEMP int Integer  
BED_TEMP int Integer  
CARD_UID list[int] Array of byte ints  
SKU int Integer  

Read-only fields (returned by query, not accepted by set):

Field Notes
ARGB_COLOR Derived: (ALPHA << 24) \| RGB_1
OFFICIAL true when info is non-empty (set by firmware)
MANUFACTURER  
VERSION  
TRAY  
COLOR_NUMS  
RGB_2..RGB_5  
DIAMETER  
WEIGHT  
LENGTH  
DRYING_TEMP  
DRYING_TIME  
BED_TYPE  
FIRST_LAYER_TEMP  
OTHER_LAYER_TEMP  
MF_DATE  
RSA_KEY_VERSION  

API Contract: filament_detect/set

Endpoint:

Request shape:

{
  "channel": 0,
  "info": {
    "VENDOR": "Generic",
    "MAIN_TYPE": "PLA",
    "SUB_TYPE": "Basic",
    "RGB_1": 16737792,
    "ALPHA": 255,
    "HOTEND_MIN_TEMP": 200,
    "HOTEND_MAX_TEMP": 220,
    "BED_TEMP": 55,
    "CARD_UID": [161, 178, 195, 212],
    "SKU": 12345
  }
}
Field Required Type Accepted values
channel Yes int 0..3
info No object If missing/empty, treated as clear/reset

Response:

OpenSpool U1 Extended Format Input

This firmware uses an OpenSpool variant named OpenSpool U1 Extended Format.

Minimum payload:

{
  "protocol": "openspool",
  "type": "PLA",
  "color_hex": "#FF6600"
}

Extended payload:

{
  "protocol": "openspool",
  "version": "1.0",
  "brand": "Generic",
  "type": "PLA",
  "subtype": "Basic",
  "color_hex": "#FF6600",
  "additional_color_hexes": ["00FF00"],
  "alpha": 255,
  "min_temp": 200,
  "max_temp": 220,
  "bed_min_temp": 55,
  "bed_max_temp": 60,
  "diameter": 1.75,
  "weight": 1000
}

OpenSpool U1 Extended mapping profile:

OpenSpool field filament_detect/set.info print_task_config target Rule
brand VENDOR filament_vendor[channel] string passthrough
type MAIN_TYPE filament_type[channel] recommended uppercase
subtype SUB_TYPE filament_sub_type[channel] string passthrough
color_hex RGB_1 filament_color_rgba[channel] normalize to RRGGBB, convert to int; alpha appended later
alpha ALPHA filament_color_rgba[channel] int passthrough; combined with RGB_1 as RRGGBBAA
min_temp HOTEND_MIN_TEMP N/A stored in filament_detect only
max_temp HOTEND_MAX_TEMP N/A stored in filament_detect only
bed_min_temp/bed_max_temp BED_TEMP N/A collapsed to single bed temp
protocol N/A N/A parser validation only
version N/A N/A no endpoint field
additional_color_hexes N/A N/A no endpoint field; parser-only path supports extra colors
diameter N/A N/A no endpoint field
weight N/A N/A no endpoint field

Example

Source OpenSpool U1 Extended payload:

{
  "protocol": "openspool",
  "version": "1.0",
  "brand": "Generic",
  "type": "PLA",
  "subtype": "Basic",
  "color_hex": "#3366CC",
  "alpha": 128,
  "min_temp": 205,
  "max_temp": 225,
  "bed_min_temp": 55,
  "bed_max_temp": 60
}

Call 1 (external bridge/client transformation and write):

curl -s http://<host>/printer/filament_detect/set \
  -H 'Content-Type: application/json' \
  -d '{
    "channel": 0,
    "info": {
      "VENDOR": "Generic",
      "MAIN_TYPE": "PLA",
      "SUB_TYPE": "Basic",
      "RGB_1": 3368652,
      "ALPHA": 128,
      "HOTEND_MIN_TEMP": 205,
      "HOTEND_MAX_TEMP": 225,
      "BED_TEMP": 55
    }
  }'

Call 1 response:

{
  "state": "success"
}

Call 2 (read filament_detect):

curl -s 'http://<host>/printer/objects/query?filament_detect'

Call 2 response (relevant subset):

{
  "result": {
    "status": {
      "filament_detect": {
        "info": [
          {
            "VENDOR": "Generic",
            "MAIN_TYPE": "PLA",
            "SUB_TYPE": "Basic",
            "RGB_1": 3368652,
            "ALPHA": 128,
            "ARGB_COLOR": 2150852300,
            "HOTEND_MIN_TEMP": 205,
            "HOTEND_MAX_TEMP": 225,
            "BED_TEMP": 55,
            "OFFICIAL": true
          }
        ]
      }
    }
  }
}

Call 3 (read print_task_config):

curl -s 'http://<host>/printer/objects/query?print_task_config'

Call 3 response (relevant subset):

{
  "result": {
    "status": {
      "print_task_config": {
        "filament_vendor": ["Generic"],
        "filament_type": ["PLA"],
        "filament_sub_type": ["Basic"],
        "filament_color_rgba": ["3366CC80"],
        "filament_official": [true]
      }
    }
  }
}

Transformation trace for this example:

Source Transformed value Target field
brand = "Generic" VENDOR = "Generic" filament_detect.info[0].VENDOR
type = "PLA" MAIN_TYPE = "PLA" filament_detect.info[0].MAIN_TYPE
subtype = "Basic" SUB_TYPE = "Basic" filament_detect.info[0].SUB_TYPE
color_hex = "#3366CC" RGB_1 = 3368652 filament_detect.info[0].RGB_1 = 3368652
alpha = 128 ALPHA = 128 filament_detect.info[0].ALPHA = 128
derived ARGB_COLOR = (0x80 << 24) \| 0x3366CC filament_detect.info[0].ARGB_COLOR = 2150852300
min_temp = 205 HOTEND_MIN_TEMP = 205 filament_detect.info[0].HOTEND_MIN_TEMP
max_temp = 225 HOTEND_MAX_TEMP = 225 filament_detect.info[0].HOTEND_MAX_TEMP
bed_min_temp = 55, bed_max_temp = 60 BED_TEMP = 55 filament_detect.info[0].BED_TEMP
OFFICIAL rule non-empty info filament_detect.info[0].OFFICIAL = true
RGB_1 + ALPHA 3366CC80 print_task_config.filament_color_rgba[0]
mirrored identity Generic PLA Basic print_task_config.filament_vendor/type/sub_type[0]

References

Repository overlays:

Klipper source code:

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