Connect your print farm to Home Assistant.

What you can do with it

• Air filter for ABS and ASA. The enclosure fan comes on when a fume-heavy print starts and goes off 15 minutes after it ends.
• Power off when done. A smart plug cuts power once the printer has cooled.
• Hear about failures. The shop lights flash red and a speaker says which printer failed.
• Plate reminders. A speaker says "Clear the plate on H2D-1" when the queue needs you.
• Light for the camera. A lamp turns on while a printer is printing.

Google Home and Alexa speakers work too, through Home Assistant.

The events Layers3D sends

Event	When
print.started	A printer starts a print
print.completed	A print finishes
print.failed	A print fails on its own
print.stopped	Someone stops a print
printer.error	A new printer alert
plate.clear_needed	A queue print is done and the bed needs clearing
printer.queue_paused	The print queue puts a hold on a printer
filament.low	A spool drops below your low mark

Each one carries printer (the name you gave it in Layers3D), job, order_number, material, vent (true for ABS, ASA, PC, nylon and other fume-heavy materials), minutes_left on a start, progress and error on a failure, and a link back to Layers3D.

Step 1: a relay automation in Home Assistant

This one automation receives everything from Layers3D and passes it on as a Home Assistant event called layers3d_printer. Every other automation listens for that event, so you set up the address once.

In Home Assistant go to Settings › Automations & scenes › Create automation › Create new automation, open the ⋮ menu, choose Edit in YAML and paste this. Change the webhook_id to something long and random: it works like a password.

alias: Layers3D relay
triggers:
  - trigger: webhook
    webhook_id: layers3d-change-me-to-something-long-and-random
    allowed_methods: [POST]
    local_only: false
actions:
  - event: layers3d_printer
    event_data:
      event: "{{ trigger.json.event }}"
      printer: "{{ trigger.json.data.printer }}"
      job: "{{ trigger.json.data.job }}"
      order_number: "{{ trigger.json.data.order_number }}"
      material: "{{ trigger.json.data.material }}"
      vent: "{{ trigger.json.data.vent }}"
      minutes_left: "{{ trigger.json.data.minutes_left }}"
      progress: "{{ trigger.json.data.progress }}"
      error: "{{ trigger.json.data.error }}"
      link: "{{ trigger.json.data.link }}"
mode: queued

Step 2: get the address

Layers3D runs on the internet, so Home Assistant has to be reachable from the internet.

• With Home Assistant Cloud: go to Settings › Home Assistant Cloud, find Webhooks, and turn on the one for "Layers3D relay". Copy the https://hooks.nabu.casa/… address it shows.
• Without it: the address is https://your-home-assistant-address/api/webhook/ followed by your webhook_id. An address like 192.168.1.20 only works inside your building, so it won't work here.

Step 3: add it in Layers3D

In Layers3D go to Settings › Data › Send events out › Add a webhook. Paste the address, leave Send as on Detect from the address, tick the events under Printers, and press Add webhook. Press Send test on the new row: Home Assistant's automation trace should show a run.

Ready automations

Paste each one the same way as step 1. Change the printer name and the entity_ids to yours.

Air filter for ABS and ASA

alias: H2D-1 air filter for ABS/ASA
mode: restart
triggers:
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.started, printer: H2D-1 }
    id: start
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.completed, printer: H2D-1 }
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.failed, printer: H2D-1 }
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.stopped, printer: H2D-1 }
actions:
  - choose:
      - conditions:
          - condition: trigger
            id: start
          - condition: template
            value_template: "{{ trigger.event.data.vent | bool }}"
        sequence:
          - action: switch.turn_on
            target: { entity_id: switch.h2d_1_air_filter }
      - conditions:
          - condition: trigger
            id: start
        sequence:
          - action: switch.turn_off
            target: { entity_id: switch.h2d_1_air_filter }
    default:
      - delay: "00:15:00"
      - action: switch.turn_off
        target: { entity_id: switch.h2d_1_air_filter }

Smart plug off when a print is done

Waits 20 minutes so the nozzle and bed cool, and does nothing if another print starts in that time. Don't use it on a printer that takes print queue jobs: the queue can't send to a printer that's off.

alias: H2S-2 power off after printing
mode: restart
triggers:
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.completed, printer: H2S-2 }
    id: done
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.started, printer: H2S-2 }
actions:
  - condition: trigger
    id: done
  - delay: "00:20:00"
  - action: switch.turn_off
    target: { entity_id: switch.h2s_2_plug }

Flash the lights and say it when a print fails

alias: Print failed alert
triggers:
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.failed }
actions:
  - action: light.turn_on
    target: { entity_id: light.print_room }
    data: { color_name: red, flash: long }
  - action: tts.speak
    target: { entity_id: tts.google_translate_en_com }
    data:
      media_player_entity_id: media_player.shop_speaker
      message: "Print failed on {{ trigger.event.data.printer }}"

Say when a plate needs clearing

alias: Plate to clear
triggers:
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: plate.clear_needed }
actions:
  - action: tts.speak
    target: { entity_id: tts.google_translate_en_com }
    data:
      media_player_entity_id: media_player.shop_speaker
      message: "Clear the plate on {{ trigger.event.data.printer }}"

Camera light while printing

alias: X2D-1 camera light
mode: restart
triggers:
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.started, printer: X2D-1 }
    id: start
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.completed, printer: X2D-1 }
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.failed, printer: X2D-1 }
  - trigger: event
    event_type: layers3d_printer
    event_data: { event: print.stopped, printer: X2D-1 }
actions:
  - if:
      - condition: trigger
        id: start
    then:
      - action: light.turn_on
        target: { entity_id: light.x2d_1_lamp }
    else:
      - action: light.turn_off
        target: { entity_id: light.x2d_1_lamp }

What Home Assistant can't do

It can't start a print. Starting stays in Layers3D, where the plate checks are, so a plate that wasn't cleared never gets a new print on top of it.