Choose your trigger mode — Mechanical vs Digital
The FarmBoard runs your machine through a four-step cycle on every print:
- Close door
- Open door + fan
- Bending
- Close door, return to idle
You can drive this cycle two ways. Digital mode is recommended for production — once it’s set up, every print runs the cycle automatically with no operator input. Mechanical mode is the always-available fallback and works without any network.
The two modes at a glance
Section titled “The two modes at a glance”| Mechanical | Digital (Full MQTT) | |
|---|---|---|
| Wi-Fi required | No | Yes |
| LAN-only mode required | No | Yes |
| Reliability | High | Very high |
You can switch between modes any time from the OTA page — both stay configured.
Mechanical mode
Section titled “Mechanical mode”The operator triggers each cycle step by pressing the limit switch on the machine. Works on every kit regardless of network connection, and is always available as a fallback even when Digital is enabled.
| Step | Gesture | What happens |
|---|---|---|
| 1. Close door | Long press (3-6 s) + short tap | Door closes, print can begin |
| 2. Open door + fan | Long press (4-8 s) at end of print | Door opens, fan starts cooling |
| 3. Start bending | Triple tap within 8 s | Fan off, bending cycle runs |
| 4. Close door + finish | Long press (4-8 s) | Door closes, returns to idle |
A few helpers on top of the four steps:
- Safety check (current sense): double-tap during the safety window
- Skip safety check: long press during the safety window
- Emergency reset: four quick taps within 10 s — homes the bender and returns to idle
Digital mode (Full MQTT)
Section titled “Digital mode (Full MQTT)”The FarmBoard talks directly to your Bambu Lab printer over Wi-Fi. The printer publishes its state in real time and the FarmBoard fires each step at the exact right moment — door close at print start, door open + fan at the last layer, bender after cooldown, door close on finish. No button presses.
What you need
Section titled “What you need”- The printer and the FarmBoard on the same Wi-Fi network.
- The printer set to LAN-only mode (Bambu Studio settings → Network → LAN Mode → on). Digital mode talks to the printer over the local MQTT broker, which is only exposed in LAN-only mode.
- Developer mode enabled on the printer (printer Settings → General → Developer Mode → on). Required for Bambu’s LAN MQTT access.
- Your print file processed by the FarmLoop app, version 2.7 or higher. The app renames the processed file with an
FL_S2_prefix and injects the silent timing markers the FarmBoard listens for. - Digital mode enabled on the FarmBoard’s OTA page, with your printer’s IP address and LAN access code entered.
Send the file the FarmLoop app produced as-is. Renaming or re-saving it (in Bambu Studio, your file browser, etc.) can strip the markers the FarmBoard relies on, and the cycle won’t fire. Re-process through the app if you need a new file.
- Enter OTA mode on the FarmBoard. The per-board gesture and web-UI access (
http://farmloop.local) live on the Firmware page → How to OTA update. - On the OTA page, fill in the Printer Connection card:
- Wi-Fi SSID + password (your home / shop network)
- Printer IP — printer Settings → Wi-Fi
- LAN access code — printer Settings → Network → LAN Mode (8 digits)
- Serial number — printer Settings → Device
- Tick Enable MQTT auto-trigger, click Save Printer Config, then Exit OTA Mode.
After reboot, the LED tells you what happened:
- 5 slow blinks + 10 fast blinks → Wi-Fi and MQTT both connected. You’re set.
- 2 long blinks → Wi-Fi failed; recheck SSID + password.
- 4 long blinks → MQTT failed; recheck the printer IP and LAN access code, and confirm LAN Mode is enabled on the printer.
Things to know
Section titled “Things to know”- The limit switch is disabled while Digital mode is connected, so an accidental press during a running print doesn’t interfere. To use the limit switch for testing or maintenance, turn Digital mode off on the OTA page or take the printer off the network.
- Local-only. MQTT runs on your LAN. Nothing leaves your network.
- Wi-Fi drop fallback. If the connection drops mid-print, the FarmBoard falls back to manual mode automatically. When the network returns, MQTT reconnects.
- Cancelled prints. Cancel from Bambu Studio or the printer screen and the FarmBoard opens the door and homes the bender automatically — no manual reset needed.
- “Stopped” in Bambu Studio. Bambu Studio sometimes labels a successful FarmLoop print as Stopped instead of Finished. That’s a display quirk in how it reads the gcode end. The FarmBoard completes its sequence correctly regardless.
Which should you use?
Section titled “Which should you use?”- Testing the kit, doing one-off prints, or your printer isn’t on Wi-Fi → Mechanical.
- Production, unattended runs → Digital. Set it up once; every
FL_S2_*file after that runs the full cycle automatically.
Next step
Section titled “Next step”With your trigger mode chosen, move on to Step 5, verify your installation.