FarmLoop firmware

Firmware runs on the FarmBoard control board inside your FarmLoop module. It handles the bending routine, limit-switch gestures, door control (P/X and H series), and MQTT communication with your Bambu printer.

There are two ways to update:

1. USB-C flash from your browser (recommended for major versions), plug the controller board into your computer with a USB-C cable and click the button below. Works in Chrome and Edge. Erases and re-flashes the full firmware.
2. OTA update via the board’s web page (for small updates), enter OTA mode on the running board, open its web UI, and upload the _OTA.bin file. No cable needed.

If you’re not sure which firmware you need, check the printer model and the FarmBoard revision printed on your control board - each FarmBoard generation has its own firmware binary and they cannot be swapped.

Current firmware

Bambu A Series

Bambu A1 Mini, A1

v1.50 July 2026

Release notes

• Digital Mode (Full MQTT) released: all triggers run automatically from the print’s G-code markers.
• Requires G-code processed with the FarmLoop App 2.71 or higher.

FarmBoard 1

Download OTA .bin · FB1

⚡ USB-C flash v1.50 · FB1USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

FarmBoard 2

Download OTA .bin · FB2

⚡ USB-C flash v1.50 · FB2USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

Bambu P/X Series

Bambu P1P, P1S, P2S, X1C, X2D

v2.94 July 2026

Release notes

• Digital Mode (Full MQTT) released: all triggers run automatically from the print’s G-code markers.
• Multi-loop prints fixed: in some cases the first loop ran fine but the following loops did not trigger.
• Serial number entry is case-insensitive - lowercase input is corrected automatically.

Download OTA .bin ⚡ USB-C flash v2.94 USB-C flash (Chrome / Edge only) USB-C flash needs HTTPS

Bambu H Series

Bambu H2S, H2D, H2C

v3.10 July 2026

Release notes

• Digital Mode (Full MQTT) released: all triggers run automatically from the print’s G-code markers.
• Multi-loop prints fixed: in some cases the first loop ran fine but the following loops did not trigger.
• Serial number entry is case-insensitive - lowercase input is corrected automatically.

FarmBoard 3

FarmBoard 3 needs to be powered via the AMS plug before USB-C flashing - the USB-C port alone doesn’t power the chip.

Download OTA .bin · FB3

⚡ USB-C flash v3.10 · FB3USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

FarmBoard 2

Download OTA .bin · FB2

⚡ USB-C flash v3.10 · FB2USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

Which FarmBoard build do I need?

The A series and H series each ship with one of two boards. Check the silkscreen on your FarmBoard and use the matching tab:

• A series - FarmBoard 1 (ESP32-C3, original boards) or FarmBoard 2 (ESP32-S3, newer boards).
• H series - FarmBoard 2 (earlier kits) or FarmBoard 3 (later kits, both ESP32-S3).

If you can’t tell, the newer board is usually the right call (FB 2 for A series, FB 3 for H series) - flashing fails harmlessly if the wrong build is used, and you can switch tabs and try the other.

Previous versions

Older firmware is published here so you can roll back if a newer release misbehaves on your setup. Either USB-C flash with the button on the card, or enter OTA mode on the running board and upload the _OTA.bin via its Firmware Update page.

• A series: roll back from v1.50 to v1.40, or all the way to the v1.30 shipping firmware.
• P/X series: roll back from v2.94 to v2.92. (v2.93 is intentionally not offered - it has known multi-loop trigger bugs that v2.94 fixes.)
• H series: roll back from v3.1 to v3.00.

Bambu A Series

Bambu A1 Mini, A1

v1.40 April 2026

Release notes

• Startup procedure that tests actuators and fan
• Manual triggering only (long-press / triple-tap) - no MQTT

FarmBoard 1

Download OTA .bin · FB1

⚡ USB-C flash v1.40 · FB1USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

FarmBoard 2

Download OTA .bin · FB2

⚡ USB-C flash v1.40 · FB2USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

Bambu A Series

Bambu A1 Mini, A1

v1.30 Shipping firmware

Release notes

• Original shipping firmware, most A-series boards left the factory with this build
• v1.30 itself has no OTA web page, to come back up to v1.40 (or later) you must USB-C flash
• The “Download OTA .bin” button below is only for going to v1.30, by uploading it from a board already on v1.40

Download OTA .bin ⚡ USB-C flash v1.30 USB-C flash (Chrome / Edge only) USB-C flash needs HTTPS

Bambu P/X Series

Bambu P1P, P1S, P2S, X1C

v2.92 April 2026

Release notes

• Fixed OTA Wi-Fi bug that froze the PCB after setting Wi-Fi credentials
• Improved trigger reliability and stability
• MQTT Trigger option added (enable / disable via OTA page)

Download OTA .bin ⚡ USB-C flash v2.92 USB-C flash (Chrome / Edge only) USB-C flash needs HTTPS

Bambu H Series

Bambu H2S, H2D, H2C

v3.00 June 2026

Release notes

• Previous H-series release - MQTT triggering armed per cycle via the 4-tap reset

FarmBoard 3

FarmBoard 3 needs to be powered via the AMS plug before USB-C flashing - the USB-C port alone doesn’t power the chip.

Download OTA .bin · FB3

⚡ USB-C flash v3.00 · FB3USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

FarmBoard 2

Download OTA .bin · FB2

⚡ USB-C flash v3.00 · FB2USB-C flash (Chrome / Edge only)USB-C flash needs HTTPS

How to USB-C flash

1. Power off your printer and unplug the controller board from AMS / 5V power.
2. Plug a USB-C cable from your computer into the controller board’s USB-C port.
3. Click “USB-C flash” in the card above for your printer family.
4. Select the serial port Chrome / Edge shows for the board. It’s usually named USB-SERIAL, CH340, CP210x, or USB JTAG/serial debug unit.
5. Click Install. The browser erases the chip and writes the new firmware. This takes 30-60 seconds.
6. When done, unplug USB-C, reconnect AMS / 5V power, and verify the LED startup sequence (see below).

Browser support

USB-C flashing uses the Web Serial API, which is only available in Chrome and Edge on desktop. Safari and Firefox don’t support it. On mobile, use OTA instead.

Driver for CH340 / CP210x on older setups

Most recent Windows and macOS installs ship with the USB-to-serial driver already. If the browser can’t see the port, install the CH340 (from WCH) or CP210x (from Silicon Labs) driver and re-plug the cable.

How to OTA update

1. Download the _OTA.bin file for your printer family (the “Download OTA .bin” button in the cards above).
2. Enter OTA mode and open the board’s web page - 5 quick taps on the LIMIT SWITCH (A series) or the DOOR BUTTON (P/X and H series), join the FarmLoop Wi-Fi, then open farmloop.local.
3. Scroll to the Firmware Update card, pick the _OTA.bin file, and click Upload.
4. The board reboots automatically after a successful upload.

5-minute timeout

OTA mode times out after 5 minutes and the board reboots. Save changes before then.

Getting logs from the FarmBoard

If you’re reporting a firmware problem, the board’s log is the single most useful thing you can send us - it captures boot reasons, Wi-Fi/MQTT status, and the full trigger sequence. The log lives on the same web page you use for OTA updates.

1. Enter OTA mode and open the board’s web page - 5 quick taps on the LIMIT SWITCH (A series) or the DOOR BUTTON (P/X and H series), join the FarmLoop Wi-Fi network (password 3D-Farmers), then open farmloop.local (or 192.168.4.1).
2. Scroll to the Live Serial card.
3. Click Download .txt (highlighted below). Your browser saves a farmloop_log.txt file.
4. Attach that file to a support ticket under Technical issue, along with the .gcode.3mf of any print that triggered the problem.

Tip

Download the log soon after the problem happens - the board keeps a rolling buffer, so older events eventually scroll off. Don’t click Clear Buffer before you’ve downloaded it.

Verifying the update

After reboot, the LED shows the startup sequence:

• A series: 3 quick blinks → idle
• P/X series and H series: 3 quick blinks → 5 slow (Wi-Fi) → 10 fast (MQTT), all three means the board is fully connected to the printer.

If the LED doesn’t follow this pattern, see the LED-signals reference in your printer’s assembly guide:

• Bambu A1 Mini, Operation
• Bambu A1, Operation
• Bambu P/X series, LED signals
• Bambu H2S, H2D, H2C - H-series shares the P/X LED reference.

Troubleshooting

Browser shows “No device found” when I click Install. Try a different USB-C cable, some cables are power-only and don’t carry data. Also make sure the controller board’s USB-C port is the one you plugged into (not the printer’s USB port).

Flash fails halfway through. Unplug, wait 10 seconds, re-plug, and retry. If it still fails, hold the board’s BOOT button while plugging in USB-C to force bootloader mode, then release once connected.

Flashing succeeded but LED doesn’t blink the startup sequence. Power-cycle the board (unplug AMS / 5V power for 10 seconds). If still nothing, re-flash with the USB-C method, the OTA partition may have been corrupted.

Can I downgrade? Yes - every series has its previous release in the Previous versions section above (A: v1.40 / v1.30, P/X: v2.92, H: v3.00).