FarmLoop firmware

Firmware runs on the ESP32 controller board inside your FarmLoop module. It handles the bending routine, limit-switch gestures, door control (P/X 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 you have, check the printer model, each Bambu family runs a different ESP32 variant, so they use different firmware files.

Current firmware

Bambu A Series

Bambu A1 Mini, A1

v1.40 April 2026

Update recommended, boards shipped with v1.30.

Release notes

• New startup procedure that tests actuators and fan
• Improved trigger reliability and stability
• OTA firmware updates now enabled

⚡ USB-C flash v1.40 USB-C flash (Chrome / Edge only) USB-C flash needs HTTPS Download OTA .bin

ESP32-C3 · full firmware (offset 0)

Bambu P/X Series

Bambu P1P, P1S, P2S, X1C

v2.92 April 2026

Update recommended, boards shipped with v2.9.

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)

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

ESP32-S3 · full firmware (offset 0)

Bambu H Series

Firmware is in development. Sign up at 3d-farmers.com/pages/newsletter-signup for release notifications.

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 on the running board:
   • A series: five quick taps on the LIMIT SWITCH within 3 seconds
   • P/X series: five quick taps on the DOOR BUTTON within 3 seconds
3. Connect your phone or laptop to the Wi-Fi network FarmLoop (password 3D-Farmers).
4. Open http://farmloop.local or http://192.168.4.1.
5. Scroll to the Firmware Update card, pick the _OTA.bin file, and click Upload.
6. 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.

Verifying the update

After reboot, the LED shows the startup sequence:

• A series: 3 quick blinks (boot) → idle
• P/X 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

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? Not currently. Older .bin files aren’t published. If you need to roll back, contact contact@3d-farmers.com.