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USB and WiFi

Klipper talks to the BridgeBox over USB or WiFi. Either way, Klipper makes the link key and stores it on the BridgeBox by itself, so there is never a key to type.

USB

[AFC_BridgeBox chain1]
serial_port: auto

With serial_port: auto, AFC finds the BridgeBox on USB and saves which board it took, so the chain keeps that board across restarts. A second chain on auto takes a BridgeBox no other chain uses. If no BridgeBox is plugged in at startup, the chain keeps looking once Klipper is up and picks up a board plugged in later.

Naming the port yourself

You can name the port instead of using auto. Find it with:

ls /dev/serial/by-id/

and set it as the serial_port:

serial_port: /dev/serial/by-id/usb-Espressif_..._if00

Replacing a board

The chain saves the board it found. To move the chain to a replacement BridgeBox, run AFC_BRIDGEBOX_FORGET_BOARD, then RESTART. The chain then takes the next free BridgeBox it finds on USB.

WiFi

This is the easiest way onto WiFi, and the BridgeBox falls back to USB whenever WiFi is down while the cable is in.

  1. Start with the BridgeBox on USB and add connection: wifi to its section:

    [AFC_BridgeBox chain1]
serial_port: auto
connection: wifi

  2. Run FIRMWARE_RESTART.

  3. On a phone, join the BridgeBox's hotspot, named bb-bridge-XXXX after the board. The setup page opens by itself; if it doesn't, browse to http://10.42.42.1.
  4. Choose your network and enter its password. The page shows Connected with the address the BridgeBox got.

Klipper sees the BridgeBox join, stores the link key on it and moves the link to WiFi by itself. The cable can stay in as a fallback or come out.

Use this when the BridgeBox will never be on a USB cable.

  1. Power the BridgeBox. On a phone, join its bb-bridge-XXXX hotspot; the setup page opens by itself, or browse to http://10.42.42.1.
  2. Choose your network and enter its password. Note the address the page shows.

  3. Put that address in the section in place of serial_port: auto:

    [AFC_BridgeBox chain1]
serial_port: tcp://192.168.1.50:8888

  4. Restart Klipper. It stores the link key on the BridgeBox at the first connect.

Tip

Give the BridgeBox a fixed DHCP lease in your router so its address doesn't change.

If the hotspot page doesn't work for you, put the network in the config and Klipper gives it to the BridgeBox over USB once per start:

[AFC_BridgeBox chain1]
serial_port: auto
connection: wifi
wifi_ssid: YOUR_NETWORK
wifi_password: YOUR_PASSWORD

Warning

The password is stored in plain text, so keep this file private. Double quotes and backslashes can't be used, and the password must be 8 to 63 characters, or empty for an open network.

Moving to another printer or network

A BridgeBox remembers its network and the link key of the printer that set it up. Before moving it:

  1. On the old printer, run AFC_BRIDGEBOX_RESET_WIFI. It wipes the BridgeBox's network and key and brings its hotspot back. You can also hold the BOOT button for 10 seconds, which does the same without Klipper.
  2. Stop the old printer's chain from reaching for it: set connection: usb or remove the section. A chain left on connection: wifi keeps reconnecting to the board's old address and takes it back from the new printer.
  3. Set it up on the new printer as above.

AFC_BRIDGEBOX_RESET_WIFI is refused during a print and while the BridgeBox is not connected.

If Klipper loses the BridgeBox during a print, AFC pauses the print after 5 seconds of silence. A load in progress rides out 12 seconds before it fails. When the link comes back, the units come back online by themselves.

Next step: Configuration