Bondtech INDX

This document describes how to set up and calibrate a Bondtech INDX toolboard with Kalico. The INDX toolboard drives an inductive nozzle heater with a contactless IR temperature sensor, and runs its own PID controller on the toolboard MCU.

Support consists of the [indx] host module (see config reference) and dedicated firmware for the toolboard's SAME51 MCU, both included in Kalico. Kalico is the reference implementation; the BondtechAB/indx_klipper module tracks Kalico to provide compatibility with mainline Klipper. Also see the original commissioning guide.

Flashing the firmware

Connect the toolboard over USB and bridge the CAN RESET jumper while powering up to force the bootloader. The device should show up as "INDX Toolboard Bootloader" with USB id 04d8:e483:

$ lsusb | grep INDX

Kalico ships a ready-made build configuration. From the Kalico directory run:

$ KCONFIG_CONFIG=board_configs/bondtech_indx_usb.config make
$ KCONFIG_CONFIG=board_configs/bondtech_indx_usb.config make flash FLASH_DEVICE=04d8:e483

Configuration

A minimal configuration looks like:

[mcu indxmcu]
serial: /dev/serial/by-id/usb-Bondtech_INDX_<YOUR SERIAL>-if00

[indx]
mcu: indxmcu

[extruder]
sensor_type: indx
min_temp: 0
max_temp: 300
heater_pin: indx:heater
control: watermark
nozzle_diameter: 0.4
filament_diameter: 1.75
step_pin: indxmcu:motor_step
dir_pin: indxmcu:motor_dir
enable_pin: !indxmcu:motor_enable
microsteps: 32
rotation_distance: 5.7

[tmc2240 extruder]
cs_pin: indxmcu:motor_cs
spi_software_sclk_pin: indxmcu:motor_sclk
spi_software_mosi_pin: indxmcu:motor_mosi
spi_software_miso_pin: indxmcu:motor_miso
rref: 24000
run_current: 0.6

[fan]
pin: indxmcu:part_cooling
tachometer_pin: indxmcu:part_cooling_tacho

The [indx] module registers named aliases for all toolboard pins (such as indxmcu:motor_step, indxmcu:part_cooling, indxmcu:endstop) and configures the SERCOM peripherals automatically. The extruder heater is exposed as the virtual pin indx:heater and the nozzle temperature as sensor_type: indx. The heatsink fan is managed by the toolboard module itself: it turns on whenever the heater is active, the nozzle is hot or a stepper on the toolboard is enabled, and a blocked fan triggers a shutdown.

Calibration

The heater will not heat until it has been calibrated. With the nozzle cold and the printer idle run:

INDX_CALIBRATE

This first tunes the inductive coil drive timings and then performs a heat/hold/cooldown cycle to fit the thermal model. Afterwards run SAVE_CONFIG to persist the results.

Optionally calibrate the part cooling fan compensation (requires the part cooling fan to be configured):

INDX_FAN_CALIBRATE
SAVE_CONFIG

The thermal model also accounts for the energy carried away by molten filament. Either set the filament parameters directly:

INDX_SET_MODEL_PARAMS FILAMENT_DENSITY=<g/cm3> FILAMENT_HEAT_CAPACITY=<J/g/K>

or measure them while loading filament with the nozzle at printing temperature:

INDX_LOAD_FILAMENT

Use INDX_CLEAR_FILAMENT to reset the filament parameters, and SAVE_CONFIG to persist any of these values.

See the G-Code reference for the full list of INDX commands and their parameters.