BIGTREETECH EBB42 CAN V1.2 with MAX31865 | Klipper Toolboard

The BIGTREETECH EBB42 CAN V1.2 is a toolboard designed for installation around 42 mm extruder stepper motors. It centralises the motor, heater, fan and sensor connections on the toolhead and communicates with Klipper through CAN BUS or USB.

This version includes a MAX31865 interface and supports 2-wire or 4-wire PT100 and PT1000 RTD sensors. A separate TH0 input is also available for 100K NTC thermistors or directly connected PT1000 sensors.

Features

• 40 × 40 mm square format.
• Four M3 mounting holes with nominal 31 × 31 mm spacing.
• Integrated TMC2209 driver operating in UART mode.
• Integrated ADXL345 accelerometer.
• Hotend heater output rated up to 5 A.
• Two fan outputs.
• Endstop, probe, I²C, RGB, USB and CAN connections.
• Selectable 120 Ω CAN termination resistor.

Temperature measurement

• 2-wire PT100 or PT1000 through MAX31865.
• 4-wire PT100 or PT1000 through MAX31865.
• Direct 100K NTC connection on TH0 with a 4.7 kΩ pull-up.
• Direct PT1000 connection on TH0 using the jumper-selectable 2.2 kΩ pull-up.

The DIP switches must match the RTD type and number of conductors. Klipper must also be configured with the correct MAX31865 parameters, wire count, nominal resistance and reference resistance.

Compatibility

The board is intended for Klipper-based printers and toolheads with a suitable mount for a 42 mm board. It may be used in Voron, Rat Rig, VzBot and other custom builds, but compatibility depends on the mechanical mount, wiring, power supply and firmware configuration.

The 120 Ω termination resistor should only be fitted when the EBB42 is located at a physical end of the CAN network. Check the microcontroller and revision printed on the board before compiling the firmware.

Selecting the correct version

For installation around a 36 mm motor, see the EBB36 CAN with MAX31865. If only NTC or direct PT1000 sensors will be used, see the EBB42 CAN without MAX31865.