Introduction

H36 Combo V2.0 is a newly designed high temperature tool board running Klipper firmware. Based on STM32G431CBT3, the maximum operating temperature can reach 125 degrees Celsius (CAN only). It also provides two communication methods: CANBUS and USB. The onboard USBHUB has up to two USB interfaces (or one CAN and one USB), which can be used to connect to the IDM Scanner Leveling Sensor camera, etc.

Version Notes

V2.0 (Currently Available)

1. Change MCU to STM32G431CBT3
2. Reassign pins
3. Lead out the header pins for the SWD interface
4. When the USB-C port is plugged in, it automatically switches to USB communication.

Features

• STM32G431CBT3 MCU, up to 125 degrees Celsius, supports Klipper Firmware
• 6-layer PCB design, all solid capacitors and tantalum capacitors, better heat dissipation
• Onboard RESET and BOOT0 buttons for easy firmware update
• Fan control/heating both use independent high-power MOS, safer and lower heat generation
• Onboard 5V@3A DC-DC, 5V peak load can reach 15W
• XT30 interface, custom cable comes with the board
• Onboard USB2.0 HUB, 3x USB2.0 interface (one of which is connected to MCU)
• Support CAN/USB2.0 connection
• Onboard TMC2209
• 3x 3pin Fans, 3x IO with level converter, 1x RGB,1x Heat, 1x thermistor,1x status LED
• ADXL345 Accelerometer onboard
• USB-C onboard for Firmware update

Applications

Print Head with NEMA14/36mm Motor

Hardware Specification

Operating limits

Physical Connections

Pin Out

Thanks to Esoterical for creating this image.

IO.0: PB3
IO.1: PB4
IO.2: PB5
IO.3/RGB0: PA10
IO.4/RGB1: PA9
# IO.0 - IO.4 with level conversion (pull-up), it can be used as 5V/24V level input and output!

FAN0: PB12
FAN0_TACH: PB14 
FAN1: PB2
FAN1_TACH: PB1 
FAN2: PB0
FAN3: PB15
FAN3_TACH: PA8 

Heat: PB13
Thermistor (2.2k pull up): PA3

Driver_EN: PC14
Driver_DIR: PC15
Driver_STEP: PB9
Driver_UART: PB6
Driver_DIAG: PA13

ADXL345
spi_bus: spi1
adxl345_cs_pin: PA4
adxl345_spi_software_sclk_pin: PA5
adxl345_spi_software_miso_pin: PA6
adxl345_spi_software_mosi_pin: PA7

CAN_RX: PA11
CAN_TX: PA12

Thermistor next to TMC2209 (4.7k pull up) : PA0

CAN USB switch: PA2
# logic Low = COM to A PORT  CANBUS
# Logic High = COM to B PORT  USB

Extra Pins Function

For more info, Please refer to STM32G431CBT3 datasheet

How to Use Hardware I2C

• Based on the G431 header files within Klipper, you should select PA13/PA14 or PA14/PA15 as the hardware I2C interface to connect your external devices—such as the I2C Eddy.
• According to feedback from some customers, it appears that PA14/PA15 is easier to use.
• You can also get more information from the Klipper documentation：

https://www.klipper3d.org/Config\_Reference.html?h=i2c#common-i2c-settings

Description Of Connections

IO.0 and IO.1 are located in the same connector and can be used as XY endstops, and IO.2 can be used as a probe. In addition, IO.0 - IO.5 have level conversion (with pull-up resistors) , IO.01, IO.2 have voltage selectors (5V or 24V) pin header, IO.3 IO.4 have voltage selectors (5V or 24V) pads. All the IOs can be used as inputs or outputs, such as RGB ,Servo, Endstops, and can be configured according to your other needs.

Connecting Fans

3 Wire Fans

3 wire fans can be connected by following the Pin Out above.

4 Wire Fans

4 wire fans require the use of 2 connectors to enable the control on the PWM wire and to monitor the TACH wire.

H36 Combo V2 Connections

Fan0:
24V > V
GND > PB12
TACH > PB14

IO.3:
PWM > PA10

Creality 4020 Blower Fan Pin Out

Red > 24V
Black > GND
Green > PWM
Yellow > TACH

Configuration

[output_pin fan0_power] #keeps 24V on for part cooling fan as GND(PB12) is a mosfet
pin: H36_combo:PB12
value: 1
shutdown_value: 0

[fan] # Part cooling fan PWM
pin: H36_combo:PA10
max_power: 1.0
shutdown_speed: 0.0
cycle_time: 0.00004   # 25kHz for 4-wire PWM fan
hardware_pwm: false
kick_start_time: 0.5
tachometer_pin: ^H36_combo:PB14

USB / CAN Selection

XT30 and USB2/CAN both use CAN to communicate refer to the instructions below for connecting the H36 via CAN.

XT30 and USB2/CAN both use USB to communicate refer to the instructions below for connecting the H36 via USB.

Header Jumpers

IO.0+1 , IO.2 , Fan0 , Fan1 can select the power supply voltage through the jumper cap.
As shown in the figure, the two pins on the left are connected together for 24V, and the two pins on the right are connected together for 5V.

LED Indicators

Communication

Connection To Pi

H36 combo V2 can be connected to Pi via USB or CANBUS. Select by PA2, refer to USB / CAN selection.

Via CAN

Since the Raspberry Pi does not have a CANBUS interface, it is usually connected only after the CANBUS interface is expanded through an expansion chip. Commonly used ones include the MCP2518 SPI to CAN module (CanHat), USB to CAN module (eg: UCAN), Klipper USB to CAN Bridge Mode, and a Linux host computer with a native CAN interface (eg: CM68).

Via USB

When using USB connection, you can use the adapter board we provide to directly connect to the USB interface of PI.

Firmware Guide

Firmware Configuration And Compilation

With Katapult Bootloader

If you need to use a bootloader, we recommend using katapult. The following is not configured for reference:
For katapult use, refer to: https://github.com/Arksine/katapult

shell
cd ~/katapult
make menuconfig
make flash FLASH_DEVICE=0483:df11

USB

CAN

cd ~/klipper
make menuconfig
make
cd ~/katapult/scripts
#when using CAN communication
python3 flashtool.py -i can0 -f ~/klipper/out/klipper.bin -u <uuid>
#when using USB communication
python3 flashtool.py -d <serial device> -b <baud_rate> -f ~/klipper/out/klipper.bin

USB

CAN

Klipper With No Bootloader

H36 uses the bootloader-free mode by default, and the configuration is as follows:
USB

CAN

Firmware Upload

Before executing the following commands, you need to enter DFU mode before you can compile and burn the firmware. As shown in the figure above,

• press and hold BOOT0,
• then press the RESET button for one second,
• then release RESET,
• wait for 3 seconds,
• and release BOOT0.

Use " lsusb" to check if a DFU device appears. If yes, upload firmware. If no, repeat the above steps.

make flash FLASH_DEVICE=0483:df11

under katapult Klipper uploading, Please refer to:

https://github.com/Arksine/katapult?tab=readme-ov-file#uploading-klipper

Attachments And Other Documents

2D，3D , SCH and config template file, please go to our github:

https://github.com/FYSETC/H36\_Combo\_V2

Where To Buy

www.fysetc.com

Technical Support Channel

support@fysetc.com

https://discord.gg/4A5QDCYx

Updated on: 03/08/2026