Firmware¶

This document provides instructions for building and flashing the Katapult bootloader for the iHeater microcontroller. The Katapult bootloader enables flashing Klipper firmware via USB and includes guidance on flashing Klipper firmware onto the iHeater controller.

Requirements¶

STM32F042F6P6
iHeater board
USB cable
Linux system (e.g., Raspberry Pi or 3D printer)

If you cannot build and flash firmware on the printer

Refer to the WSL section

Building Katapult¶

Clone the Katapult repository:

git clone https://github.com/Arksine/katapult.git
cd katapult
make menuconfig

In menuconfig, select:

Build the firmware:

make

The firmware will be created in out/katapult.bin.

Flashing Katapult via DFU¶

This step is only needed once to install Katapult.

Preparation:¶

Install dfu-util if it is not already installed:

sudo apt install dfu-util

According to the board version:

r1r1.1

Set the jumper to BOOT0 and power cycle the board (or press the RESET button). The microcontroller will boot into DFU mode.

Press and hold BOOT, then power cycle the board (or press the RESET button), and release BOOT. The microcontroller will boot into DFU mode.

Check the connection:

lsusb

You should see:

ID 0483:df11 STMicroelectronics STM Device in DFU Mode

Flash Katapult:¶

Put it in DFU mode.

Run the command:

dfu-util -a 0 -D out/katapult.bin -s 0x08000000:leave

Example of successful flashing:

Downloading to address = 0x08000000, size = 4968
Download        [=========================] 100%         4968 bytes
Download done.
File downloaded successfully
Transitioning to dfuMANIFEST state

Exit DFU mode.

After reboot:

ls /dev/serial/by-id/*

You should see:

/dev/serial/by-id/usb-katapult_stm32f042x6_XXXXXXXXXXXXXX-if00

If there are permission issues when flashing, run:

sudo chmod 777 /dev/serial/by-id/usb-katapult_stm32f042x6_XXXXXXXXXXXXXX-if00

if something went wrong

erase the memory of the MCU and repeat the previous steps

touch /tmp/empty.bin

dfu-util -a 0 -d 0483:df11 -s :mass-erase:force -D /tmp/empty.bin

Notes¶

Katapult uses the first 8 KiB of flash, so set 8 KiB bootloader offset in Klipper.
DFU mode can be entered using either a double Reset or a button on GPIO (PA4).
If PA13/PA14 are used for SWD.
Once Katapult is flashed, ST-Link is no longer needed - all further work is done via USB.

Flashing Klipper to iHeater¶

Compile the firmware:¶

cd ~/klipper

make menuconfig

Enable extra low-level configuration options

Micro-controller Architecture (STMicroelectronics STM32)

Processor model (STM32F042)

Bootloader offset (8KiB bootloader)

Clock Reference (Internal clock)

Communication interface (USB (on PA9/PA10))

Disable all unnecessary options:¶

[*] Support micro-controller based ADC (analog to digital)
[ ] Support communicating with external chips via SPI bus
[ ] Support communicating with external chips via I2C bus
[*] Support GPIO based button reading
[ ] Support Trinamic stepper motor driver UART communication
[ ] Support 'neopixel' type LED control
[ ] Support measuring fan tachometer GPIO pins
    *** LCD chips ***
[ ] Support ST7920 LCD display
[ ] Support HD44780 LCD display
    *** External ADC type chips ***
[ ] Support HX711 and HX717 ADC chips

Build the firmware:¶

make clean
make

!!! Result should look like: Creating hex file out/klipper.bin

Flash firmware to the iHeater board¶

Install python3-serial if needed

sudo apt install python3-serial

The following assumes Katapult bootloader is already installed

Connect the iHeater to the host in programming mode (hold the MODE button during connection or double-press RESET).
List serial devices:

ls /dev/serial/by-id/

Example output:

usb-katapult_stm32f042x6_XXXXXXXXXXXXXXXXXXXXXXXX-XXXX

Install flashtool if needed:

pip install flashtool

Replace the ID with your actual ID and run:

python3 ~/katapult/scripts/flashtool.py -d /dev/serial/by-id/usb-katapult_stm32f042x6_XXXXXXXXXXXXXXXXXXXXXXXX-XXXX -f ~/klipper/out/klipper.bin

Expected output:

Flashing '/home/pi/klipper/out/klipper.bin'...

[##################################################]

Write complete: 20 pages

Verifying (block count = 319)...

[##################################################]

Verification Complete: SHA = 8A3DDF39A0E70B684DC6BAF74EF8F089EBDD6C18

Flash Success

Verify:

ls /dev/serial/by-id/