Marlin for ET4/5 series 3D printers

This project is an effort to try to adapt the Anet ET4/ET5 motherboard and display for use with Marlin. Anyone can contribute to completing this project. Feedback is also welcome.

Context

As I don't have a blog, I would like to leave a personal opinion here related with this project experience. To whom it may concern.

I started this project as a hobby, on the one hand in response to the demand from the Anet ET series user community (including myself) for a quality and versatile firmware for their printers, and on the other hand, of Anet's refusal to provide solutions to problems and shortcomings of the stock firmware (a change.org was even launched)

Without much knowledge of either Marlin or the closed ET hardware, and with help from the community, we have Marlin in the ET series from some time now. It is hard to believe that a company that claims to be a leader in the 3D printing industry will not be able to employ some engineering resources to port Marlin. Or even to improve its own firmware, which most remarkable milestone on recent released V3.0.0 (jump from V1.x), is to support some new languages...

It was also a surprise (or not so much seeing it in perspective) that, in a very timely manner, Anet contacted me to get on the open source bandwagon and offer me a paid collaboration, which, although it never took place, they rushed to make it public along with an open source campaign, providing Anet a kind of reconciliation with the community appearing to be involved in this project, and a way of selling more printers. Objective accomplished.

In summary, after some time dealing with Anet, my personal experience has been regrettable. The lack of seriousness shown by the company (even the CEO) is hard to believe. The only concern in this whole project has been from the marketing and sales point of view, never from their users needing, as they want to do see. Anet's style is more in line with the "let them solve it themselves, and we will take advantage of it" of a mediocre company of the heap than with the innovative company, concerned about the user experience that they want to pretend to be (or show).

Current status

Working:

• XYZ Steppers
• Extruder
• SD Card
• USB comunication / pronterface
• TFT
• Filament runout detector
• EEPROM (Flash emulation)
• Powerloss (Thanks to Zhiniukas & SidDrP)
• Bltouch
• PC/SD firmware load/update
  • I've managed to get working OpenBLT, (PC-USB / SD / DFU) updates. I'm still looking for a way to do a first time flash without flasher. A hardware flasher is very recommended for its price.
• Onboard EEPROM I2C (4Kb/512B)
  • Adapted and working, but not usable. Onboard EEPROM IC is too small to store marlin config, so, expect EEPROM errors if used. Use FLASH_EEPROM_EMULATION instead or solder another 24CXX EEPROM IC (24C32 or above recommended).
• Onboard FLASH (128Mb/16MB)
  • Ready. Tested LVGL from MKS (ET5 TFT). Not used, as not dedicated or universal LVGL UI has been designed AFAIK.

    On progress:

• No work in progress

  Known bugs:

I have enabled issues tab. Please, try to be detailed regarding use cases and other useful information like hardware and software context. To get help on creating an issue see this.

Build/Installation

DISCLAIMER: Not for production use. This is an unfinished project and under development. I am not responsible for what may happen to the motherboard or printer. Use only at your own risk.

Currently you can only flash this firmware using a flasher (stlink, jlink, bmp etc), unless you already have flashed the openblt bootloader (BL).

Before flashing this firmware (optional, but recommended):

First time, I recommend making a backup of your firmware. At least your bootloader (addresses from 0x08000000 to 0x08010000). This way, you can always recover/return to stock firmware by:

1. flashing the bootloader backup, from address 0x08000000 to 0x8010000.
2. flashing any of the available Anet firmwares from address 0x08010000 onwards.

If you don't perform this step, and, just in case of brick, there are copies of stock firmware ET4 releases and bootloader below on resources section.

Considerations

Despite of using "ET4" naming, this firmware is valid for both ET4 and ET5 printers. Both printers mount the same board up until now.

You have two options to install/update this firmware:

• Option A > Not using a bootloader (BL)
  • Firmware (Marlin) starts directly when you switch on the printer.
  • You need the flasher to perform firmware installation/updates.
  • Environment needs to be set to Anet_ET4_no_bootloader.
• Option B > Using a bootloader along with this firmware
  • When you switch on the printer, bootloader (BL) starts first, and, if there are not any firmware updates incomming (on SD or through PC-USB), it loads the firmware (Marlin).
  • You need the flasher to flash the BL the first time. Once it is flashed, you MUST install/update your FW through your BL, either by SD card or USB-PC. You MUST NOT use the flasher to install/update the FW, as it will not work.
  • Environment needs to be set to Anet_ET4_OpenBLT.

Step One: Building from sources

1. Download or clone this repo. Ensure you build the firmware with latest sources, as firmware.srec file will not be built with older sources.

2. You have two options to configure your own Marlin build:

   • a) Recommended. Use EasyConfig for a simple configuration experience.
   • Make sure you read the whole EasyConfig.h file carefully. It contains instructions to configure it.
   • EasyConfig will override some paremeters of configuration.h and configuration_adv.h.
   • b) Configure your build from scratch.
   • User configurations are neither updated nor maintaned. Please, read the readme.md inside the config folder. Don't copy paste these files.
   • Marlin configurations can also be a place to take a look. Don't copy paste these files as there could be a version mismatch between them and this repo.
   • Make sure to modify your config.h and config_adv.h according to your ET4/5 model (ET4, ET5, ET4 PRO, ET4+, ...)
   • Settings as driver model (A4988/TMC2208), Z endstop position (UP/DOWN), TFT resolution, XYZ size, homming offsets, auto bed levelling sensor, etc, need to be defined according to your model.
   • Fine tunning could be needed (e.g. XYZE steps or offsets, Jerks, JD, LA, etc).

3. Build project with platform.io on VS code is recommended. Default environment to build is set to Anet_ET4_OpenBLT. There are many tutorials on the web. You can follow them, ADAPTING steps to build this project. This one here in spanish made by me, and just another one here.

4. If everything went well, you will find marlin binary files with extension .[elf|bin|srec], generated in the build output folder:

   <src_code_base_folder>\.pio\build\ET4\

Step two Flashing/Installing the firmware

There are several tutorials available for stlink/j-link flashers. Take a look to them.

You have two options to install/update this firmware:

• Option A > If you are going to use the firmware without bootloader (environment Anet_ET4_no_bootloader):
  • It is assumed you have built your firmware with no offset.
  • As the firmware has been built without offset, and lacks of a bootloader, you have to just flash your firmware binary file (step 1.5) with your preferred flasher from address 0x8000000.
• Option B > If you are going to use the firmware with bootloader (environment Anet_ET4_OpenBLT):
  • You need to flash the bootloader from address 0x08000000. This step needs to be performed just once, so, you can skip this step if you have already done so. You can download the precompiled bootloader binary, or, you can build it yourself from source code using STM32 Cube IDE.
  • After flashing the BL, you can disconnect your flasher, it will not be used anymore.
  • Now it is time to install de firmware. BL will assist us in this task, so, you must use a SD-CARD OR USB-PC/microboot to flash perform this step.
  • SD-CARD -> Copy file firmware.srec from build folder (step 1.5) in the root folder of the SD-CARD.
  • USB-PC/microboot ->
    • Download microboot software. It is uploaded to github and you can download it from here.
    • Extract the .zip file you have just downloaded and browse to the folder openblt/Host/. You will find the microboot.exe executable.
    • Connect your printer via USB to your PC and get the COM port number.
    • Open microboot.exe executable and configure COM port number and speed (115200) through settings button. Then, click browse and search for the file firmware.srec. You will find it in the output build folder (step 1.5).
  • Switch off and then switch on the printer to begin the installation/update process.
  • Screen will be white during the process, and, after 3 or 4 minutes, Marlin will appear on the screen. If you have latest OpenBLT release, you will see the update process on screen and Marlin will start after flashing process.

You can connect with pronterface to corresponding COM port @250000bps.

Flashing considerations

If you use bootloader, you must not use the flasher to install/update the FW. The bootloader inserts a special checksum in the firmware during the install/update process. Bootloader checks for this checksum before jumping to the firmware. If you use your flasher to install the firmware, this checksum is not written, and, therefore, bootloader will not boot the firmware , and your screen will be white. and OpenBLT will ask you to flash a firmware.

DFU mode (Device Firmware Upgrade) has been added to the bootloader. You can enter to it just by pressing touchscreen while switching printer on. By using DFU mode you can even update your bootloader without needing a hardware flasher, just using the PC-USB and the right tool.

More info:
SD-CARD update process
PC-USB update process OpenBLT project

Hardware

MCU: STM32F407VGT6 ARM CORTEX M4
DRIVERS: TMC2208 (silent) / A4988 (noisy)
USB TO SERIAL CONVERTER: CH340G
SERIAL FLASH MEMORY: WINBOND W25Q128JVSQ (128M-bit)
EEPROM: AT24C04C (ATMLH744 04CM) 4 Kb
LCD ET4: ST7789 @ 320x240 | STP320240_0280E2T (40P/1,5): ST7789 (YT280S008) | ST7789V
LCD ET5: ST7796S @ 480x320
TOUCH: XPT2046
MOSFETS (BED/HOTEND): G90N04
CLK: JF8.000 (8MHZ MCU EXT CLK)
CLK: JF12.000 (12 MHZ USB-UART CLK)
SCHOTTKY DIODE: SS56
REGULATOR: AMS1117 3.3 DN811
MOSFET: 030N06
MOSFET: A19T
STEP DOWN DC CONVERTER: XL2596S -5.0E1 83296
VOLTAGE COMPARATOR: 293 STG9834 / LM293DT

Pin mapping

E-STEP => PB9
E-DIR => PB8
E-ENABLE => PE0

X-STEP => PB6
X-DIR => PB5
X-ENABLE => PB7

Y-STEP => PB3
Y-DIR => PD6
Y-ENABLE => PB4

Z-STEP => PA12
Z-DIR => PA11
Z-ENABLE => PA15

Y-LIMIT => PE12
X-LIMIT => PC13
Z-LIMIT => PE11

TEMP_BED => PA4
TEMP_EXB1 => PA1

END_FAN => PE1
LAY_FAN => PE3

END_CONTROL => PA0
BED_CONTROL => PE2

LV_DET => PC3
MAT_DET1 => PA2
POWER_LOSS_DET => PA8 (PANET)
POWER_LOSS_SUPERCAP_SWITCH => PA3 (Zhiniukas & SidDrP)

SDIO_D2 => PC10
SDIO_D3 => PC11
SDIO_CMD => PD2
SDIO_CLK => PC12
SDIO_D0 => PC8
SDIO_D1 => PC9
TF_DET => PD3

USB_USART1_TX => PA9
USB_USART1_RX => PA10

RESET_BTN => NRST (14)
LED_D2 => PD12

WINBOND_CS => PB12
WINBOND_DO => PB14
WINBOND_DI => PB15
WINBOND_CLK => PB13

EEPROM_A1 => GND
EEPROM_A2 => GND
EEPROM_SDA => PB11
EEPROM_SCL => PB10

P1_1_LCD_9_CSX => PD7
P1_2_LCD_11_WRX => PD5
P1_3_TOUCH15/CS => PB2
P1_4_TOUCH_14_DIN => PE5
P1_5_TOUCH_12_DOUT => PE4
P1_6_TOUCH_16_DCLK => PB0
P1_7_TOUCH11/PENIRQ => PB1
P1_8_LCD_12_RDX => PD4
P1_9 => GND
P1_10 => 3.3V

P2_1_LCD_15_RESX => PE6
P2_2_LCD_10_DCX => PD13
P2_3_LCD_26_DB9 => PD15
P2_4_LCD_25_DB8 => PD14
P2_5_LCD_28_DB11 => PD1
P2_6_LCD_27_DB10 => PD0
P2_7_LCD_30_DB13 => PE8
P2_8_LCD_29_DB12 => PE7
P2_9_LCD_32_DB15 => PE10
P2_10_LCD_31_DB14 => PE9

Resources

• ET4 Telegram Spanish Group Resources
• ET4 Board and specs
• Bltouch installation
• Change boot image
• Build Marlin (ES)
• EasyConfig.h
• OpenBLT project

Acknowledgements

• To the mates of the Telegram Anet ET4 spanish group, specially to @Solidnon, who lent his board for testing when the project was not even started.
• To @uwe and @mubes from Black Magic Probe team, and to Ebiroll (BMP/ESP32).
• To all contributors and testers of this branch and, specially, of Marlin master branch.

Marlin 3D Printer Firmware

Marlin 3D Printer Firmware

Additional documentation can be found at the Marlin Home Page. Please test this firmware and let us know if it misbehaves in any way. Volunteers are standing by!

Marlin 2.1 Bugfix Branch

Not for production use. Use with caution!

Marlin 2.1 takes this popular RepRap firmware to the next level by adding support for much faster 32-bit and ARM-based boards while improving support for 8-bit AVR boards. Read about Marlin's decision to use a "Hardware Abstraction Layer" below.

This branch is for patches to the latest 2.1.x release version. Periodically this branch will form the basis for the next minor 2.1.x release.

Download earlier versions of Marlin on the Releases page.

Example Configurations

Before you can build Marlin for your machine you'll need a configuration for your specific hardware. Upon request, your vendor will be happy to provide you with the complete source code and configurations for your machine, but you'll need to get updated configuration files if you want to install a newer version of Marlin. Fortunately, Marlin users have contributed dozens of tested configurations to get you started. Visit the MarlinFirmware/Configurations repository to find the right configuration for your hardware.

Building Marlin 2.1

To build and upload Marlin you will use one of these tools:

• The free Visual Studio Code using the Auto Build Marlin extension.
• The free Arduino IDE : See Building Marlin with Arduino
• You can also use VSCode with devcontainer : See Installing Marlin (VSCode devcontainer).

Marlin is optimized to build with the PlatformIO IDE extension for Visual Studio Code. You can still build Marlin with Arduino IDE, and we hope to improve the Arduino build experience, but at this time PlatformIO is the better choice.

Hardware Abstraction Layer (HAL)

Marlin includes an abstraction layer to provide a common API for all the platforms it targets. This allows Marlin code to address the details of motion and user interface tasks at the lowest and highest levels with no system overhead, tying all events directly to the hardware clock.

Every new HAL opens up a world of hardware. At this time we need HALs for RP2040 and the Duet3D family of boards. A HAL that wraps an RTOS is an interesting concept that could be explored. Did you know that Marlin includes a Simulator that can run on Windows, macOS, and Linux? Join the Discord to help move these sub-projects forward!

8-Bit AVR Boards

A core tenet of this project is to keep supporting 8-bit AVR boards while also maintaining a single codebase that applies equally to all machines. We want casual hobbyists to benefit from the community's innovations as much as possible just as much as those with fancier machines. Plus, those old AVR-based machines are often the best for your testing and feedback!

Supported Platforms

Submitting Patches

Proposed patches should be submitted as a Pull Request against the (bugfix-2.1.x) branch.

• This branch is for fixing bugs and integrating any new features for the duration of the Marlin 2.1.x life-cycle.
• Follow the Coding Standards to gain points with the maintainers.
• Please submit Feature Requests and Bug Reports to the Issue Queue. Support resources are also listed there.
• Whenever you add new features, be sure to add tests to buildroot/tests and then run your tests locally, if possible.
  • It's optional: Running all the tests on Windows might take a long time, and they will run anyway on GitHub.
  • If you're running the tests on Linux (or on WSL with the code on a Linux volume) the speed is much faster.
  • You can use make tests-all-local or make tests-single-local TEST_TARGET=....
  • If you prefer Docker you can use make tests-all-local-docker or make tests-all-local-docker TEST_TARGET=....

Marlin Support

The Issue Queue is reserved for Bug Reports and Feature Requests. To get help with configuration and troubleshooting, please use the following resources:

• Marlin Documentation - Official Marlin documentation
• Marlin Discord - Discuss issues with Marlin users and developers
• Facebook Group "Marlin Firmware"
• RepRap.org Marlin Forum
• Facebook Group "Marlin Firmware for 3D Printers"
• Marlin Configuration on YouTube

Contributors

Marlin is constantly improving thanks to a huge number of contributors from all over the world bringing their specialties and talents. Huge thanks are due to all the contributors who regularly patch up bugs, help direct traffic, and basically keep Marlin from falling apart. Marlin's continued existence would not be possible without them.

Administration

Regular users can open and close their own issues, but only the administrators can do project-related things like add labels, merge changes, set milestones, and kick trolls. The current Marlin admin team consists of:

License

Marlin is published under the GPL license because we believe in open development. The GPL comes with both rights and obligations. Whether you use Marlin firmware as the driver for your open or closed-source product, you must keep Marlin open, and you must provide your compatible Marlin source code to end users upon request. The most straightforward way to comply with the Marlin license is to make a fork of Marlin on Github, perform your modifications, and direct users to your modified fork.

While we can't prevent the use of this code in products (3D printers, CNC, etc.) that are closed source or crippled by a patent, we would prefer that you choose another firmware or, better yet, make your own.