Add Anet ET4/ET4P motherboard & Anet TFT28/TFT35 support

[thisiskeithb]

Description

The Anet ET4 (with A4988s) and ET4P (with TMC2208s in standalone mode) are STM32F407VGT6-based motherboards used in Anet's ET4 and ET5 series of printers (standard, X, and Pro) as well as the Labist ET4. This PR brings in initial support for these boards as well as Anet's TFT28 & TFT35 TFTs from davidtgbe/Marlin / anet-3d/Marlin/tree/Anet-Marlin-bugfix-2.1.0.

Benefits

Existing Anet ET4/5 users who flash their boards with the OpenBLT bootloader will be able to use Marlin on their printers.

Note: Anet plans to ship Marlin on their printers at some point in the future, so users won't have to update their bootloader.

Configurations

Any of the Anet ET4 or ET5 configs will work for testing.

[thinkyhead]

I've brought in a number of changes from the ET4 branch I was working on. I'm not about the Color and FSMC patches, but they're included here for evaluation.

[thisiskeithb]

I've brought in a number of changes from the ET4 branch I was working on.

Ok, great! I didn’t realize you had something going, so apologies if this was too early.

Anet reached out to me and sent along the referenced firmware so I wanted to get a draft going for feedback/testing.

I'm not about the Color and FSMC patches, but they're included here for evaluation.

Good to know. I’ve seen stock ET4/5 machines running with TFT_COLOR_UI, but since I’m waiting on a real printer to arrive, I wasn’t able to test on real hardware yet.

[thinkyhead]

apologies if this was too early…

I have been meaning to get it tested, since I do have an ET4 here. The main question is whether the IS_ANET_ET customizations here (making the user interface blue and orange, etc.) are desirable or necessary. Also, the pins file I have specifies a CUSTOM_CABLE for the SD connection so we might need to look at that. Also, I have some differences in my platformio.ini file with consideration for future ET5 support, but those may not be too important.

It's possible that you have to name the file ET4.bin for it to flash from the SD card, but I haven't tried. Maybe it can be flashed over USB. I'll mess with it soon and figure out what's required. I'll start out by flashing the latest firmware binary from Anet so I can see a working result first.

[thisiskeithb]

The main question is whether the IS_ANET_ET customizations here (making the user interface blue and orange, etc.) are desirable or necessary.

Probably not. That can always be set by the various ET* configs.

Also, the pins file I have specifies a CUSTOM_CABLE for the SD connection so we might need to look at that.

I saw that in the pins file originally, but didn't see a matching #ifdef CUSTOM_CABLE where that'd be useful anywhere, so I removed it. 🤷‍♂️

It's possible that you have to name the file ET4.bin for it to flash from the SD card, but I haven't tried. Maybe it can be flashed over USB.

I pinged Anet again for more info/a status on where they were at with their own bootloader, but haven't heard back.

[Sebazzz]

I don't see the build offset of 0x10000, which is required if you use OpenBlt bootloader (and probably any bootloader). Is that deliberate?

[thisiskeithb]

The bootloader I referenced above doesn't use that offset, so it will likely vary depending on which bootloader you go with.

Anet is working on their own bootloader, so that will also likely change once available.

ST-Link Utility screenshot for the referenced bootloader:

[Sebazzz]

The bootloader I referenced above doesn't use that offset, so it will likely vary depending on which bootloader you go with.

That's not a bootloader right? That's flashing directly via ST-Link. OpenBLT allows flashing through SD card. You only need to flash OpenBLT once.

Anet is working on their own bootloader, so that will also likely change once available.

It will - but we're not there yet 😄

[thisiskeithb]

That's not a bootloader right?

Oops, yes.

I now see the following in David's fork below the ET4 environment:

# Uncomment next line to build for use with BootLoader.
# Offset depends on BL used.
#board_build.offset  = 0x10000

# Uncomment next 2 lines to build for debug.
#build_type = debug
#debug_build_flags = -O0 -ggdb3 -g3

So it still depends on how you plan to update. Is OpenBLT the prefered/most common bootloader for Anet ET4/5 modders?

[thinkyhead]

I have to work with OpenBLT for a project and would enjoy hearing about others' experience configuring this bootloader. I hear it's quite configurable, but the "conf.h" files are pretty sparse.

[Sebazzz]

Let's just say that taking your printer apart and flashing it with an ST-Link every time you've compiled Marlin gets a bit annoying 😉

The default precompiled release of OpenBLT works great:

• It logs the flashing log to the SD card
• It shows progress on the TFT
• It is fast

This is on the Anet ET4 Pro. But since it has the same motherboard I assume this is included in your PR. It just has a little different config.

[thisiskeithb]

Let's just say that taking your printer apart and flashing it with an ST-Link every time you've compiled Marlin gets a bit annoying

I get it. Some of my printers with an easy to access SWD header are still a pain to fix with an ST-Link when I need to recover the board. I was just wondering if OpenBLT is the standard when it comes to installing a bootloader on these boards since I’m not super familiar with the Anet ET modding scene yet.

If it is, then it makes sense to enable the 0x10000 offset and update the ET4 readme to call out flashing OpenBLT and include a similar readme with the other pending configs.

This is on the Anet ET4 Pro. But since it has the same motherboard I assume this is included in your PR.

This PR adds the Anet ET4 board which is used in ET4 and ET5 printers. MarlinFirmware/Configurations#322 has configs for more ET4 printers and I hope to add ET5 configs once mine gets here this week & I can verify everything works.

I requested more info from Anet about the board revisions and if any other models use the ET4 board as well as TFT types so we can improve the existing ET4 configs and pending ET configs as-needed.

[Sebazzz]

I was just wondering if OpenBLT is the standard when it comes to installing a bootloader on these boards since I’m not super familiar with the Anet ET modding scene yet.

I do believe David's Marlin for is the standard when it comes to the Anet ET series, so I think his bootloader is too.

[thisiskeithb]

I just updated the environment to specify using davidtgbe's OpenBLT bootloader and updated board_build.offset to 0x10000.

I'll be sure to update any related ET series' config readmes to make sure it's clear that ET owners will need to use this bootloader when compiling with this environment.

[thisiskeithb]

@thinkyhead: Which board/TFT display does your printer have? Here's the "ET4-MB_V1.1" pinout which uses SPI and not FSMC like what was added in those TFT patches:

(H/T to @rhapsodyv for finding that)

[rhapsodyv]

I will push the code for TFT SPI on a F4 board, and we can revert some of those commits that changed the FSMC and TFT code.

[thisiskeithb]

My ET5 X arrived this week, so I will be unboxing it this weekend & getting things setup for testing 🙂

[rhapsodyv]

I think everything is OK now.

[thisiskeithb]

@xC0000005: If you're on Marlin's discord, can you reach out to me about reverse engineering the stock bootloader/update process on these boards? @rhapsodyv is confident that you can work your magic like you did for the chitu bootloader mess 🙂

[xC0000005]

If anyone else has one of these and wants to try disk based update, the thing that stops Marlin from ever booting is that the stock boot loader wants the _estack value to be less than 64k (I'd set it to 63k just to be safe), so set maximum_ram_size to ~63k and see if it doesn't work better with completely stock boot loader. (edit, I meant 63k)

[thisiskeithb]

I just found out the Labists ET4 is OEM'd by Anet & uses an ET4 motherboard & TFT28, so this PR works for those printers too! Here's a PR for that printer.

[chepo92]

How to wire an STlink V2 to upload the Bootlader? I see the V (or U?) and G marks on a header, but im missing labels of the other 2 pins

[thisiskeithb]

How to wire an STlink V2 to upload the Bootlader?

I put together readmes for each of the ET4/5 configs that walk you through everything. Example: https://github.com/MarlinFirmware/Configurations/tree/import-2.0.x/config/examples/Anet/ET5X

[chepo92]

Can anyone confirm that this is working with ET4 version with (inductive/capacitive) probe (no z endstop)?
With M119 i see no change in probe status (checked that probe works, lights on and the signal cable changes voltage when put close to bed)
Is PC3 pin correct?
#define Z_MIN_PROBE_PIN PC3

Also M43 I shows no probe pin nor PC3 defined
M43.txt

Tested lastest bugfix with ET4 ET4X and ET+ config, same result

Edit: It seems to be a short of the signal trace to ground in the board i'm using

[Sebazzz]

@chepo92 Compare with my old Marlin fork: https://github.com/Sebazzz/ANET-ET4Pro-Marlin/
This one does work on the ET4 Pro.