[FR] Support TFT SPI screens on STM32H7 platform

[vovodroid]

Is your feature request related to a problem? Please describe.

Currently "SPI TFT is currently only supported on STM32F1 and STM32F4 hardware", while new BTT SKR 3 board is STM32H7 based. Thus it's impossible to replace stock BTT SKR 2 board with SKR 3, as Biqu S1 SE uses TFT35 SPI screen.

I tried to add #include "stm32h7xx_hal.h", but build failed with error

Marlin\src\HAL\STM32\tft\xpt2046.cpp:146:18: error: 'struct SPI_TypeDef' has no member named 'DR'; did you mean 'SR'?
  146 |   SPIx.Instance->DR = data;

https://github.com/MarlinFirmware/Marlin/blob/bugfix-2.1.x/Marlin/src/HAL/STM32/tft/xpt2046.cpp#L146

Are you looking for hardware support?

Biqu S1 SE (Plus)

Describe the feature you want

Support TFT SPI screens on STM32H7 pratform

Additional context

No response

[jmz52]

@vovodroid, will you be able to test various development versions of code?
I can work on this, but I do not have STM32H7 board, so I need someone to test my code.

[vovodroid]

will you be able to test

No, I don't have STM32H7 boards, but it would good to have compiled code ready.

[ellensp]

@jmz52 I have a BTT SKR 3 and a Makerbase MKS TS35 3.5 V2 (SPI interface) and would be able to do some testing.

[vovodroid]

@ellensp Which screen do you use now with SKR 3?

[ellensp]

@vovodroid none, I only got it a few days ago, not in use yet. Thus can be used for testing for a while.

[thisiskeithb]

I have a BTT SKR 3 and a Makerbase MKS TS35 3.5 V2 (SPI interface)

Ditto.

I also have a Biqu SE Plus with the BTT TFT35 SPI TFT (BTT_TFT35_SPI_V1_0) that I can swap an SKR 3/EZ into for testing.

On a related note, the BTT SPI screen is not for sale as a standalone product currently, so it’d be a really limited upgrade path/combo when used on the SE Plus with an SKR 3.

Since MKS sells their SPI TFT as a standalone product at retail, this FR would still make sense to get working On H7 mcus.

[quiret]

#24911

I want to work on this, too. Not sure how generic my implementation is but I am willing to read the docs and get a really good one done. Do you guys want to work on this together instead of everyone getting their own hands into it?

[jmz52]

Halfway there.
It took quite some time (and a new dev board) to make some sense of H7 architecture, but here it is.
Please mind that this is a teaser - code is not fully completed and I still need to merge new H7 code with the original F1/F4 code.

[jmz52]

Code is ready for testing - https://github.com/jmz52/Marlin/tree/H7-wip
Configuration files are from "BIQU/B1 SE", with mainboard changed to BTT_SKR_V3_0 and disabled USB flash drive support.

TFT SPI code works fine, but touch screen support was not tested beyond mere compilation.
I need to do some soldering to connect MKS TS35 to my dev board and I don't have a slightest idea where did I put those 2.54mm pins headers.

[thisiskeithb]

Code is ready for testing - https://github.com/jmz52/Marlin/tree/H7-wip
Configuration files are from "BIQU/B1 SE", with mainboard changed to BTT_SKR_V3_0 and disabled USB flash drive support.

I changed the motherboard to BOARD_BTT_SKR_V3_0_EZ since that's what I have hooked up right now, but I only get a solid white screen with a BTT TFT35 SPI V1.0 (BTT_TFT35_SPI_V1_0 that's defined in the config).

I hooked up an MKS TS35 V2.0 (MKS_TS35_V2_0) and I also get a solid white screen.

[jmz52]

I hooked up an MKS TS35 V2.0 (MKS_TS35_V2_0) and I also get a solid white screen.

Just in case - have you updated TFT and touch pins definitions for MKS TS35?
Also MKS TS35 needed reversed cables, as BTT and MKS uses EXP1/EXP2 connectors with opposite key location.

[thisiskeithb]

Just in case - have you updated TFT and touch pins definitions for MKS TS35?

I commented out HAS_SPI_TFT & used this pinout from the Nano V3 pins file:

#if ENABLED(MKS_TS35_V2_0)

  #define TFT_CS_PIN                 EXP1_07_PIN
  #define TFT_SCK_PIN                EXP2_02_PIN
  #define TFT_MISO_PIN               EXP2_01_PIN
  #define TFT_MOSI_PIN               EXP2_06_PIN
  #define TFT_DC_PIN                 EXP1_08_PIN
  #define TFT_A0_PIN                  TFT_DC_PIN

  #define TFT_RESET_PIN              EXP1_04_PIN

  #define LCD_BACKLIGHT_PIN          EXP1_03_PIN
  #define TFT_BACKLIGHT_PIN    LCD_BACKLIGHT_PIN

  #define TOUCH_BUTTONS_HW_SPI
  #define TOUCH_BUTTONS_HW_SPI_DEVICE          1

  #ifndef TFT_WIDTH
    #define TFT_WIDTH                        480
  #endif
  #ifndef TFT_HEIGHT
    #define TFT_HEIGHT                       320
  #endif

  #define TOUCH_CS_PIN               EXP1_05_PIN  // SPI1_NSS
  #define TOUCH_SCK_PIN              EXP2_02_PIN  // SPI1_SCK
  #define TOUCH_MISO_PIN             EXP2_01_PIN  // SPI1_MISO
  #define TOUCH_MOSI_PIN             EXP2_06_PIN  // SPI1_MOSI

  #define LCD_READ_ID                       0xD3
  #define LCD_USE_DMA_SPI

  #define TFT_BUFFER_SIZE                  14400

  #ifndef TOUCH_CALIBRATION_X
    #define TOUCH_CALIBRATION_X           -17253
  #endif
  #ifndef TOUCH_CALIBRATION_Y
    #define TOUCH_CALIBRATION_Y            11579
  #endif
  #ifndef TOUCH_OFFSET_X
    #define TOUCH_OFFSET_X                   514
  #endif
  #ifndef TOUCH_OFFSET_Y
    #define TOUCH_OFFSET_Y                   -24
  #endif
  #ifndef TOUCH_ORIENTATION
    #define TOUCH_ORIENTATION    TOUCH_LANDSCAPE
  #endif

#endif

Also MKS TS35 needed reversed cables

Yup. I'm quite familiar with this issue since it causes a lot of headaches in Marlin's EXP1/2 numbering 🙂 Most of my EXP cables have the tabs shaved off because of it.