[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.

[jmz52]

@thisiskeithb, please check following configuration:
In Configuration.h add #define TFT_DRIVER ST7796
Change SPIx.Init.BaudRatePrescaler to SPI_BAUDRATEPRESCALER_64 in https://github.com/jmz52/Marlin/blob/H7-wip/Marlin/src/HAL/STM32/tft/tft_spi.cpp#L64

[thisiskeithb]

In Configuration.h add #define TFT_DRIVER ST7796

Shouldn't that be set via conditionals when BTT_TFT35_SPI_V1_0 is enabled? :

Marlin/Marlin/src/inc/Conditionals_LCD.h

Lines 1474 to 1478 in ef3f484

	#if EITHER(MKS_TS35_V2_0, BTT_TFT35_SPI_V1_0) // ST7796
	#define TFT_DEFAULT_DRIVER ST7796
	#define TFT_DEFAULT_ORIENTATION TFT_EXCHANGE_XY
	#define TFT_RES_480x320
	#define TFT_INTERFACE_SPI

I defined it anyway and updated SPI_BAUDRATEPRESCALER_4 to SPI_BAUDRATEPRESCALER_64, but I still get a white screen with BTT_TFT35_SPI_V1_0.

[jmz52]

The are a bit different.
TFT_DEFAULT_DRIVER is a fall-back value is case driver detection fails.
TFT_DRIVER force the result, bypassing detection completely.

As I've found the H7 driver detection code only worked in half-duplex SPI (used by ST7735) but it hangs in full-duplex mode.

With updated code my TS35 is now displays proper UI, but touch is not working. This could be either code issue or wiring mess issue.
@thisiskeithb, please check if there are any improvements with your screens.

Update
Touch problem was a code issue.
MKS TS35 is now fully functional, but BTT TFT35 SPI V1.0 uses touch with software SPI and I lack the hardware needed to test it.

[thisiskeithb]

please check if there are any improvements with your screens

Success!

We'll have to tweak some pins files to differentiate between MKS_TS35_V2_0 & BTT_TFT35_SPI_V1_0 since HAS_SPI_TFT does not work for both (per my comment above).

Touch also worked on the BTT_TFT35_SPI_V1_0 once I remembered to reset the EEPROM to clear out the saved values from the MKS build 😆

[thisiskeithb]

@jmz52: Other than refactoring / fixing the HAS_SPI_TFT macro in the various pins files to separate MKS & BTT SPI TFTs, is there anything you're waiting on for a PR? I plan to replace the SKR 2 in my B1 SE Plus with an SKR 3, so your work on the SPI TFT code will be a welcome addition!

[jmz52]

I was waiting for #25359 to avoid conflicts in initialization section
Now it is merged and next week I should have time to create PR for H7

[jmz52]

Please retest code from new branch - https://github.com/jmz52/Marlin/tree/stm32h7-tft-spi

[thisiskeithb]

Please retest code from new branch - https://github.com/jmz52/Marlin/tree/stm32h7-tft-spi

Paired with my to-be-submitted PR to split up the HAS_SPI_TFT pins, this mostly works with BTT_TFT35_SPI_V1_0 & MKS_TS35_V2_0.

SPEAKER on MKS_TS35_V2_0 causes the graphics to go haywire when you send a tone with M300. Clicking the encoder or touching the TFT fixes it, but I'm trying some different pin options to see if I can get that to stop.

SPEAKER on BTT_TFT35_SPI_V1_0 works fine.

Here's the pins_BTT_SKR_V3_0_common.h diff required to support both BTT_TFT35_SPI_V1_0 & MKS_TS35_V2_0 (similar changes will need be done to other pins files):

expand me:

diff --git a/Marlin/src/pins/stm32h7/pins_BTT_SKR_V3_0_common.h b/Marlin/src/pins/stm32h7/pins_BTT_SKR_V3_0_common.h
index 09b305f..38f3b1e 100644
--- a/Marlin/src/pins/stm32h7/pins_BTT_SKR_V3_0_common.h
+++ b/Marlin/src/pins/stm32h7/pins_BTT_SKR_V3_0_common.h
@@ -455,6 +455,92 @@
     #define BTN_EN1                  EXP2_03_PIN
     #define BTN_EN2                  EXP2_05_PIN
 
+  #elif HAS_SPI_TFT                               // Config for Classic UI (emulated DOGM) and Color UI
+
+    #define TFT_SCK_PIN              EXP2_02_PIN
+    #define TFT_MISO_PIN             EXP2_01_PIN
+    #define TFT_MOSI_PIN             EXP2_06_PIN
+
+    #define BTN_EN1                  EXP2_03_PIN
+    #define BTN_EN2                  EXP2_05_PIN
+
+    #ifndef TFT_WIDTH
+      #define TFT_WIDTH                    480
+    #endif
+    #ifndef TFT_HEIGHT
+      #define TFT_HEIGHT                   320
+    #endif
+
+    #if ENABLED(BTT_TFT35_SPI_V1_0)
+
+      #define TFT_CS_PIN             EXP2_04_PIN
+      #define TFT_DC_PIN             EXP2_07_PIN
+      #define TFT_A0_PIN              TFT_DC_PIN
+
+      #define TOUCH_INT_PIN          EXP1_07_PIN
+      #define TOUCH_MISO_PIN         EXP1_06_PIN
+      #define TOUCH_MOSI_PIN         EXP1_03_PIN
+      #define TOUCH_SCK_PIN          EXP1_05_PIN
+      #define TOUCH_CS_PIN           EXP1_04_PIN
+
+      #ifndef TOUCH_CALIBRATION_X
+        #define TOUCH_CALIBRATION_X        17540
+      #endif
+      #ifndef TOUCH_CALIBRATION_Y
+        #define TOUCH_CALIBRATION_Y       -11388
+      #endif
+      #ifndef TOUCH_OFFSET_X
+        #define TOUCH_OFFSET_X               -21
+      #endif
+      #ifndef TOUCH_OFFSET_Y
+        #define TOUCH_OFFSET_Y               337
+      #endif
+      #ifndef TOUCH_ORIENTATION
+        #define TOUCH_ORIENTATION TOUCH_LANDSCAPE
+      #endif
+
+    #elif ENABLED(MKS_TS35_V2_0)
+
+      #define TFT_CS_PIN             EXP1_07_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
+
+      #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
+
   #else
 
     #define LCD_PINS_RS              EXP1_04_PIN
@@ -513,27 +599,6 @@
   #endif
 #endif
 
-#if HAS_SPI_TFT
-  //
-  // e.g., BTT_TFT35_SPI_V1_0 (480x320, 3.5", SPI Stock Display with Rotary Encoder in BIQU B1 SE)
-  //
-  #define TFT_CS_PIN                 EXP2_04_PIN
-  #define TFT_A0_PIN                 EXP2_07_PIN
-  #define TFT_SCK_PIN                EXP2_02_PIN
-  #define TFT_MISO_PIN               EXP2_01_PIN
-  #define TFT_MOSI_PIN               EXP2_06_PIN
-
-  #define TOUCH_INT_PIN              EXP1_07_PIN
-  #define TOUCH_MISO_PIN             EXP1_06_PIN
-  #define TOUCH_MOSI_PIN             EXP1_03_PIN
-  #define TOUCH_SCK_PIN              EXP1_05_PIN
-  #define TOUCH_CS_PIN               EXP1_04_PIN
-
-  #define BTN_EN1                    EXP2_03_PIN
-  #define BTN_EN2                    EXP2_05_PIN
-  #define BTN_ENC                    EXP1_02_PIN
-#endif
-
 //
 // NeoPixel LED
 //

Test config diff:

expand me:

diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index 8818b04..e82601d 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -37,6 +37,10 @@
  */
 #define CONFIGURATION_H_VERSION 02010300
 
+// Define TFTs here for faster testing
+#define MKS_TS35_V2_0
+//#define BTT_TFT35_SPI_V1_0
+
 //===========================================================================
 //============================= Getting Started =============================
 //===========================================================================
@@ -67,7 +71,7 @@
 
 // Choose the name from boards.h that matches your setup
 #ifndef MOTHERBOARD
-  #define MOTHERBOARD BOARD_RAMPS_14_EFB
+  #define MOTHERBOARD BOARD_BTT_SKR_V3_0_EZ
 #endif
 
 /**
@@ -78,7 +82,7 @@
  *
  * :[-1, 0, 1, 2, 3, 4, 5, 6, 7]
  */
-#define SERIAL_PORT 0
+#define SERIAL_PORT -1
 
 /**
  * Serial Port Baud Rate
@@ -2289,13 +2293,13 @@
  *   M501 - Read settings from EEPROM. (i.e., Throw away unsaved changes)
  *   M502 - Revert settings to "factory" defaults. (Follow with M500 to init the EEPROM.)
  */
-//#define EEPROM_SETTINGS     // Persistent storage with M500 and M501
+#define EEPROM_SETTINGS       // Persistent storage with M500 and M501
 //#define DISABLE_M503        // Saves ~2700 bytes of flash. Disable for release!
 #define EEPROM_CHITCHAT       // Give feedback on EEPROM commands. Disable to save PROGMEM.
 #define EEPROM_BOOT_SILENT    // Keep M503 quiet and only give errors during first load
 #if ENABLED(EEPROM_SETTINGS)
-  //#define EEPROM_AUTO_INIT  // Init EEPROM automatically on any errors.
-  //#define EEPROM_INIT_NOW   // Init EEPROM on first boot after a new build.
+  #define EEPROM_AUTO_INIT    // Init EEPROM automatically on any errors.
+  #define EEPROM_INIT_NOW     // Init EEPROM on first boot after a new build.
 #endif
 
 // @section host
@@ -2668,7 +2672,7 @@
 // If you have a speaker that can produce tones, enable it here.
 // By default Marlin assumes you have a buzzer with a fixed frequency.
 //
-//#define SPEAKER
+#define SPEAKER
 
 //
 // The duration and frequency for the UI feedback sound.
@@ -3272,7 +3276,7 @@
  *   root of your SD card, together with the compiled firmware.
  */
 //#define TFT_CLASSIC_UI
-//#define TFT_COLOR_UI
+#define TFT_COLOR_UI
 //#define TFT_LVGL_UI
 
 #if ENABLED(TFT_COLOR_UI)
@@ -3318,7 +3322,7 @@
 //
 // Touch Screen Settings
 //
-//#define TOUCH_SCREEN
+#define TOUCH_SCREEN
 #if ENABLED(TOUCH_SCREEN)
   #define BUTTON_DELAY_EDIT      50 // (ms) Button repeat delay for edit screens
   #define BUTTON_DELAY_MENU     250 // (ms) Button repeat delay for menus
diff --git a/platformio.ini b/platformio.ini
index e3bdb6f..12f2fc4 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -13,7 +13,7 @@
 [platformio]
 src_dir      = Marlin
 boards_dir   = buildroot/share/PlatformIO/boards
-default_envs = mega2560
+default_envs = STM32H723Vx_btt
 include_dir  = Marlin
 extra_configs =
     Marlin/config.ini

Related: #25579 was just merged, so rebasing https://github.com/jmz52/Marlin/tree/stm32h7-tft-spi to the latest bugfix-2.1.x will help pull in calibration values from pins files.

[thisiskeithb]

Closing since there's now a PR to add support:

• Add support for SPI TFT displays and touch screen for STM32H7 MCUs #25784

[github-actions]

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