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TouchGFX on Custom Board with no TE pin

Iris-DM
Associate II

I have a custom board, which uses STM32H747IXH6 and MB1166 LCD screen from the related discovery board. I am trying to get TouchGFX up and running on this custom setup, but in my PCB design, I missed out the dedicated TE pin in the connector (I'm following the RaspberryPi DSI convention of DSI CLK, Data Lanes and I2C only). I can initialise the display, but I cannot get my TouchGFX application running. The process at the moment is as follows:

Init DSI Host

Reset the LCD display
Config DSI PLL
Config Host Timeouts
Config PHY Timers
Config LPCommand
Config AdaptedCommand Mode
Invert clock and data pins (to correct for PCB error)
Register busIO for OTM8009A
Init OTM8009A (as per Discovery examples)
Config Flow Control
Force RX Low Power

Init LTDC

Active low VSYNC and HSYNC polarity
803x483 total width and height (800x480 + porches)
Format RGB888
Double frame buffer
Start address 0xD0000000

Init FMC (IS42S32800J)
Init as Bank 2

Init TouchGFX

Start TouchGFX Thread 

 

Now when TouchGFX starts, taskEntry sits at OSWrappers::waitForVSync(); I assume that this VSync should be called from HAL_DSI_TearingEffectCallback in TouchGFXHAL, but this callback never fires. It appears a tearing effect is requested earlier in taskEntry by LCD_ReqTear, which in the discovery code writes OTM8009A_CMD_TEEON to the LCD driver. I have modified LCD_ReqTear to send OTM8009A_CMD_WRTESCN with a param of 533 (0x2,0x15) instead, as per the CMDMode_TearingEffect example, but the TearingEffectCallback is still not triggered.

What am I missing here? I can't attach the full project for confidentiality reasons, but I'm happy to share main.c and TouchGFXHAL.cpp 

I'm aware also that TearingEffectCallback and EndOfRefreshCallback still contain code that assumes the display is split in two (as per both the examples I have borrowed from), I wouldn't have thought this was the issue however, as neither of these callbacks ever fire.

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