STM32F746DISCO Error in ''stm32746g_discovery_lcd.c''

[hans23]

Posted on April 18, 2018 at 16:34

Hi,

in the moment i build my own STM32F746 Board that is based on the STM32F746DISCO.

So i found an error in the BSP-File 'stm32746g_discovery_lcd.c'.

I use a new LCD Display with touch (other than on DISCO) and changed the SDRAM to 32-Bit databus. So i must change some processorpins!

In STM32F746DISCO the pin PI13 is named 'LCD_INT'. This is the signal 'TS_INT_PIN' in the CUBE software. This is the interrupt output of the touchscreen controller! But this interrupt function of the touchscreen is not used in the CUBE examples!

Now in the function '__weak void BSP_LCD_MspInit(LTDC_HandleTypeDef *hltdc, void *Params)' there is this pin programmed as (see bold text):

  gpio_init_structure.Pin       = GPIO_PIN_9 | GPIO_PIN_10 | \

                                                GPIO_PIN_13 | GPIO_PIN_14 | GPIO_PIN_15; // Here PIN_13 is wrong!  gpio_init_structure.Mode      = GPIO_MODE_AF_PP;  gpio_init_structure.Alternate = GPIO_AF14_LTDC;  HAL_GPIO_Init(GPIOI, &gpio_init_structure);

With this PIN_13 assignment as AF14 the processor outputs the signal 'LCD_VSYNC' at PI13  and this output is connected to the interrupt output of the touch controller!

i measured at this pin the signal 'LCD_VSYNC' with a scope!!!! So we have 2 outputs connected together => we have a collision!!

I removed PIN13 from the code and no more collision!

Best regards

Werner

[Amel NASRI]

Posted on July 13, 2018 at 17:43

Hi

Neuschwander.H.W

,

Even with delay, please note that the problem you reported isn&39t lost.

So thanks for highlighting the issue, it is reported to our development team in order to be fixed in coming versions of the BSP driver for STM32746G-Discovery board.

-Amel