STM32L4R9I-DISCO Touch Screen dependencies

[Du1]

I'm trying to develop a custom application, but noticed that if I disconnect the touch screen cable of the AMOLED LCD, the joystick stops working. I'm looking through code for dependencies, but I think it's not in the provided code, but something programmed into the Port Expander, anyone know how where I can find code for that and if not, how can I disable dependencies on the touchscreen so I can keep using the joystick. Thanks!

[Amel NASRI]

Hi @Du​ ,

The configuration of both the Joystick and the IO_Expander (MFX) are provided in the driver STM32Cube_FW_L4_V1.13.0\Drivers\BSP\STM32L4R9I-Discovery\stm32l4r9i_discovery.c.

Based on BSP_JOY_Init, the only dependency between the joystick and MFX is when Joy_Mode is "JOY_MODE_EXTI". So, try using "JOY_MODE_GPIO".

-Amel

[Du1 · Accepted solution]

Thanks for the answer @Amel NASRI​ 

turns out a project created by TouchGFX has two places to enable the Touch control, one is in GuiConfig.h with this:

#define GUI_SUPPORT_TOUCH         (0) // Support touchscreen

and the other is in mmi_config.h with:

#define MMI_TOUCHSCREEN_SUPPORTED    1

Disabling those was the trick to regaining access to the joystick.