TouchGFX: Generated Code Using Pins on Pins Used for Other Features

[KMew]

Hello,

I am using the STM32H7B3I-EVAL evaluation board to develop an understanding on using a custom board that has an LCD display. I am dissecting the code and there is something inconsistent that I am trying to understand.

My steps were as followed:

1) Use CubeMX to bring up the code from scratch, adding the TouchGFX 4.20.0 software package.

2) Open the ApplicationTemplate.touchgfx.part file to generate the code for the UI.

3) Made a basic display UI (one screen with a red background, just to test).

The code works without issue, but I am looking through the TouchGFX folder to understand the code and there is a file created:

TouchGFXGPIO.cpp ( I have attached it).

It's claiming it's using 4 signals (VSYNC_FREQ, RENDER_TIME, FRAME_RATE, MCU_ACTIVE), which toggles the following pins:

// VSYNC_FREQ - Pin PA4

// RENDER_TIME - Pin PG13

// FRAME_RATE - Pin PB15

// MCU_ACTIVE - Pin PG12

On the evaluation board, those pins are used for different features entirely.

PA4 - DCMI_PIXCLK or I2S6_EXT_SD

PG13 - LED1

PB15 - T_VCP_RX

PG12 - SDIO2_D3

Despite the connection to these pins, I am surprised the code still works. Can anyone explain the purpose of this file and why triggering these pins are necessary?

[Romain DIELEMAN]

Hi,

​

Those pins are not necessary, we reference them if people want to check the performance of their projects that is all :thumbs_up: Here is the article in the online documentation where we explain how to use them.

You can use the pins for whatever else you want, those were just arbitrary/random pins selected as they are not used in the original TouchGFX Board Setup for the STM32H7B3eval available in TouchGFX Designer . Others pins can be been used in your project if you still want performance check.

/Romain