Screen goes blank with ADC Pin configuration and clock change

[berkerdemoglu]

Board Information

I am using STM32H7B3I-DK and have generated a project using the TouchGFXDesigner. I have then modified the pin configuration through STM32CubeIDE.

Problem Description

I want to read the value of a resistance (and thus the voltage) through the ADC and display it on the screen. I have looked at the board schematics and seen that I need to configure Pin PA4 to read ADC (ADC1_INP18). However, the clock needs to be reconfigured for some reason. So I run the automatic clock issue solver and flash the code to my board, where I just get a blank (white) screen.

This is really confusing to me because the tutorials I have watched on the topic never have to configure the clock and thus don't run into this issue.

Thanks in advance!

[SofLit]

Hello,

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@berkerdemoglu wrote:

So I run the automatic clock issue solver and flash the code to my board, where I just get a blank (white) screen.
This is really confusing to me because the tutorials I have watched on the topic never have to configure the clock and thus don't run into this issue.

 Need to share a screenshot of the clock message telling you need to solve the issue and also the screenshot after that automatic clock solver showing that white screen. Better to attach you ioc file before accepting to solve the clock issue.

[berkerdemoglu]

Ok I'm attaching the IOC file here after modifying the pin but not fixing the clock issues.
Also the image telling me to fix the clock config.

Just to clarify, the white screen I'm getting is on the board itself, not in CubeIDE. So the TouchGFX screen is just white.

[Osman SOYKURT · Accepted solution]

Hello @berkerdemoglu ,

Automatic clock solver should be avoided in situations like this. The issue you're having is that you're ADC frequency can't exceed 50Mhz, you need to reduce it.
PLL2P is currently 133MHz and also used by OCTOPSI so you shouldn't use that clock for your ADC. You could try to use instead PLLR3R or PER_CK since those ones are less than 50. 
But since it's preferable to have the highest value here, I recommend to use PER_CK and also you could try to change PER Source to use HSI then you'll have a maximum of 32 MHz.

Could you try that and tell us if it solves your issue?