STM32H745I-DISCO touch screen stopped working after debugger crash

[lmmv_ml]

My STM32H745I-DISCO touch screen stopped working after a HardFault/debugger crash while running a test app generated by STM32CubeMX ("Create project from board"). The display works perfectly but touch is completely unresponsive.

Steps already taken:

• Full chip erase + reflashed official FULL.hex (with MT25TL01G external loader)
• Verified option bytes (RDP=AA, BCM4 and BCM7 both enabled)
• Fixed reset mode from "Hardware reset" to "Software reset"
• ST-LINK firmware is up to date (V3J17M10)
• I2C4 registers show uninitialized on both cores

Display works, buttons visible, but no touch response at all.

[mƎALLEm]

Hello,

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@lmmv_ml wrote:

My STM32H745I-DISCO touch screen stopped working after a HardFault/debugger crash

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What does that mean? do you suspect the Hardfault broke the touchscreen module?

[lmmv_ml]

I am too new to this (embedded with STM32) to make any such assumption.

I just know:
* all was working on the board when I got it (demo, touch screen and all 3 samples apps

* ran a generated code app (generated by STM32CodeMX) in a Visual Studio Code STM32 setup which did not seem to work properly

* stopped the generated code app

* noticed issues with board (leds staying on when board stopped, etc)

* flashed the demo software back on the board

* screen does show the 3 samples apps

* touch screen not working (I do not have a mouse (with the right connector) that I can connect to validate if it does work with a mouse - as was suggested by some AI).

STM32CodeMX version: 6.17

board: STM32H745I-disco

Thank you for any help

[lmmv_ml]

in my previous:
"...* noticed issues with board (leds staying on when board stopped, etc)..."

should read:

"...* noticed issues with board (leds staying on when the generated app stopped, etc)..."

[mƎALLEm]

The issue is not quiet clear but since you are facing a Hardfault, the program is stopped, the screen displays something but all is frozen that's why you have the impression the touchscreen is unresponsive.

Read How to debug a HardFault on an Arm® Cortex®-M STM32

[lmmv_ml]

Thank you, looking at that.