Could ESD kill my STM32 board? OLED screen stopped working

[durna]

I’m using an STM32 board to drive an SSD1322 128×64 OLED display with my own driver library. It used to work fine without issues. Without changing the code, the display suddenly became completely unresponsive.

- Power supply shows 0A current draw (normally it used to pull around ~0.3A).

- During debug, I noticed something strange: inside MX_GPIO_Init() the code enters, but it hangs at

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

and never progresses beyond that line.

I double-checked all hardware connections multiple times, nothing seems wrong.

When I swapped to another STM32 board of the same model, everything worked again without any changes.

This makes me suspect a hardware fault on the original board (possibly ESD damage).

My questions:

- What should I pay special attention to when debugging this kind of issue?

- How can I pinpoint the exact root cause (e.g., RAM/stack corruption, HardFault analysis, hardware measurements)?

- What’s the recommended way to solve this and prevent it in the future (ESD protection, design practices, etc.)?

[AScha.3]

> What should I pay special attention to when debugging this kind of issue?

You cannot "debug" a "dead" or "sick" cpu , to find out, why its "sick".

You only can prevent it, never let an ESD on a pin...

see, what our new friend telling:

ESD prevention methods include grounding personnel with wrist straps, using ESD-safe workstations with dissipative mats and chairs, controlling humidity (40-60% RH), implementing anti-static packaging, wearing ESD-safe clothing and footwear, and using ionizers in areas where grounding is impractical. Proper education and training for personnel on ESD control are also crucial. 

Grounding & Workstations

• Wrist Straps:

  Wear anti-static wrist straps connected to a ground point to safely discharge static electricity from your body to the ground. 
• ESD Mats & Flooring:

  Use anti-static or conductive floor mats on work surfaces and install conductive flooring to prevent static build-up. 
• Grounded Chairs & Workstations:

  Ensure chairs and workstations are grounded to dissipate any static charges. 

Environmental Controls

• Humidity Control:

  Maintain a relative humidity of 40-60% to reduce the buildup of static electricity. 
• Remove Insulators:

  Eliminate static-generating items like coffee cups, regular plastic, and styrofoam from the workspace. 

Personal Protection

• ESD-Safe Clothing:

  Wear specialized anti-static clothing, gloves, and footwear to prevent static discharge from your garments. 
• Body Grounding:

  Use heel or shoe straps to ground yourself when standing and working, in addition to wrist straps. 

Tools & Storage

• Antistatic Packaging:

  Store and transport electronic components in shielded bags, tubes, and conductive containers. 
• ESD-Safe Tools:

  Use anti-static or static-dissipative tools for working with sensitive components. 

Advanced Techniques 

• Ionizers:

  Employ ionizers or ionization blowers to neutralize static charges on objects and in the air where grounding is not feasible.
• ESD-Safe Materials:

  Select appropriate ESD-safe materials and equipment for your work environment.

  btw

  Also at work, ESD and the follow up problems, is a common problem;

  especially with young/new colleagues , every one kills one or many cpu's, 

  depends on the individual learning curve.

[Andrew Neil]

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@durna wrote:

it hangs at

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

Odd that it should hang there - that's just writing a constant value into a structure element. 

Shouldn't have any hardware dependency at all.

But, if it has been hit by an ESD, then that does put it firmly into undefined behaviour territory ...

[Imen.D]

Hello @durna ,

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@durna wrote:

- What’s the recommended way to solve this and prevent it in the future (ESD protection, design practices, etc.)?

Many parameters come into account for ESD protecting, design practices. I advise you to refer to ST's guidelines AN1709, AN5612) for detailed ESD design, routing tips and recommendations improving the ESD protection.

[Imen.D]

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@durna wrote:

- What’s the recommended way to solve this and prevent it in the future (ESD protection, design practices, etc.)?