How to resolve the issue of static electricity causing a system crash in an HMI (Human Machine Delivery System)?

To resolve HMI crashes caused by electrostatic discharge (ESD), it's necessary to pinpoint the path of ESD energy intrusion and the affected circuitry. Crashes typically indicate that ESD interference has caused an MCU reset, program crashes, or bus lockup. First, check all user-accessible points, such as metal casings, buttons, knobs, and interface metal casings, ensuring they are adequately insulated from internal circuitry or grounded via a low-impedance path. For plastic casings, ESD can discharge directly into internal circuitry through gaps; check the size of these gaps or add internal shielding. Focus on critical signal lines such as reset circuits, clock circuits, and power monitoring circuits. Check for parallel ESD protection devices, such as ESD3V3D3B, on these lines, and ensure their placement is away from board edges and interfaces.

Check the decoupling of power pins for the MCU and critical chips; ESD can cause momentary power drops leading to resets. For communication buses such as I2C and SPI, add series resistors and ESD protection diodes to the bus. On the software side, ensure the watchdog timer is enabled and use the `volatile` keyword on potentially affected global variables or status flags, and add anti-interference measures to interrupt service routines. By using an electrostatic gun to test and locate the failure point, targeted protection can be strengthened. Employing ESD protection devices from Yinte Electronics to protect critical nodes, combined with comprehensive hardware and software hardening, can effectively solve the problem of electrostatic-induced system crashes.