Short answer

ESP32 status LED does not blink. What should I check first?

  • Confirm the GPIO in firmware matches this board. GPIO2 is common on ESP32-DevKit; many C3 boards use GPIO8. Copying the pin from another chip is the usual miss.
  • The lamp on a DevKit is not the lamp on your product. A custom board needs its own LED, series resistor (often 220Ω–1kΩ) and a hole in the housing.
  • Drive the LED from 3.3V logic. Do not hang it on a 5V pin.
  • If the pin toggles on a meter but the lamp is dark, the footprint polarity or the resistor is wrong — not the example.

中文

短答

ESP32 状态灯不闪，先查什么？

  • 先核对固件里的 GPIO 是不是这块板的脚。ESP32-DevKit 常见 GPIO2，很多 C3 是 GPIO8。从别的芯片抄脚号是最常见的原因。
  • 开发板上的灯不是你产品上的灯。自己的板要有 LED、限流电阻（常见 220Ω–1kΩ）和外壳开孔。
  • 用 3.3V 逻辑去推灯，不要接到 5V 脚。
  • 表笔能量到脚在跳、灯仍不亮，多半是封装方向或电阻，不是例程本身。