Short answer

Phone cannot find the ESP32 BLE device. What is missing?

  • Advertising must be running, and the name/UUID the phone filters on must match. A GATT server that never advertises is invisible.
  • Classic Bluetooth is not BLE. An ESP32-C3/C6/S3 board has BLE, not Bluetooth Classic audio.
  • iOS and Android cache BLE names. After a rename, forget the device or the old name stays in the picker.
  • Provisioning over BLE is a product flow. A GATT example on the bench is not yet a factory-ready connect sequence.

中文

短答

手机搜不到 ESP32 蓝牙设备，缺了什么？

  • 要在广播，手机过滤的名字/UUID 还要对上。GATT Server 若不广播，就是隐形的。
  • 经典蓝牙不是 BLE。C3 / C6 / S3 有 BLE，没有经典蓝牙音频。
  • iOS 和 Android 会缓存 BLE 名字。改名后要忽略设备，否则选择器里还是旧名。
  • 用 BLE 配网是产品流程。台上的 GATT 例程还不是产线可连的完整步骤。