Bug Advisory Concerning Some Android Phones Being Unable to Scan the Advertising PDUs Sent by ESP32 Bluetooth LE

Bug Advisory 1/2 Bug Advisory Title Bug Advisory Concerning Some Android Phones Being Unable to Scan the Advertising PDUs Sent by ESP32 Bluetooth LE Issue Date 2024/05/10 Advisory Number AR2024-001 Serial Number NA Version V1.1 Issue Summary For ESP32 in the Wi-Fi and Bluetooth coexistence mode, when Wi-Fi is operated in the HT40 mode, it affects the configuration of Bluetooth LE, preventing some Android phones receiving the SCAN_RSP PDU sent by Bluetooth LE. As Android phones report advertising PDUs and SCAN_RSP PDU together, only receiving the advertising PDUs would lead to the packet to be discarded directly. Therefore, the mentioned issue can result in some Android phone applications being unable to scan the advertising PDUs sent by ESP32 Bluetooth LE. Impact Analysis The occurrence of this issue requires the simultaneous fulfillment of the following two conditions: 1. In Wi-Fi and Bluetooth coexistence mode 2. Wi-Fi is configured in HT40 mode, or in HT20/HT40 automatic mode and connected to an AP in HT40 mode. ESP-IDF Affected Versions: ESP-IDF Branch Affected Commit IDs Affected ESP-IDF Versions master 12fcc66 - b02c669 (excluded) NA release/v5.2 12fcc66 - c4d3d74 (excluded) v5.2-beta1 ~ v5.2-beta2 release/v5.1 d4e0de8 - 17752f9 (excluded) v5.1.1 ~ v5.1.2 release/v5.0 49f02b3 - 36c57c0 (excluded) v5.0.4 ~ v5.0.5 2/2 release/v4.4 4b2972c - 54ba0f8 (excluded) v4.4.6 release/v4.3 7e817bb - c8144ba (excluded) v4.3.6 ESP-IDF Patched Versions: ESP-IDF Branch Fixed Commit ID Fixed ESP-IDF Version master b02c669 NA release/v5.2 c4d3d74 v5.2-rc1 release/v5.1 17752f9 v5.1.3 release/v5.0 36c57c0 v5.0.6 release/v4.4 54ba0f8 v4.4.7 release/v4.3 1 c8144ba v4.3.7 1 ESP-IDF v4.3 has officially reached the end of maintenance. Espressif will no longer provide support for adding new features, fixing bugs, or addressing security issues in this version. Recommendations for Application Developers If there is a coexistence of Wi-Fi and Bluetooth in the application, and the ESP-IDF version used is among the affected versions, it is recommended to use fixed ESP-IDF versions mentioned above or versions after the fixed commit. If you encounter problems during the upgrade process, please provide the IDF version or Commit ID to Espressif. We will confirm and handle related matters as soon as possible. Revision History Date Version Release notes 2024/05/10 V1.1 Updated Fixed ESP-IDF Version description. 2024/02/07 V1.0 Initial release.