diff --git a/backend/app/services/esp-idf-template/sdkconfig.defaults b/backend/app/services/esp-idf-template/sdkconfig.defaults
index ace8c593..9cc662ae 100644
--- a/backend/app/services/esp-idf-template/sdkconfig.defaults
+++ b/backend/app/services/esp-idf-template/sdkconfig.defaults
@@ -9,6 +9,12 @@ CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y
 # Bootloader — minimal logging to speed up QEMU boot
 CONFIG_BOOTLOADER_LOG_LEVEL_NONE=y
 
+# Default log level — WARN so users see only their Serial.print + real warnings.
+# Internal ESP-IDF info-level chatter (gpio:, wifi:, phy:) is suppressed.
+# Override per-tag with esp_log_level_set() at runtime if needed.
+CONFIG_LOG_DEFAULT_LEVEL_WARN=y
+CONFIG_LOG_DEFAULT_LEVEL=2
+
 # Watchdogs — disable for QEMU (timing is not real-time)
 CONFIG_ESP_TASK_WDT=n
 CONFIG_ESP_INT_WDT=n
@@ -38,6 +44,10 @@ CONFIG_ESP_MAIN_TASK_STACK_SIZE=8192
 # Enable C++ exceptions (some Arduino libraries require it)
 CONFIG_COMPILER_CXX_EXCEPTIONS=y
 
-# Bluetooth for BLE examples
+# Bluetooth for BLE examples — Bluedroid stack (the default arduino-esp32
+# BLEDevice.h library targets Bluedroid, not NimBLE). NimBLE-based sketches
+# (NimBLEDevice.h) will not compile under this config; flip stacks if needed.
 CONFIG_BT_ENABLED=y
-CONFIG_BT_NIMBLE_ENABLED=y
+CONFIG_BT_BLUEDROID_ENABLED=y
+CONFIG_BTDM_CTRL_MODE_BR_EDR_BLE=y
+CONFIG_BT_BLE_ENABLED=y