Improve BLE Connection Reliability by Enabling Software Coexistence (#8683)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/esp32_ble_tracker/__init__.py

@@ -44,6 +44,7 @@ CONF_ESP32_BLE_ID = "esp32_ble_id"
 CONF_SCAN_PARAMETERS = "scan_parameters"
 CONF_WINDOW = "window"
 CONF_ON_SCAN_END = "on_scan_end"
+CONF_SOFTWARE_COEXISTENCE = "software_coexistence"
 
 DEFAULT_MAX_CONNECTIONS = 3
 IDF_MAX_CONNECTIONS = 9
@@ -203,6 +204,7 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_ON_SCAN_END): automation.validate_automation(
                 {cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(BLEEndOfScanTrigger)}
             ),
+            cv.OnlyWith(CONF_SOFTWARE_COEXISTENCE, "wifi", default=True): bool,
         }
     ).extend(cv.COMPONENT_SCHEMA),
 )
@@ -310,6 +312,8 @@ async def to_code(config):
 
     if CORE.using_esp_idf:
         add_idf_sdkconfig_option("CONFIG_BT_ENABLED", True)
+        if config.get(CONF_SOFTWARE_COEXISTENCE):
+            add_idf_sdkconfig_option("CONFIG_SW_COEXIST_ENABLE", True)
         # https://github.com/espressif/esp-idf/issues/4101
         # https://github.com/espressif/esp-idf/issues/2503
         # Match arduino CONFIG_BTU_TASK_STACK_SIZE
@@ -331,6 +335,8 @@ async def to_code(config):
 
     cg.add_define("USE_OTA_STATE_CALLBACK")  # To be notified when an OTA update starts
     cg.add_define("USE_ESP32_BLE_CLIENT")
+    if config.get(CONF_SOFTWARE_COEXISTENCE):
+        cg.add_define("USE_ESP32_BLE_SOFTWARE_COEXISTENCE")
 
 
 ESP32_BLE_START_SCAN_ACTION_SCHEMA = cv.Schema(

esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp

@@ -21,6 +21,10 @@
 #include "esphome/components/ota/ota_backend.h"
 #endif
 
+#ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
+#include <esp_coexist.h>
+#endif
+
 #ifdef USE_ARDUINO
 #include <esp32-hal-bt.h>
 #endif
@@ -194,9 +198,17 @@ void ESP32BLETracker::loop() {
     https://github.com/espressif/esp-idf/issues/6688
 
   */
-  if (this->scanner_state_ == ScannerState::IDLE && this->scan_continuous_ && !connecting && !disconnecting &&
+  if (this->scanner_state_ == ScannerState::IDLE && !connecting && !disconnecting && !promote_to_connecting) {
-      !promote_to_connecting) {
+#ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
-    this->start_scan_(false);  // first = false
+    if (this->coex_prefer_ble_) {
+      this->coex_prefer_ble_ = false;
+      ESP_LOGD(TAG, "Setting coexistence preference to balanced.");
+      esp_coex_preference_set(ESP_COEX_PREFER_BALANCE);  // Reset to default
+    }
+#endif
+    if (this->scan_continuous_) {
+      this->start_scan_(false);  // first = false
+    }
   }
   // If there is a discovered client and no connecting
   // clients and no clients using the scanner to search for
@@ -213,6 +225,13 @@ void ESP32BLETracker::loop() {
           ESP_LOGD(TAG, "Promoting client to connect...");
           // We only want to promote one client at a time.
           // once the scanner is fully stopped.
+#ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
+          ESP_LOGD(TAG, "Setting coexistence to Bluetooth to make connection.");
+          if (!this->coex_prefer_ble_) {
+            this->coex_prefer_ble_ = true;
+            esp_coex_preference_set(ESP_COEX_PREFER_BT);  // Prioritize Bluetooth
+          }
+#endif
           client->set_state(ClientState::READY_TO_CONNECT);
         }
         break;

esphome/components/esp32_ble_tracker/esp32_ble_tracker.h

@@ -299,6 +299,9 @@ class ESP32BLETracker : public Component,
   int discovered_{0};
   int searching_{0};
   int disconnecting_{0};
+#ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
+  bool coex_prefer_ble_{false};
+#endif
 };
 
 // NOLINTNEXTLINE

tests/components/esp32_ble_tracker/test.esp32-ard.yaml

@@ -1,4 +1,5 @@
 <<: !include common.yaml
 
 esp32_ble_tracker:
+  software_coexistence: true
   max_connections: 3

tests/components/esp32_ble_tracker/test.esp32-c3-ard.yaml

@@ -2,3 +2,4 @@
 
 esp32_ble_tracker:
   max_connections: 3
+  software_coexistence: false

tests/components/esp32_ble_tracker/test.esp32-c3-idf.yaml

@@ -2,3 +2,4 @@
 
 esp32_ble_tracker:
   max_connections: 9
+  software_coexistence: false

tests/components/esp32_ble_tracker/test.esp32-idf.yaml

@@ -1,4 +1,5 @@
 <<: !include common.yaml
 
 esp32_ble_tracker:
+  software_coexistence: true
   max_connections: 9